ArticlePDF Available

Sex with Animals (SWA): Behavioral Characteristics and Possible Association with Penile Cancer. A Multicenter Study.


Abstract and Figures

Introduction. Zoophilia has been known for a long time but, underreported in the medical literature, is likely a risk factor for human urological diseases. Aim. To investigate the behavioral characteristics of sex with animals (SWA) and its associations with penile cancer (PC) in a case-control study. Methods. A questionnaire about personal and sexual habits was completed in interviews of 118 PC patients and 374 controls (healthy men) recruited between 2009 and 2010 from 16 urology and oncology centers. Main Outcome Measures. SWA rates, geographic distribution, duration, frequency, animals involved, and behavioral habits were investigated and used to estimate the odds of SWA as a PC risk factor. Results. SWA was reported by 171 (34.8%) subjects, 44.9% of PC patients and 31.6% of controls (P < 0.008). The mean ages at first and last SWA episode were 13.5 years (standard deviation [SD] 4.4 years) and 17.1 years (SD 5.3 years), respectively. Subjects who reported SWA also reported more venereal diseases (P < 0.001) and sex with prostitutes (P < 0.001), and were more likely to have had more than 10 lifetime sexual partners (P < 0.001) than those who did not report SWA. SWA with a group of men was reported by 29.8% of subjects and SWA alone was reported by 70.2%. Several animals were used by 62% of subjects, and 38% always used the same animal. The frequency of SWA included single (14%), weekly or more (39.5%), and monthly episodes (15%). Univariate analysis identified phimosis, penile premalignancies, smoking, nonwhite race, sex with prostitutes, and SWA as PC risk factors. Phimosis, premalignant lesions, smoking, and SWA remained as risk factors in multivariate analysis. However, SWA did not impact the clinicopathological outcomes of PC. Conclusion. SWA is a risk factor for PC and may be associated with venereal diseases. New studies are required inother populations to test other possible nosological links with SWA.
Content may be subject to copyright.
Sex with Animals (SWA): Behavioral Characteristics and Possible
Association with Penile Cancer. A Multicenter Studyjsm_25121..8
Stênio de Cássio Zequi, PhD,* Gustavo Cardoso Guimarães, PhD,*
Francisco Paulo da Fonseca, PhD,* Ubirajara Ferreira, PhD,Wagner Eduardo de Matheus, PhD,
Leonardo Oliveira Reis, MD,Giuliano Amorim Aita, MD,Sidney Glina, PhD,§
Victor Silvestre Soares Fanni, MD,§Marjo Denisson Cardenuto Perez, PhD,
Luiz Renato Montez Guidoni, MD,Valdemar Ortiz, PhD,** Lucas Nogueira, MD,††
Luis Carlos de Almeida Rocha, PhD,‡‡ Gustavo Cuck, MD,§§ Walter Henriques da Costa, MD,¶¶
Ravendra Ryan Moniz, MD,¶¶ José Hipólito Dantas Jr., MD,*** Fernando Augusto Soares, PhD,††† and
Ademar Lopes, PhD*
*Urology Division of Pelvic Surgery Department, Hospital A C Camargo, São Paulo, SP, Brazil; Urology Division,
UNICAMP Universidade Estadual de Campinas, Campinas, SP, Brazil; Urologic Department, Hospital São Marcus,
Teresina, PI, Brazil; §Urology Division, Hospital Ipiranga, São Paulo, SP, Brazil; Urology Division of Surgical Department
FCMSCSP, Faculdade de Ciências Médicas da Santa Casa de São Paulo, SP, Brazil; **Urology Department, UNIFESP,
Universidade Federal de São Paulo, São Paulo, SP, Brazil; ††Urology Department, UFMG, Universidade Federal de
Minas Gerais, Belo Horizonte, MG, Brazil; ‡‡Urology Department, Hospital das Clínicas da UFPR, Universidade Federal
do Paraná, Curitiba, PR, Brazil; §§Urology Division, Hospital da Aeronáutica de São Paulo, SP, Brazil; ¶¶Urology Service,
Hospital, Geral de Carapicuíba, SP, Brazil; ***Genitourinary Diseases Disciplin, Hospital Universitário Onofre Lopes,
UFRN, Universidade Federal do Rio Grande do Norte, RN, Brazil; †††Surgical and Investigative Pathology Department,
Hospital A C Camargo, São Paulo, SP, Brazil
DOI: 10.1111/j.1743-6109.2011.02512.x
Introduction. Zoophilia has been known for a long time but, underreported in the medical literature, is likely a risk
factor for human urological diseases.
Aim. To investigate the behavioral characteristics of sex with animals (SWA) and its associations with penile cancer
(PC) in a case-control study.
Methods. A questionnaire about personal and sexual habits was completed in interviews of 118 PC patients and 374
controls (healthy men) recruited between 2009 and 2010 from 16 urology and oncology centers.
Main Outcome Measures. SWA rates, geographic distribution, duration, frequency, animals involved, and behav-
ioral habits were investigated and used to estimate the odds of SWA as a PC risk factor.
Results. SWA was reported by 171 (34.8%) subjects, 44.9% of PC patients and 31.6% of controls (P<0.008). The
mean ages at first and last SWA episode were 13.5 years (standard deviation [SD] 4.4 years) and 17.1 years (SD 5.3
years), respectively. Subjects who reported SWA also reported more venereal diseases (P<0.001) and sex with
prostitutes (P<0.001), and were more likely to have had more than 10 lifetime sexual partners (P<0.001) than those
who did not report SWA. SWA with a group of men was reported by 29.8% of subjects and SWA alone was reported
by 70.2%. Several animals were used by 62% of subjects, and 38% always used the same animal. The frequency of
SWA included single (14%), weekly or more (39.5%), and monthly episodes (15%). Univariate analysis identified
phimosis, penile premalignancies, smoking, nonwhite race, sex with prostitutes, and SWA as PC risk factors.
Phimosis, premalignant lesions, smoking, and SWA remained as risk factors in multivariate analysis. However, SWA
did not impact the clinicopathological outcomes of PC.
Conclusion. SWA is a risk factor for PC and may be associated with venereal diseases. New studies are required in
other populations to test other possible nosological links with SWA. Zequi SC, Guimarães GC, da Fonseca FP,
Ferreira U, de Matheus WE, Reis LO, Aita GA, Glina S, Fanni VSS, Perez MDC, Guidoni LRM, Ortiz V,
Nogueira L, Rocha LCA, Cuck G, da Costa WH, Moniz RR, Dantas Jr. JH, Soares FA, and Lopes A. Sex with
animals (SWA): Behavioral characteristics and possible association with penile cancer. A multicenter study.
J Sex Med **;**:**–**.
Key Words. Sex with Animals; Bestiality; Penile Cancer; Zoophilia; Risk Factor; Sexually Transmitted Diseases;
© 2011 International Society for Sexual Medicine J Sex Med **;**:**–**
Penile cancer (PC) is rare in the developed
world but frequent in poor regions [1]. Risk
factors for PC include unfavorable hygiene,
poverty, chronic balanopreputial irritation, prema-
lignant penile lesions, and smoking [2]. Human
papillomavirus (HPV) infection is associated with
approximately half of PC cases, but its role in PC
carcinogenesis has not been clearly established [3].
The role of promiscuity and other sexually trans-
mitted diseases (STDs) in PC is also not com-
pletely understood [4].
The present case-control study investigated
whether a personal history of sex with animals
(SWA), which is a common male sexual practice in
rural areas with high PC prevalence, plays a role in
PC. We also describe clinical and demographic
characteristics of this sexual behavior.
Materials and Methods
Study Design and Subjects
Data were collected at 16 tertiary urology or oncol-
ogy centers in 12 Brazilian cities (Table 1). The
subjects included new PC cases and patients previ-
ously treated for PC, all of whom were enrolled by
mail or by phone. The control group was composed
of healthy males aged 18 to 80 years seeking
medical attention for benign uropathies, check-up
or for cancer prevention. We ascertained that
control subjects lived in rural zones during child-
hood and adolescence and were exposed to animal-
contact hazards. Individuals who grew up in an
urban environment were excluded. A questionnaire
about personal and sexual habits was completed by
all subjects via an in-person semi-structured inter-
view with their physicians. This study was approved
by our institutional review boards. All subjects pro-
vided written informed consent.
The selected variables were race, age at enroll-
ment, age of first sexual relationship, history of
STD (urethritis, gonorrhea, syphilis, condyloma
acuminata, HIV infection), penile premalignant
lesions (Queyrat’s erythroplasia, Bowen’s disease,
lichen sclerosis, balanitis xerotica obliterans,
chronic balanitis), phimosis and circumcision, age
at circumcision, number of lifetime sexual partners,
smoking habits (past or current), history of sex with
prostitutes, and SWA. The SWA questions
addressed age at first and last SWA episodes, the
frequency of SWA (in days, weeks, months), and the
duration of SWA practice in complete years (com-
puted by subtracting the age at the first SWA
episode from the age at the last SWA episode, but
only if SWA duration was more than 1 year). We
investigated the animal species involved and
whether SWA was performed individually or in a
group of men, and whether SWA always occurred
with the same animal or with several animals.
Clinicopathological data for premalignant
lesions and PC (histological type, grade, 2002
TNM/UICC [5] (International Union Against
Cancer) staging, and therapeutic modality) were
obtained from medical records. A central office
managed the data bank and statistical analyses
using Statistical Package for the Social Sciences
version 15 (SPSS Inc., Chicago, IL, USA).
Statistical Analysis
Questionnaire responses from a total of 492 sub-
jects, 118 PC patients and 374 controls (3.16 con-
trols per case), were compared using logistic
regression analysis to calculate exposure odds
ratios (OR) and 95% confidence intervals (CIs) for
both groups. The modeling results reflect adjusted
incidence rate ratios. Proportions were deter-
mined using the c2test or Fisher’s exact test. Two-
sided Pvalues <0.05 and 95% CI were considered
indicators of significance. Differences in age were
Table 1 The rates of sex with animals (SWA) in Brazilian states, cities, and geographical regions
States (cities) N
SWA (%) No SWA (%)
São Paulo* (São Paulo, Campinas, Barretos, Itapevi, Carapicuíba) 287 Southeast 94 (32.8) 193 (67.2)
Minas Gerais (Belo Horizonte) 29 Southeast 11 (37.9) 18 (62.1)
Piauí (Teresina) 53 Northeast 34 (64.2) 19 (35.8)
Maranhão (São Luís) 14 Northeast 8 (57.1) 6 (42.9)
Rio Grande do Norte (Natal) 28 Northeast 8 (28.6) 20 (71.4)
Paraíba (João Pessoa) 15 Northeast 4 (26.7) 11 (73.3)
Acre (Rio Branco) 20 North 6 (30) 14 (70)
Paraná (Curitiba) 46 South 6 (13) 40 (87)
Total 492 171 (34.8) 321 (65.2)
*Nine hospitals participated from cities in São Paulo state.
The rates of SWA were 45%, 33.2%, 20%, and 13% in the northeast, southeast, north, and south, respectively.
2Zequi et al.
J Sex Med **;**:**–**
tested using Student’s t-test. All significant
explanatory variables in the univariate analysis
were entered simultaneously into a logistic regres-
sion model. We arrived at a multivariate model
using backward elimination to remove the least
significant variables one-by-one until all remain-
ing variables in the model were significant
(P<0.05 in test for homogeneity). Subsequently,
excluded explanatory variables were given another
chance to enter the final model via forward inclu-
sion, but none of the variables previously excluded
achieved statistical significance.
The majority of subjects (80.1%) were uncircum-
cised; 13.4% were circumcised as adults, 3.7% in
adolescence, and 2.8% in infancy. The PC and
control groups were homogeneous according to
age (Table 2). The PC group included more non-
whites (51.8% vs. 36.6%; P=0.006) and higher
rates of smoking (70.3% vs. 45.7%; P<0.001),
phimosis (67.8% vs. 14.4%; P<0.001), sex with
prostitutes (73.7% vs. 63.9%; P=0.049), prema-
lignant lesions, and SWA compared to the control
group (Table 2).
In the PC group, the rates of premalignant
lesions were 30.3%: 16% balanitis xerotica oblit-
erans, 12.7% chronic balanitis, 0.8% Queyrat’s
erythroplasia, and 0.8% Bowen’s disease. In the
control group, the rates of premalignancies were
4.7% (P<0.001):1.4% balanitis xerotica obliter-
ans, 2.7% chronic balanitis, 0.3% Bowen’s disease,
and 0.3% lichen sclerosis.
A total of 171 individuals (34.8%) reported
SWA (Table 1), which was more common among
PC patients (44.9%) than controls (31.6%;
P=0.008; Table 2), and among individuals with a
history of STDs than those without STDs (56.7%
vs. 43.3%; P<0.001). Subjects who reported SWA
also reported more sex with prostitutes (79.5% vs.
59.2%; P<0.001) and were more likely to have
had >10 lifetime sexual partners (64.3% vs. 44.8%;
P<0.001) compared to those who did not report
SWA. Penile premalignant lesions occurred in
14.9% of individuals with a history of SWA and in
9% of those without a history of SWA (P=0.088).
Smoking rates among individuals reporting SWA
were 56.7% vs. 48.6% for those who did not
report SWA (P=0.086).
The mean ages at first and last SWA episode
were 13.5 years (standard deviation [SD] 4.4 years)
and 17.1 years (SD 5.3 years), respectively. The
mean ages at sexual debut with humans were 16.3
years (SD 7.3 years) and 16.7 years (SD 3.6 years)
for subjects who did and did not report SWA,
respectively. Independent of SWA status, age at
first intercourse with humans was similar between
Table 2 Univariate analysis of penile cancer (PC) risks
Variable Category N PC cases (%) Controls (%) Pvalue*
Age, years Mean 57.57 (SD 14.49) Mean 58.72 (SD 13.00) Mean 57.20 (SD 14.93) 0.2972
Median: 59 Median: 58.0 Median: 59
Min: 18 Min: 25 Min: 18
Max: 90 Max: 85 Max: 90
Race White 295 58 (19.7) 237 (80.3) 0.036
Black 64 23 (35.9) 41 (64.1)
Mulato 122 34 (27.9) 88 (72.1)
Asiatic 11 03 (27.3) 08 (72.7)
History of sexually transmitted disease Yes 227 62 (27.3) 165 (72.7) 0.068
No 265 56 (21.1) 209 (78.9)
Penile premalignant lesions Yes 53 36 (67.9) 17 (32.1) <0.001
No 439 82 (18.7) 357 (81.3)
Smoking Yes 253 83 (32.7) 171 (67.3) <0.001
No 239 35 (14.7) 203 (85.3)
Phimosis Yes 134 80 (59.7) 54 (40.3) <0.001
No 358 38 (10.6) 320 (89.4)
Sex with prostitutes Yes 326 87 (27.3) 239 (72.7) 0.033
No 166 31 (18.7) 135 (81.3)
Number of sexual partners 10 237 50 (21.1) 187 (78.9) 0.090
>10 255 68 (26.7) 187 (73.3)
Sex with animals Yes 171 53 (31.0) 118 (69.0) 0.008
No 321 65 (20.2) 256 (79.8)
Student’s t-test for age.
Sex with Animals (SWA) and Penile Cancer 3
J Sex Med **;**:**–**
PC patients (17.0 years; SD 8.4 years) and controls
(16.5 years; SD 3.7 years).
SWA periodicity varied. A single SWA lifetime
episode was reported by 14% of SWA-reporting
subjects. SWA episodes were reported at frequen-
cies of twice per month (17%), monthly (15.2%),
weekly (10.5%), three times per week (10%), twice
per week (9.4%), daily (4.1%), and every other day
(5.3%). Bimonthly, semiannual, and quarterly
SWA was reported by 3.5%, 2.9%, and 2.3%,
respectively. In two cases (1.2%), the frequency
was not reported.
The duration of SWA behavior was less than 1
year in 34 individuals (19.9%). In the 137 subjects
(80.1%), it ranged from 1 to 26 years (mean 4.47
years, SD 3.8 years; median 3.0 years). Durations
of 1 to 5 years were reported by 101 individuals
(59%), and 36 subjects (21.1%) described SWA
behavior as persisting for more than 5 years. High
SWA periodicity (daily, alternate days, three or
more times per week, twice per week, biweekly,
and monthly) and long-term SWA were associ-
ated; 87.2% of individuals reporting >3 years of
SWA also reported high-periodicity SWA, com-
pared with 55.3% of those reporting <3 years of
SWA (P<0.001).
SWA with a group of men was reported by
29.8% of SWA-reporting study participants, with
similar rates reported by PC patients (34%) and
controls (28%; P=0.396). SWA was practiced
with the same animal by 38.0% of SWA practitio-
ners, with similar rates reported by PC patients
and controls (34% vs. 39.8%, respectively;
P=0.638). The number of animals involved per
individual ranged from 1 to 7. The animal types
most often cited were mares (N =80), followed by
donkeys (N =73), mules (N =57), goats (N =54),
chickens (N =27), calves (N =18), cows (N =13),
dogs (N =10), sheep (N =10), pigs (N =6), and
other species (N =3). Chickens were more fre-
quently involved in the south and southeast of the
country, with only three reports in the northeast,
where donkeys dominated the reports. Higher
SWA rates were found in the northeast (45%),
with the highest rates in Piauí and Maranhão
(Table 1).
Among the 171 men who reported SWA, 50
(29.2%) had PC. In these men, no association was
detected between PC and the number of animals
(always the same animal vs. several animals,
P=0.417), species (P=0.679), or the number of
people involved (SWA alone or in a group,
P=0.290). Individualized SWA periodicities were
not associated with PC (P=0.19). In addition,
high or low SWA periodicity was not associated
with PC. High SWA periodicity was reported by
78% of the PC patients and 68.1% of the controls
(P=0.263). Long-term SWA (>3 years) was
reported by 64% of the PC patients and 46.6% of
the controls (P=0.044). The predominant PC his-
tology was squamous cell carcinoma (50.8% well-
differentiated, 29.6% moderately differentiated,
and 11% undifferentiated). Carcinoma in situ, ver-
rucous carcinoma, sarcoma, and other forms
occurred in 2.5%, 3.4%, 0.8%, and 1.9% of PC
cases, respectively. Low grade (I/II), high grade
(III/IV), and unspecified ignored grade were indi-
cated in 76.7%, 13.8%, and 9.5% of cases, respec-
tively. Superficial tumors occurred in 55.1% of PC
cases (pTa or pTis in 6.8% and pT1 in 48.3%) and
invasive tumors (pT2) in 44.9% of PC cases.
Negative inguinal lymph nodes occurred in
72.9% of cases. Three patients (2.5%) had distant
metastases. Primary tumor treatments included
partial penile amputation (72%), total penile
amputation (10%), tumor exeresis or postectomy
(8.5%), and other treatments (9.5%). Eighty-nine
patients (75.4%) were alive without disease, and 29
(25.6%) were alive with cancer at the time of the
SWA behavior was not significantly associated
with histological type (P=0.201), grade
(P=0.310), treatment (P=0.346), pT stage
(P=0.857), pN stage (P=0.177), pM stage
(P=0.270), or clinical status (P=0.396). Univari-
ate analysis (Table 2) revealed the following risk
factors for PC: phimosis (P<0.001), premalignant
lesions (P<0.001), smoking (P<0.001), SWA
(P=0.008), race (white vs. nonwhite; P=0.007),
and sex with prostitutes (P=0.033). In the multi-
variate analysis (Table 3), phimosis (OR 10.41,
95% CI 6.12–17.67; P<0.001), premalignant
lesions (OR 3.90, 95% CI 1.88–8.09; P<0.001),
smoking (OR 2.71, 95% CI 1.59–4.62; P<0.001),
and SWA (OR 2.07, 95% CI 1.21–3.52; P=0.007)
were risk factors for PC.
The practice of having SWA has been present
since ancient times [6]. SWA is underreported in
the medical literature, but has been transmitted
through oral traditions, it is present in artistic rep-
resentations, and was prohibited by the Bible
(Exod 22:28; Lev 20:16) [6–8]. This behavior may
be interpreted as curiosity or as experiences pre-
ceding male sexual maturity [9]. Kinsey reported
that 8% of Americans had some SWA experience,
4Zequi et al.
J Sex Med **;**:**–**
and affirmed that SWA is common among teen
farmers of low intelligence [10]. Others consider
SWA as something other than a simple substitutive
phenomenon, such as a psychopathic manifesta-
tion of neurosis or psychosis [8].
In small samples of psychiatric inpatients,
medical inpatients, and psychiatric staff, the preva-
lence of bestiality (sexual contact or only fantasy)
was 55%, 10%, and 15%, respectively, but sexual
contact was verified only among male psychiatric
inpatients. All groups had similar SWA fantasy
rates [11].
In this population, the majority of subjects
reporting SWA stopped the practice around the
period that they began sexual contact with
humans; thus, in the context of the present study,
SWA must be distinguished from established bes-
tiality or zoophilia, paraphilias represented by
continuous or obsessive desires for SWA instead
of sex with human partners [5,7,9]. An online
questionnaire with 114 self-defined zoophiles
in developed countries revealed that 36% lived
in large cities and 83% were either college gradu-
ates or had completed some college. Forty-
five percent of the respondents worked in infor-
matics or technology, some of them with high
income [6]. However, third-world PC patients
exhibit the opposite socioeconomic and cultural
The motivation for this study came from the
observation that the majority of PC patients origi-
nate from poor rural zones, a typical environment
for SWA occurrence. This rural determinant was
used as a main condition in recruiting the control
population. We excluded men that grew up in an
urban environment, because PC prevalence is
anecdotal in these regions, suggesting that this
population is at little risk of developing this malig-
nancy. Furthermore, the opportunities for an
urban teenager to be in contact with animals in a
situation allowing sexual activity are restricted. In
contrast, boys in rural areas live daily with animals,
with several opportunities of having sexual contact
with them. Thus, by choosing individuals from
rural areas, we ensured that both cases and con-
trols were under the same odds of intimate contact
with animals and faced with the same decisions
regarding consummation.
In addition, the homogeneity of age between
PC patients and control subjects was fundamental.
In the last few decades, sexual freedom has favored
earlier sexual contacts, probably reducing sexual
contact with animals. An age bias would thus have
introduced additional biases into the investigation.
Our study relied on in-person semi-structured
interviews because many of the study participants
are illiterate or partially literate, which would
compromise comprehension of the questionnaire.
Although other biases may be introduced by this
format, such as inhibition or lying, the anonymity
of web-based or written questionnaires does not
imply total veracity.
SWA emerged as a risk factor for PC in the
multivariate analysis (Table 3). We hypothesize
that SWA promotes contact of penile tissues with
foreign genital mucosa, resulting in microtrauma
and exposure to the animals’ anogenital secretions,
which may be antigenic or carcinogenic for
humans. This situation would favor chronic irrita-
tion processes and subsequent dysplasia. Penile
injuries, tears, abrasions, or balanitis are known to
increase PC risk [2,4,12–16].
Additionally, 51.4% of the study population
smoked, 14% of SWA participants had premalig-
nancies, and the majority of subjects were uncir-
cumcised or circumcised later in life. This
situation is associated with other environmental
PC risk factors, such as poor hygienic conditions,
poverty, and HPV infection [2,4,12–18], which
may potentiate conditions for PC development.
The link between SWA and PC and its associa-
tion with STDs may reflect the SWA practitioners’
lifestyle. The subjects that reported SWA had
more sex with prostitutes, more sexual partners,
and more STDs than subjects who did not report
SWA; moreover, 29.8% of them practiced SWA
with a group of men, 64.9% had sex with multiple
Table 3 Multivariate analysis of penile cancer risk factors
Variable Odds ratio 95% confidence interval Pvalue
Phimosis 10.41 6.12–17.67 <0.001
Penile premalignant lesions 3.90 1.88–8.09 <0.001
Smoking 2.71 1.59–4.62 <0.001
Sex with animals 2.07 1.21–3.52 0.007
Race (nonwhite vs. white) 0.63 0.375–1.05 0.078
Sex with prostitutes 0.83 0.46–1.47 0.514
Sex with Animals (SWA) and Penile Cancer 5
J Sex Med **;**:**–**
We identified a high rate of uncircumcised
men with PC, although the role of unknown
infectious agents (virus, bacteria, or other micro-
organisms) [9,19] in interspecies sexual contact
can not be completely discarded. Some neoplasias
are associated with infections, such as links
between uterine cervical cancer or anogenital car-
cinomas and HPV infections or gastric carcinoma
and presence of Helicobacter pylori [19,20]. Recent
reports have also described a possible pathogenic
role of XMRV retrovirus [21,22] in prostate
cancer, another genital organ neoplasia, as well as
a role of prions in tumorigenesis [23]. The penis
may also be susceptible to infections in addition
to HPV. Prolonged and continuous SWA expo-
sure in our study population (60% practiced
SWA over 1–5 years and 20% for more than 5
years, many of them several times a month or
weekly) would increase the opportunities for
penile microtrauma and may facilitate exposure
to infectious agents present in the external
Speculation exists regarding cancer status as an
infectious disease in humans [24,25], as studies
have suggested that tumor cells can be transmitted
from one mammal host to another within the same
species [26,27]. PC is frequent in equines [28], but
transmission of malignancies between animals and
humans has not been reported. Virology does not
consider possible viral movement from animals to
humans except in cases of zoonosis, such as rabies
or pandemic forms of bird or swine flu. However,
the hypothesis that the HIV epidemic resulted
from simian–human virus transmission has not
been fully explored [29].
Fewer southern and northern Brazilian institu-
tions were evaluated because PC is rare in the
south [17] and the north has low population
density. SWA was more frequent in the poorest
Brazilian region, the northeast, and the rates were
lowest in the southern region, which is developed
and urbanized (Table 1). The kind of animals
involved in SWA varied according to the domestic
species that are typical of each region. The use of
the same animal by 34.5% of SWA participants
may be due to poverty, as the individual only has
one animal, or some affective relationship with the
This study was hindered by a few limitations.
We did not investigate the sexual orientation of
the SWA practitioners regarding animals or
human partners. For example, how many of these
men were engaging in sex with men? In what types
of sexual activity did the SWA-positive men and
the animals engage? We assumed that our study
subjects penetrated the animal vaginally or anally;
we did not investigate other possibilities. We did
not evaluate condom use, but we think that during
the period in which these patients participated in
SWA (before the “AIDS era”), condom use was
not as widespread as it is nowadays. Specific patho-
logical features or clinical outcomes of PC were
not detected in the sample, probably due to the
sample size and the nature of the retrospective data
from several institutions with different treatment
protocols. A central pathological review in associa-
tion with a molecular investigation of HPV in a
large PC cohort is underway.
Our findings were based on self-reported
history of SWA. Since self-report surveys may be
questionable and are subject to recall bias, the ideal
would be to design observational prospective
cohort studies. However, we reiterate the several
technical and ethical difficulties involved in a study
of this nature on this issue, beyond the assumption
that the practice of SWA could put patients under
risk of morbid conditions.
Although this study reflects the sexual practices
of a population that occurred decades ago (espe-
cially during the adolescence of the subjects), SWA
is a worldwide practice. There are several zoo-
philic associations or clubs in developed countries
[7] and many “zoo” web sites and virtual commu-
nities on the Internet [6] that are frequently asso-
ciated with pornographic content, and may
constitute a global health concern. Studies must be
performed in several countries and civilizations
with different incidences of PC and STDs, as well
as on rural, indigenous and urban communities, on
females, and in urological cancer facilities. Con-
sidering future prevention strategies, investiga-
tions of SWA in Africa would be interesting, as
studies have already demonstrated a protective
role of male circumcision against several STDs
[30–32]. Novel possible associations between
SWA and urological diseases might be tested,
including non-traumatic urethral stenosis, idio-
pathic infertility, and chronic prostatitis. Health
campaigns should be discussed to promote the
refutation of SWA in target populations. In
extreme refractory cases, condom use or other
barrier methods should be suggested to minimize
the risks of this sexual option, although this is
ethically debatable.
SWA merits serious scientific attention due to
its high prevalence and associated risks for PC and
perhaps STDs. Initiatives to eradicate SWA
should be considered.
6Zequi et al.
J Sex Med **;**:**–**
The authors thank the Penile Cancer Study Group
(PCSG) members: Sandro Nassar Cardoso, MD
(Urology Division, Hospital Ipiranga, São Paulo, SP,
Brazil), Roni de Carvalho Fernandes, MD (Urology Divi-
sion of Surgical Department FCMSCSP, Faculdade de
Ciências Médicas da Santa Casa de São Paulo, SP, Brazil),
Jose Vassalo, PhD (Surgical and Investigative Pathology
Department, HospitalACCamargo, São Paulo, SP,
Brazil), Fernando Assis Melo, MD (Urology Service,
FUNDACRE, Fundação Hospitalar do Acre, Rio Branco,
AC, Brazil), José Ribamar Rodrigues Calixto, MD
(Urology Departament, Hospital Universitário da Uni-
versidade Federal do Maranhão, MA, Brazil), Marcus
Mattos, MD (Urology Service, Hospital Geral de Itapevi,
SP, Brazil), Daniel Damião Gomes Seabra, PhD (Urology
Department, Hospital do Câncer de Barretos, Fundação
Pio XII, Barretos, SP, Brazil), Cristiano Utida, MD
(Urology Department, UNIFESP, Universidade Federal
de São Paulo, São Paulo, SP, Brazil), Fábio Martinez de
Melo, MD (Urology Division, Hospital Napoleão Laure-
ano, João Pessoa, PB, Brazil), Djalma de Carvalho
Moreira Filho, PhD (Public Health and Preventive Medi-
cine Department of UNICAMP, Universidade Estadual
de Campinas, Brazil).
Corresponding Author: Stênio de Cássio Zequi, PhD,
Urology Division of Pelvic Surgery Department, Hos-
pital A C Camargo, Rua Professor Antônio Prudente,
211, São Paulo 01509 010, Brazil. Tel: 5511 2189 5000;
Fax: 5511 38849103; E-mail:,
Conflict of Interest: None.
Statement of Authorship
Category 1
(a) Conception and Design
Stênio de Cássio Zequi
(b) Acquisition of Data
Stênio de Cássio Zequi; Wagner Eduardo de
Matheus; Leonardo Oliveira Reis; Giuliano
Amorim Aita; Victor Silvestre Soares Fanni; Luiz
Renato Montez Guidoni; Lucas Nogueira; Gustavo
Cuck; Walter Henriques da Costa; Ravendra Ryan
Moniz; José Hipólito Dantas Jr.
(c) Analysis and Interpretation of Data
Stênio de Cássio Zequi; Gustavo Cardoso Guima-
rães; Francisco Paulo da Fonseca; Leonardo
Oliveira Reis; Giuliano Amorim Aita; Sidney Glina;
Valdemar Ortiz; Luis Carlos de Almeida Rocha;
Fernando Augusto Soares; Marjo Denisson Carde-
nuto Perez; Ademar Lopes
Category 2
(a) Drafting the Article
Stênio de Cássio Zequi; Gustavo Cardoso Guima-
rães; Leonardo Oliveira Reis; Francisco Paulo da
Fonseca; Ademar Lopes; Fernando Augusto Soares;
Sidney Glina; Wagner Eduardo de Matheus;
Gustavo Cuck; Walter Henriques da Costa
(b) Revising It for Intellectual Content
Stênio de Cássio Zequi; Ubirajara Ferreira;
Giuliano Amorim Aita; Victor Silvestre Soares
Fanni; Marjo Denisson Cardenuto Perez; Luiz
Renato Montez Guidoni; Valdemar Ortiz; Lucas
Nogueira; Luis Carlos de Almeida Rocha; Ravendra
Ryan Moniz; José Hipólito Dantas Jr.
Category 3
(a) Final Approval of the Completed Article
Stênio de Cássio Zequi; Gustavo Cardoso Guima-
rães; Francisco Paulo da Fonseca; Ubirajara Fer-
reira; Wagner Eduardo de Matheus; Leonardo
Oliveira Reis; Giuliano Amorim Aita; Sidney Glina;
Victor Silvestre Soares Fanni; Marjo Denisson
Cardenuto Perez; Luiz Renato Montez Guidoni;
Valdemar Ortiz; Lucas Nogueira; Luis Carlos de
Almeida Rocha; Gustavo Cuck; Ravendra Ryan
Moniz; José Hipólito Dantas Jr.; Fernando Augusto
Soares; Ademar Lopes
1 Curado MP, Edwards B, Shin HR, Storm H, Ferlay J, Heanue
M, Boyle P. Cancer incidence in five continents. Vol. IX
[IARC Scientific Publications, 160]. Lyon: IARC; 2007.
2 Pow-Sang MR, Ferreira U, Pow-Sang JM, Nardi AC, Deste-
fano V. Epidemiology and natural history of penile cancer.
Urology 2010;76(1 suppl):S2–6.
3 Miralles-Guri C, Bruni L, Cubilla AL, Castellsagué X, Bosch
FX, de Sanjosé S. Human papillomavirus prevalence and type
distribution in penile carcinoma. J Clin Pathol 2009;62:870–8.
4 Maden C, Sherman KJ, Beckmann AM, Hislop TG, Teh CZ,
Ashley RL, Daling JR. History of circumcision, medical con-
ditions, and sexual activity and risk of penile cancer. J Natl
Cancer Inst 1993;85:19–24.
5 Sobin LH, Wittekind C, eds. TNM classification of malignant
tumors. 6th edition. New York, NY: Wiley & Sons; 2002.
6 Williams CJ, Weinberg MS. Zoophilia in men: A study of
sexual interest in animals. Arch Sex Behav 2003;32:523–35.
7 Miletski H. Understanding bestiality and zoophilia. Bethesda,
MD: East-West Publishing LLC; 2002: 273 pp.
8 Shenken LI. Some clinical and psychopathological aspects of
bestiality. J Nerv Ment Dis 1964;139:137–42.
9 Karpman B. The sexual offender and his offenses: Etiology,
pathology, psychodynamics, and treatment. New York: Julian
Press; 1954.
10 Kinsey AC, Pomeroy WB, Martin CE. Sexual behavior in the
human male. Philadelphia: W.B. Saunders; 1948.
11 Alvarez WA, Freinhar JP. A prevalence study of bestiality (zoo-
philia) in psychiatric in-patients, medical in-patients and psy-
chiatric staff. Int J Psychosom 1991;38:45–7.
12 Tseng HF, Morgenstern H, Mack T, Peters RK. Risk factors
for penile cancer: Results of a population-based case-control
study in Los Angeles County (United States). Cancer Causes
Control 2001;12:267–77.
13 Daling JR, Madeleine MM, Johnson LG, Schwartz SM, Shera
KA, Wurscher MA, Carter JJ, Porter PL, Galloway DA,
McDougall JK, Krieger JN. Penile cancer: Importance of cir-
cumcision, human papillomavirus and smoking in in situ and
invasive disease. Int J Cancer 2005;116:606–16.
Sex with Animals (SWA) and Penile Cancer 7
J Sex Med **;**:**–**
14 Hellberg D, Valentin J, Eklund T, Nilsson S. Penile cancer: Is
there an epidemiological role for smoking and sexual behav-
iour? Br Med J (Clin Res Ed) 1987;295:1306–8.
15 Wideroff L, Schottenfield D. Penile cancer. In: Schottenfeld
D, Fraumeni JF, eds. Cancer epidemiology and prevention.
New York: Oxford University Press; 2006:1166–72.
16 Edlin RS, Aaronson DS, Wu AK, Blaschko SD, Yang G,
Erickson BA, McAninch JW. Squamous cell carcinoma at the
site of a Prince Albert’s piercing. J Sex Med 2010;7:2280–3.
17 Favorito LA, Nardi AC, Ronalsa M, Zequi SC, Sampaio FJ,
Glina S. Epidemiologic study on penile cancer in Brazil. Int
Braz J Urol 2008;34:587–91.
18 Crispen PL, Mydlo JH. Penile intraepithelial neoplasia and
other premalignant lesions of the penis. Urol Clin North Am
19 Velázquez E, Peix A, Gómez-Alonso A. Microorganisms and
cancer: Scientific evidence and new hypotheses. Cir Esp
20 Dalton-Griffin L, Kellam P. Infectious causes of cancer and
their detection. J Biol 2009;8:67.
21 Urisman A, Molinaro RJ, Fischer N, Plummer SJ, Casey G,
Klein EA, Malathi K, Magi-Galluzzi C, Tubbs RR, Ganem D,
Silverman RH, DeRisi JL. Identification of a novel Gammaret-
rovirus in prostate tumors of patients homozygous for R462Q
RNASEL variant. PLoS Pathog 2006;2:e25.
22 Silverman RH, Nguyen C, Weight CJ, Klein EA. The human
retrovirus XMRV in prostate cancer and chronic fatigue syn-
drome. Nat Rev Urol 2010;7:392–402.
23 Mehrpour M, Codogno P. Prion protein: From physiology to
cancer biology. Cancer Lett 2010;290:1–23.
24 Gärtner HV, Seidl C, Luckenbach C, Schumm G, Seifried E,
Ritter H, Bültmann B. Genetic analysis of a sarcoma acciden-
tally transplanted from a patient to a surgeon. N Engl J Med
25 Dingli D, Nowak MA. Cancer biology: Infectious tumour
cells. Nature 2006;443:35–6.
26 Murgia C, Pritchard JK, Kim SY, Fassati A, Weiss RA. Clonal
origin and evolution of a transmissible cancer. Cell
27 Rebbeck CA, Thomas R, Breen M, Leroi AM, Burt A. Origins
and evolution of a transmissible cancer. Evolution
28 van den Top JG, de Heer N, Klein WR, Ensink JM. Penile and
preputial tumours in the horse: A retrospective study of 114
affected horses. Equine Vet J 2008;40:528–32.
29 Gao F, Bailes E, Robertson DL, Chen Y, Rodenburg CM,
Michael SF, Cummins LB, Arthur LO, Peeters M, Shaw GM,
Sharp PM, Hahn BH. Origin of HIV-1 in the chimpanzee Pan
troglodytes troglodytes. Nature 1999;397:436–41.
30 Weiss HA, Thomas SL, Munabi SK, Hayes RJ. Male circum-
cision and risk of syphilis, chancroid, and genital herpes: A
systematic review and meta-analysis. Sex Transm Infect
31 Gray RH, Kigozi G, Serwadda D, Makumbi F, Watya S,
Nalugoda F, Kiwanuka N, Moulton LH, Chaudhary MA,
Chen MZ, Sewankambo NK, Wabwire-Mangen F, Bacon
MC, Williams CF, Opendi P, Reynolds SJ, Laeyendecker O,
Quinn TC, Wawer MJ. Male circumcision for HIV prevention
in men in Rakai, Uganda: A randomised trial. Lancet
32 Tobian AA, Serwadda D, Quinn TC, Kigozi G, Gravitt PE,
Laeyendecker O, Charvat B, Ssempijja V, Riedesel M, Oliver
AE, Nowak RG, Moulton LH, Chen MZ, Reynolds SJ, Wawer
MJ, Gray RH. Male circumcision for the prevention of HSV-2
and HPV infections and syphilis. N Engl J Med
8Zequi et al.
J Sex Med **;**:**–**
... The term "Sex With Animals" (SWA) has been used to portray human sexual behavior, wi-thout reinforcing the moral stereotypes that permeate the term bestiality or associating it with a medical diagnosis, such as zoophilia or zoophilic disorder (1). In these situations, the paraphilic di-sorder causes suffering or harm to the individual, in addition to the possibility of harming himself or others for his satisfaction (2). ...
... Behavioral factors such as autism spectrum disorder are also mentioned (5) and some psychiatric disorders (6,7), and identify characteristics associated with possible sexual orientation (8). Although the SWA practice can result in health damage such as arthritis (9), herpes B (10), anogenital traumas (11), and penile cancer (1), few studies relate this behavior to Sexually Transmitted Infections (STIs). ...
... The Northeast region has one of the highest rates, 4.5%, which may be related to the more significant extension of rural areas. Research that included Northeastern men with SWA practice identified a history of STI, without clinical or laboratory proof, greater than 50% of the sample (1,17). We hypothesize that men with a history or practice of SWA have more records of STI occurrences than those without SWA. ...
Full-text available
Purpose: Our objective was to investigate the prevalence of SWA, associated factors, relationship with STIs, and behavioral aspects in men attended at Referral Centers for STIs and acquired immunodeficiency syndrome (AIDS)/CR-STI/AIDS in northeast Brazil. Materials and methods: In this cross-sectional study, a questionnaire with sociodemographic, clinical, sexual and SWA practices information was applied to 400 men attended at two CR-STI/AIDS in Northeast Brazil on the years of 2018 and 2019. Clinical and laboratory diagnoses of STIs were confirmed in medical records. Logistic regression models were performed to identify the independent predictors for SWA. Results: The prevalence of SWA over total samples was 15.00%. Of the participants, 239 (59.75%) of the participants were diagnosed with STIs, and of these 37 (15.48%) reported SWA. Most men practiced SWA in adolescence, being the last episode more than 20 years ago, usually with asinine and mules, in vaginal route and without a condom. SWA practitioners have higher percentages of occurrence of some viral STIs. SWA was associated with increasing age, history of residence in a rural area with remained over 12 years, married or widowed/separated, heterosexuals, with less than 7 years of study, Catholics, with hepatitis B, former user of alcoholic beverages and smokers, with a history of STI and intercourse with sex workers. Conclusion: SWA practices increase STIs vulnerability. The association between hepatitis B and SWA highlights the importance of educational campaigns and conclusive studies on the topic.
... Different histological types are associated with penile cancer, such as sarcoma, melanoma and basal cell carcinoma [7,8], nevertheless, penile squamous cell carcinoma (SCC) is reported in 95% of cases worldwide [9,10]. Multiple risk factors are described, mostly related to lifestyle behaviors, such as promiscuous sexual behavior [11], history of zoophilia [12], poor hygiene [13], psoralen UV-A phototherapy [14], smoking [15] and obesity [16]. Non-circumcision (phimosis) leads to chronic inflammation conditions like posthitis, lichen sclerosus and balanitis xerotic obliterans [9] increasing the risk of developing penile cancer by 22-fold [17]. ...
Full-text available
Background Penile cancer is one of the most aggressive male tumors. Although it is preventable, the main etiologic causes are lifestyle behaviors and viral infection, such as human papillomavirus (HPV). Long-term epigenetic changes due to environmental factors change cell fate and promote carcinogenesis, being an important marker of prognosis. We evaluated epidemiological aspects of penile squamous cell carcinoma (SCC) and the prevalence of HPV infection using high-risk HPV (hrHPV) and p16 INK4A expression of 224 participants. Global DNA methylation was evaluated through 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC). Results The incidence of HPV was 53.2% for hrHPV and 22.32% for p16 INK4a . hrHPV was not related to systemic or lymph node metastasis and locoregional recurrence, nor influenced the survival rate. P16 INK4a seems to be a protective factor for death, which does not affect metastasis or tumor recurrence. Lymph node and systemic metastases and locoregional recurrence increase the risk of death. An increased 5mC mark was observed in penile SCC regardless of HPV infection. However, there is a reduction of the 5hmC mark for p16 INK4a + ( P = 0.024). Increased 5mC/5hmC ratio (> 1) was observed in 94.2% of penile SCC, irrespective of HPV infection. Despite the increase in 5mC, it seems not to affect the survival rate (HR = 1.06; 95% CI 0.33–3.38). Conclusions P16 INK4a seems to be a good prognosis marker for penile SCC and the increase in 5mC, an epigenetic mark of genomic stability, may support tumor progression leading to poor prognosis.
... Além disso, no estado do Maranhão, outro possível fator citado em artigo foi a prática de zoofilia. Acerca da contribuição desse possível fator de risco, pesquisadores acreditam que os pequenos traumas gerados no pênis pela prática e o contato com secreções de animais são os aspectos causadores do câncer de pênis (47) . No estudo realizado com pacientes portadores de câncer de pênis no Maranhão, 60% deles praticavam zoofilia (19) . ...
O câncer de pênis é uma patologia que, apesar de rara, resulta em profundos impactos emocionais e físicos no paciente. Ademais, a incidência na região Nordeste do Brasil é elevada, especialmente no estado do Maranhão, cuja incidência é a mais alta no contexto global. Nesse sentido, considerando o exposto, esse trabalho objetiva a revisão integrativa dos fatores de risco e da etiologia do câncer de pênis e destaca as particularidades de estados da região brasileira nordestina. Para tal, foi realizada uma pesquisa bibliográfica nas bases de dados PubMed e BVS no intervalo temporal de 2000 a 2020, usando os seguintes descritores na língua inglesa: “etiology”, “risk factors”, “penis”, “cancer”, “Brazil” e “Maranhao”. Como resultados, foram selecionados 20 artigos para compor a discussão do tema e fatores de risco do câncer de pênis foram identificados como os mais proeminentes e destacados nos estudos. Como exemplo, pode-se citar a ausência de circuncisão, hábitos inadequados de higiene, fatores socioeconômicos, fimose, condições inflamatórias (líquen escleroso e atrófico e balanite), infecção por papilomavírus humano e hábito de fumar. Dessa forma, foram detalhados cada um desses tópicos visando o futuro delineamento de políticas públicas pelos governantes brasileiros no enfrentamento do câncer de pênis no Brasil, em especial, na região Nordeste brasileira. Assim, espera-se que futuramente hajam menos casos dessa enfermidade no país e melhoria da perspectiva de saúde dos brasileiros.
... The cause and risk factors for penile cancer are unclear. It has been associated with multiple factors, which includes: a history of no circumcision, chronic inflammation such as balanoposthitis, phimosis, and balanitis xerotica obliterans, poor hygiene, low socioeconomic status, history of multiple sex partners, ultraviolet phototherapy, HIV and HPV infections, obesity, smoking, as well as Bowen's disease, and zoophilia [9], [10], [11], [12]. Studies conducted in Brazil also showed that men who work as farmers have a higher risk of developing penile cancer [13]. ...
Full-text available
Objective: In Indonesia, 45% of the total penile cancer cases are concentrated in Bali province, where penile cancer is ranked as the most common cancer during 2013. However, the incidences of penile cancer in Bali and other provinces in Indonesia are still unknown. The purpose of this study is to determine the age-standardized incidence rate (ASR), age-specific incidence rate (AR), and crude rate incidence (CRI) of penile cancer in Bali and other provinces in Indonesia. Methods: The data were obtained from 11 provinces in Indonesia over a period of 10 years (2004-2013). The samples were 1032 new cases of penile cancer collected manually from the registry. ASR, AR, and CRI were calculated based on the number of new penile cancer cases per 100,000 men in a given province. Indonesian population standard was used to calculate the age-standardized incidence rate. Result: There were variations on ASR, AR, and CRI for penile cancer in Indonesia. We found that the average CRI in Indonesia is 0.1 per 100,000 men. The incidence is found to be higher in Bali compared to other provinces. The average ASR in Bali is 2.1 per 100,000 men, CRI is 2.5 per 100,000 men, and the peak of AR being 12.9 per 100,000 men in the age group of 55-64 years old. The incidence of penile cancer is found to increase with age. In Bali, the peak incidence is in the 6th and 7th decades of life. The ASR and CRI of penile cancer in other provinces were less than 1 per 100,000 males. Conclusion: The highest incidence of penile cancer is found in the Bali province compared to other provinces in Indonesia. This problem requires more serious attention and further research to identify the risk factors.
... The real effect of these broad restrictions on the spreading of diseases is not known, but it appeared to decrease the spreading of the novel coronavirus in China in 2020 [8]. In Japan, the influenza season in 2020 was shorter than normal possibly because of the physical distancing [9]. Physical distancing due to COVID-19 also reduces opportunities for all close contact with ...
Full-text available
Background Similar to other coronaviruses, COVID-19 is transmitted mainly by droplets and is highly transmissible through close proximity or physical contact with an infected person. Countries across the globe have implemented public health control measures to prevent onwards transmission and reduce burden on health care settings. Social or physical distancing was found to be one of appropriate measure based on previous experience with epidemic and pandemic contagious diseases. This study aims to review the latest evidence of the impact of social or physical distancing implemented during COVID-19 pandemic towards COVID-19 and other related infectious disease transmission. Methodology The study uses PRISMA review protocol and formulation of research question was based on PICO. The selected databases include Ovid MEDLINE and Scopus. Thorough identification, screening and eligibility process were done, revealed selected 8 articles. The articles then ranked in quality through MMAT. Results A total of eight papers included in this analysis. Five studies (USA, Canada, South Korea and the United Kingdom) showed physical distancing had resulted in a reduction in Covid-19 transmission. In comparison, three other studies (Australia, South Korea and Finland) showed a similar decline on other infectious diseases (Human Immunodeficiency Virus (HIV), other sexually transmitted infections (STI), Influenza, Respiratory Syncytial Virus (RSV) and Vaccine-Preventive Disease (VPD). The degree of the distancing policy implemented differ between strict and lenient, with both result in effectiveness in reducing transmission of infectious disease. Conclusion Physical or social distancing may come in the form of extreme or lenient measure in effectively containing contagious disease like COVID-19, however the stricter the measure will give more proportionate impact towards the economy, education, mental health issues, morbidity and mortality of non-COVID-19 diseases. Since we need this measure to ensure the reduction of infectious diseases transmission in order to help flattening the curve which allow much needed time for healthcare system to prepare adequately to response, ‘Precision physical distancing” can be implemented which will have more benefit towards the survival of the community as a whole.
... (2) relativizaban la gravedad a partir de comparaciones con conductas de abuso infantil o violaciones; (3) se equiparaban otros actos históricamente estigmatizados que han logrado cierto nivel de aceptación social, (4) destacaban los beneficios de sus prácticas sexuales tanto para ellos como para los animales; (5) cuestionaban inconsistencias sociales al demonizar la zoofilia y sus dificultades para entenderla; y (6) destacaban que la zoofilia era más frecuente de lo que socialmente se admite. Zequi et al. 2012 Brasil Pacientes de 12 centros de urología (N = 492), sanos (n = 374) y con cáncer de pene (n = 118), criados en zonas rurales. ...
Full-text available
Sexual attraction towards animals disorder: Diagnostic classification based on a systematic review Abstract: Sexual intercourse between humans and animals has existed since the dawn of humanity in every place and culture of the world. Nevertheless, this issue has been scarcely approached by science. Given the wide differences in behavior and preferences among people who practice sex with animals, it is necessary to establish a subtypes classification. For this purpose, a systematic review of investigations was carried out that allowed us to select 26 empirical studies. Their analysis permitted to describe the group of Sexual Attraction Towards Animals disorder, comprising four differentiated disorders: (1) zoophilic disorder, (2) bestiality disorder, (3) sexual zoosadism, and (4) sexual attraction disorder towards animals due to medical or substance-induced illness. Additionally, the diagnostic criteria for each are proposed. Implications and limitations are discussed, as well as the value of having a classification of these disorders and the need to incorporate their study in the academic field. Keywords: Bestiality; disorders; paraphilias; zoophilia; zoosadism. Resumen: Las relaciones sexuales entre humanos y animales han existido desde los albores de la humanidad en todos los lugares y culturas del mundo. Sin embargo, han sido abordadas escasamente por la ciencia. Dadas las amplias diferencias en las conductas y preferencias entre quienes practican sexo con animales, se hace necesario establecer una clasificación de subtipos. Con ese propósito, se realizó una revisión sistemática de investigaciones que arrojó 26 estudios empíricos. El análisis de estos permitió describir el grupo de Trastornos por atracción sexual hacia animales, comprendiendo cuatro trastornos diferenciados: (1) trastorno zoofílico, (2) trastorno por bestialidad, (3) zoosadismo sexual, y (4) trastorno por atracción sexual hacia los animales debido a enfermedad médica o inducido por sustancias. Adicionalmente, se propusieron criterios diagnósticos para cada uno. Se discuten las implicancias y limitaciones, el valor de contar una clasificación de estos trastornos y la necesidad de incorporar su estudio en el ámbito académico. Palabras clave: Bestialismo; parafilias; trastornos; zoofilia; zoosadismo.
... El estudio de Zequi et al. (2012) consideró una muestra de pacientes de un centro de urología de Brasil, y no de usuarios de foros dedicados al sexo con animales. De los 492 participantes, el 34.8% indicó haber tenido alguna vez sexo con animales, siendo el 44.9% ...
Full-text available
Las relaciones sexuales entre humanos y animales han existido desde los albores de la humanidad en todos los lugares y culturas del mundo. Pese a conformar la parafilia que se presume más frecuente, la zoofilia/bestialidad se encuentra muy poco estudiada, posiblemente a partir del tabú social que genera. Este trabajo se propuso confrontar los prejuicios en torno al sexo humano-animal con los datos de las investigaciones más recientes desarrolladas. Los datos ponen en evidencia una amplia variabilidad existente entre las personas que practican sexo con animales. Adicionalmente, permiten rechazar las creencias de que el sexo humano-animal se asocia con áreas rurales, animales de granja, que sus practicantes tengan discapacidad intelectual o trastornos mentales severos o que lo hagan bajo efecto de alcohol y drogas. Además, se rechaza la idea de que el bestialismo se desarrolle netamente como una práctica casual o que se deba a la privación sexual con otros humanos. La naturaleza abusiva de sus practicantes es discutida, así como también que el sexo humano-animal sea empleado en la actualidad como una forma de experimentación sexual adolescente. Finalmente, se concluye destacando la necesidad de realizar discusiones abiertas sobre el tema, promoviendo la investigación y evitando los prejuicios, fundamentalmente en los profesionales dedicados al abordaje clínico de humanos y animales. Abstract: Sexual relationships between humans and animals have existed since the dawn of humanity in all places and cultures of the world. Despite being deemed the most frequent paraphilia, zoophilia/bestiality is poorly studied, possibly due to the social taboo it generates. This work was proposed to confront the prejudices about human-animal sex with the data of the most recent research carried out. The data show a wide variability among people who have sex with animals. In addition, they allow us to reject the beliefs that human-animal sex is associated with rural areas, farm animals, that their practitioners have intellectual disabilities or severe mental disorders, or that they do so under the influence of alcohol and drugs. Moreover, the idea that bestiality is purely developed as a casual practice or due to sexual deprivation with other humans is rejected. The abusive nature of its practitioners is discussed, as well as the assertion that human-animal sex is currently employed as a form of adolescent sexual experimentation. Finally, we conclude by highlighting the need for open discussions on the subject, promoting research and avoiding prejudices, mainly among professionals devoted to the clinical approach to humans and animals.
... The relationship between zoophilia and penile cancer was the subject of a recent study 42 . The authors consider zoophilia a risk factor and demonstrate that men who practiced sex with animals are two times more likely to develop cancer of the penis. ...
Full-text available
To determine the epidemiological, histopathological, and clinical characteristics of patients diagnosed with penile cancer in the Brazilian state of Maranhão, the region with the highest incidence worldwide. One hundred and sixteen penile cancer patients were interviewed from July 2016 to October 2018. The majority of patients lived in a rural area (57%), worked in farming (58%), had a low level of schooling or no schooling (90%), and were married or in a stable relationship (74%). The mean age was 60.4 ± 16.51 years (range, 23–93 years). Phimosis (66%), poor/moderate genital hygiene (73%), history of sexually transmitted infections (55%), and zoophilia (60%) were found in the majority of patients. Most patients had their first sexual encounter at 16.2 ± 2.8 years (range, 10–25 years), and 75% had >6 sexual partners. The most common initial symptom was pruritus (37%), and most patients waited to seek treatment (average time to treatment, 18.9 months; range, 2–84 months). Human papillomavirus (HPV)-related histologies were observed in 62% of patients. Most patients had histological grades II or III (87%), stage ≥T2 disease (84%), and lymphadenopathy at admission (42%). Penectomy was performed in 96% of patients. The population with penile cancer in the region of highest incidence in the world is marked by low socioeconomic status, high prevalence of HPV infection, and phimosis. The delay in seeking treatment is related to a very high rate of advanced cancer and aggressive surgical treatment. The high prevalence of young patients was also a striking feature.
Full-text available
Penile cancer is a rare cancer in Western countries, but is more common in parts of the developing world. Usually, it is associated with older uncircumcised men who have a long-term phymotic preputium. Here, we report a case of penile cancer in a circumcised patient, occurring 3 months after a tick bite on the head of the penis. To the best of our knowledge, this is the first report that suggests a possible association between Lyme disease and occurrence of “de novo” penile cancer. Further studies are needed to confirm this hypothesis.
Male circumcision significantly reduced the incidence of human immunodeficiency virus (HIV) infection among men in three clinical trials. We assessed the efficacy of male circumcision for the prevention of herpes simplex virus type 2 (HSV-2) and human papillomavirus (HPV) infections and syphilis in HIV-negative adolescent boys and men. We enrolled 5534 HIV-negative, uncircumcised male subjects between the ages of 15 and 49 years in two trials of male circumcision for the prevention of HIV and other sexually transmitted infections. Of these subjects, 3393 (61.3%) were HSV-2-seronegative at enrollment. Of the seronegative subjects, 1684 had been randomly assigned to undergo immediate circumcision (intervention group) and 1709 to undergo circumcision after 24 months (control group). At baseline and at 6, 12, and 24 months, we tested subjects for HSV-2 and HIV infection and syphilis, along with performing physical examinations and conducting interviews. In addition, we evaluated a subgroup of subjects for HPV infection at baseline and at 24 months. At 24 months, the cumulative probability of HSV-2 seroconversion was 7.8% in the intervention group and 10.3% in the control group (adjusted hazard ratio in the intervention group, 0.72; 95% confidence interval [CI], 0.56 to 0.92; P=0.008). The prevalence of high-risk HPV genotypes was 18.0% in the intervention group and 27.9% in the control group (adjusted risk ratio, 0.65; 95% CI, 0.46 to 0.90; P=0.009). However, no significant difference between the two study groups was observed in the incidence of syphilis (adjusted hazard ratio, 1.10; 95% CI, 0.75 to 1.65; P=0.44). In addition to decreasing the incidence of HIV infection, male circumcision significantly reduced the incidence of HSV-2 infection and the prevalence of HPV infection, findings that underscore the potential public health benefits of the procedure. ( numbers, NCT00425984 and NCT00124878.)
Microorganism involvement in cancer has been known for over a century, and different types of parasites, bacteria and viruses have been associated with oncogenic processes. Among the bacteria, the first recognised was Helicobacter pylori which causes gastric cancer and might be related to extra-gastric cancer in humans. Helicobacter hepaticus has been associated with liver cancers using animal models. Other bacteria, such as Chlamydia psitacii, Borrelia burgdorferi and Streptococcus bovis, have been associated with ocular, skin and colorectal cancers, respectively. Also, a commensal bacterium in the human intestine, Bacteroides fragilis, has been linked, very recently, with colorectal cancer using animal models. Copyright © 2010 AEC. Published by Elsevier Espana. All rights reserved.
An extensive literature search was performed using the key words squamous cell carcinoma of the penis, phimosis, circumcision, chronic balanitis, cigarette smoking, genital warts and human papillomavirus (HPV) infection. All selected studies were classified according to the level of evidence (LE). The final grades of recommendation were assigned after discussion by the full panel of the International Consultation on Penile Cancer in November 2008. The factors positively associated with invasive penile cancers include the presence of phimosis (LE 3a), tobacco smoking (LE 3a-4), chewing tobacco (LE 3a), injury to the penis (LE 3a), balanitis (LE 3a), genital warts (LE 3a), and high-risk HPV infection (LE 3a-4).
Invasive penile cancer is an aggressive malignancy that often requires partial or complete penile amputation. Premalignant penile lesions, such as penile intraepithelial neoplasia, will have been present prior to the development of invasive disease in a substantial percentage of patients. Early detection and treatment of premalignant penile lesions may prevent malignant progression while avoiding penile amputation. This review focuses on premalignant penile lesions and the associations of these lesions with the development of invasive penile cancer.