Knowledge of oral cancer and preventive attitudes of Spanish dentists. Primary effects of a pilot educational intervention.

Abstract

To assess the knowledge and preventive attitudes that Spanish dentists have towards oral cancer, before and after an educational intervention.
A quasi-experimental study based on a nationwide intervention. All Spanish dentists were offered an on-site course on oral cancer. An individual questionnaire was administered before and after attending the course. The main outcome measures were systematic examination of the oral cavity, promotion of healthy habits and knowledge of clinical aspects.
440 GDPs entered the study. Age: 40.7+/-10.7, range 21-74. Professional experience: 13.9+/-8.9 years, range 0-45. Of those who participated in the study, 53.1% had never attended a course on oral cancer, 72.4% stated that they perform a systematic examination of the oral mucosa, 88.2% provided systematic counselling on tobacco cessation, and 54.7% reported that they did the same for alcohol. In addition, 32.3% advised patients to eat fruits and vegetables high in antioxidants. Professional experience was significantly associated with oral mucosa systematic examination (t= 2.9; p=0.003), advice on alcohol consumption (t=5.0; p=0.000), and on fruit and vegetable intake (t=5.1; p<0.001). None of these practices were specifically associated with knowledge on oral cancer. All areas of knowledge examined showed statistically significant improvement after the educational intervention.
The intervention appears to have improved the GDP s knowledge, confirming the importance of this national campaign.

Full text

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Med Oral Patol Oral Cir Bucal. 2010 May 1;15 (3):e422-6. Educational intervention on GDPs: A pilot study
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Journal section: Oral Medicine and Pathology doi:10.4317/medoral.15.e422
Publication Types: Research
Knowledge of oral cancer and preventive attitudes of Spanish dentists.
Primary effects of a pilot educational intervention
Juan Seoane-Lestón 1,3, Jose Velo-Noya 1, Samann Warnakulasuriya 2, Pablo Varela-Centelles 1, Antonio
Gonzalez-Mosquera 1, Manuel-Alfonso Villa-Vigil 3, Francisco Rodríguez-Lozano 3, Pedro Diz-Dios 1
1 Stomatology Department. School of Medicine and Dentistry. University of Santiago de Compostela. Santiago de Compostela.
Spain
2 Department of Oral Medicine and Pathology, WHO Collaborating Centre for Oral Cancer and PreCancer, Guy’s, King’s & St.
Thomas’ Dental Institute. Denmark Hill Campus. London. UK
3 General Dental Council. Madrid. Spain
Correspondence:
Cantón Grande nº5, apto. 1º E
E-15003 A Coruña Spain
juanmanuel.seoane@usc.es
Received: 25/04/2009
Accepted: 20/09/2009
Abstract
Objective: To assess the knowledge and preventive attitudes that Spanish dentists have towards oral cancer, before
and after an educational intervention.
Methods: A quasi-experimental study based on a nationwide intervention. All Spanish dentists were offered an
on-site course on oral cancer. An individual questionnaire was administered before and after attending the course.
The main outcome measures were systematic examination of the oral cavity, promotion of healthy habits and
knowledge of clinical aspects.
Results: 440 GDPs entered the study. Age: 40.7±10.7, range 21-74. Professional experience: 13.9±8.9 years, range
0-45. Of those who participated in the study, 53.1% had never attended a course on oral cancer, 72.4% stated that
they perform a systematic examination of the oral mucosa, 88.2% provided systematic counselling on tobacco
cessation, and 54.7% reported that they did the same for alcohol. In addition, 32.3% advised patients to eat fruits
and vegetables high in antioxidants.
Professional experience was significantly associated with oral mucosa systematic examination (t= 2.9; p=0.003),
advice on alcohol consumption (t=5.0; p=0.000), and on fruit and vegetable intake (t=5.1; p<0.001). None of these
practices were specifically associated with knowledge on oral cancer. All areas of knowledge examined showed
statistically significant improvement after the educational intervention.
Conclusions: The intervention appears to have improved the GDP´s knowledge, confirming the importance of this
national campaign.
Key words: Oral cancer, prevention, dentists, continuing dental education.
Seoane-Lestón J, Velo-Noya J, Warnakulasuriya S, Varela-Centelles P,
Gonzalez-Mosquera A, Villa-Vigil MA, Rodríguez-Lozano F, Diz-Dios
P. Knowledge of oral cancer and preventive attitudes of Spanish dentists.
Primary effects of a pilot educational intervention. Med Oral Patol Oral
Cir Bucal. 2010 May 1;15 (3):e422-6.
http://www.medicinaoral.com/medoralfree01/v15i3/medoralv15i3p422.pdf
Article Number: 2867 http://www.medicinaoral.com/
© Medicina Oral S. L. C.I.F. B 96689336 - pISSN 1698-4447 - eISSN: 1698-6946
eMail: medicina@medicinaoral.com
Indexed in:
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-Index Medicus / MEDLINE / PubMed
-EMBASE, Excerpta Medica
-SCOPUS
-Indice Médico Español

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Med Oral Patol Oral Cir Bucal. 2010 May 1;15 (3):e422-6. Educational intervention on GDPs: A pilot study
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Introduction
Oral cancer is a global health problem with increasing
rates of incidence and rising mortality rates (1), partic-
ularly in certain regions of Europe (France, Hungary,
Spain and Croatia), and in South East Asia and Brazil.
Oral cancer also has one of the lowest survival rates that
remain unaffected despite recent therapeutic advances,
mainly because of late presentation due to delays in the
diagnosis (period elapsed since the first symptom or
sign until the definitive diagnosis). Almost half of the
oral cancers are diagnosed at advanced stages, with low
5-year survival rates (20-50%), depending on tumour
sites (2). In this sense, early diagnosis is a foremost step
for reducing cancer mortality.
Taking this into account, different professional organi-
zations both in USA and Europe, have carried out cam-
paigns aimed at increasing information and awareness
among both public and dentists about the challenge of
oral cancer (3-5). Dental professional organizations can
make constructive contributions towards achieving fur-
ther improvements in professional involvement in pre-
vention, early detection, and management of oral cancer
and premalignant disease (3,5). The focus for such ac-
tions should be a need for increasing their own oral can-
cer educational programs for the public and healthcare
providers, emphasizing regular clinical oral examina-
tion (screening) and providing guidelines for investiga-
tion (including biopsy). The criteria for referral of pa-
tients with suspicious lesions have also been suggested
by oral cancer experts (3,5).
The objective of this study was to assess Spanish GDPs’
knowledge and preventive attitudes towards oral cancer
before and after an educational pilot intervention.
Subjects and Methods
During 2007, a nationwide campaign for prevention and
early diagnosis of oral cancer (“Campaña Nacional de
Prevención y diagnóstico Precoz del Cáncer Oral”) was
completed by the General Dental Council of Spain and
supported by the public (Regional Health Authorities)
and private (Spanish Association Against Cancer) insti-
tutions. This week-long campaign (26-30 March 2007)
was aimed at informing and alerting both the public and
dentists about the oral cancer problem, particularly is-
sues related to late diagnosis and challenges.
In order to increase preventive attitudes and knowledge
on oral cancer and precancer among Spanish dentists, a
4 hour updating course was designed by a panel of ex-
perts. This course was focused on the following topics:
Size of the problem (epidemiology and identification of
risk groups), preventive behaviours (systematic exami-
nation of oral mucosa, tobacco and alcohol cessation
and encouragement of high vegetable consumption),
clinical manifestations of oral cancer and precancer
(visual diagnosis), biopsy of suspicious lesions (video
on indications, technique and materials), guidelines and
protocols for referral of patients with precancer and sus-
picious lesions. This course was administered before
launching the campaign (February 2007) at all Provin-
cial Dental Councils in Spain. Moreover -and as part of
the campaign- every registered dentist in the country
received one of the 21,500 copies of a small book and a
DVD supported atlas on oral cancer.
With the intention of assessing the effect of the inter-
vention, and to guide future educational strategies, a pi-
lot study was designed. This quasi-experimental study
(pre- versus post- intervention) was based upon a 19
items self-applied questionnaire to be filled at the Pro-
vincial Dental Councils.
The questions used were broadly grouped into three
parts:
1. GDPs profiling questions (e.g. age, gender and profes-
sional experience; 4 items).
2. Questions concerning general preventive attitudes
towards oral cancer (e.g. systematic examination of the
oral cavity, alcohol, tobacco, and fruits and vegetable
consumption; 5 items).
3. Specific questions about knowledge on clinical as-
pects of oral cancer and precancer, oral biopsies of sus-
picious lesions and referral of patients with high index
of clinical suspicion (10 test items).
A copy of the questionnaire is available on request from
the authors.
To compare the profile of the study group with Span-
ish dentists’ mean age and years of professional experi-
ence these data were retrieved from records held by the
Spanish General Dental Council (SGDC).
Statistical analysis was performed by means of a SPSS
+ 11.0 statistical package. Pearson’s chi-square was used
to compare proportions and Student’s t test for compar-
ing means after assessing their conditions of use. The
level of significance chosen was 5%. Confidence inter-
vals around the mean and the proportions were calcu-
lated by the statistical program Epidat 3.1.
Results
The convenience sample studied included 440 GDPs
from 14 dental councils from all over Spain (including
Balearic and Canary islands) who attended the on-site
course. Their mean age was 40.7±10.7 years, ranging
from 21 to 74. Professional experience distributed along
a wide range of years (0 to 45), with a mean 13.9±8.9
years and a median of 14 years. On comparison, the
mean age of the Spanish dentists was 42.4 ±11.9 (95%
CI between study sample and all Spanish dentists = 0.7-
2.7) and the mean of years of professional experience
was 12± 9 years with a median of 12 years (95% CI
between study sample and all Spanish dentists = -2.76
-1.03).
A high proportion of the participants (53.1%) had never

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Med Oral Patol Oral Cir Bucal. 2010 May 1;15 (3):e422-6. Educational intervention on GDPs: A pilot study
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attended a continuous education course related to the
topic of oral cancer. When asked about their approach
to examination of the oral mucosa, a 72.4% affirmed
that they performed a systematic examination of the
oral mucosa on every patient seen in practice. An 88.2%
stated that they provided systematic counselling on to-
bacco cessation and a 54.7% did the same about alcohol.
Only a 32.3% advised their patients to eat fruit and ve-
getables with high antioxidant contents.
Professional experience was significantly associated
with preventive attitudes about systematic examination
of the oral mucosa (t= 2.9; p=0.003), advice on alco-
hol consumption (t=5.0; p<0.001), and advice on fruit
and vegetable intake (t=5.1; p<0.001). However, none of
these preventive attitudes was significantly associated
with GDPs’ knowledge on oral cancer.
All areas of knowledge examined showed statistically
significant improvement after the educational interven-
tion. They included: knowledge on the incidence of oral
cancer and lowered risks by vegetable intake, clinical
aspects and potential for malignancy of oral precancer,
clinical characteristics of oral cancer, indications for bi-
opsy and reference criteria of lesions that are suspected
to be malignant.
When GDPs’ knowledge on oral cancer and precancer
was grouped on a single variable the number of correct
answers (range 1 to 10), a significant difference could
be identified between baseline (pre-intervention mean=
4.8) and post educative intervention (mean= 7.4); (t=
20.2; p<0.001). These findings are detailed on Table 1.
Compared to their knowledge on oral cancer, GDPs’
were found to have a better knowledge on oral precan-
cerous conditions at both baseline and post intervention
(Table 2).
Table 1. Description of GDPs’ knowledge of oral cancer and precancer by specific areas. Baseline and post-educational intervention.
OC: Oral Cancer; OLP: Oral Lichen Planus
Knowledge on oral cancer and precancer
GDPs
(n= 440)
Baseline
n (%)
157 (35.8)
GDPs (n=440)
Post-intervention
n (%)
χ2
p
OC incidence in Spain
Effect of vegetable consumption on the reduc-
tion of OC incidence
Potential for malignant transformation of pre-
cancerous lesions
Clinical aspects of oral leukoplakias
Clinical aspects of OLP
Clinical aspects of actinic cheilitis
Clinical features of OC
Main sites for oral OC
Biopsy of lesions with high suspicion of malig-
nancy
Criteria for referral of patients with suspicious
lesions
356 (81.1)185.6 <0.001
82 (18.6) 270 (61.3) 167.6<0.001
142 (32.3) 332 (75.6) 165.5<0.001
343 (78.1)
316 (72)
231 (52.6)
251 (57.2)
201 (45.8)
376 (85.6)
351 (80)
315 (71.8)
291 (66.3)
377 (85.9)
8.3
9.0
35.2
7.7
157.1
<0.001
0.011
<0.001
0.005
<0.001
76 ( 17.3) 194 (44.2) 74.4<0.001
364 (82.9) 400 (91.1) 13.5 0.001
Knowledge of oral cancer
and precancer
Oral precancer
n (%)
Oral cancer
n (%)
CI(95%) for the diference bet-
wen precancer and oral cancer
0.270 - 0.146
0.212 - 0.083
0.021 - 0.113
0.250 - 0.135
0.197 - 0.760
0.118 - 0.008
p
Pre-intervention
oral leukoplakia 343 (78.1)
oral lichen planus 316 (72)
actinic cheilitis 231(52.6)
oral leukoplakia 376(85.6)
oral lichen planus 351(80)
actinic cheilitis 315(71,8)
251 (57.2)
<0.001
<0.001
0.1
<0.001
<0,001
0.06
Post-intervention291 (66.3)
Table 2. Description of GDPs’ knowledge of precancer versus oral cancer. Baseline and post-educational intervention.

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Discussion
There are a number of limitations to our study that we
ought to report. In general, the Statistics community
frowns on convenience samples. It will often difficult
to generalize the results of a convenience sample to
any population that has practical relevance. Still, con-
venience samples can provide useful information, es-
pecially in a pilot study. To interpret the findings from a
convenience sample properly, it has to be characterized
(usually in a qualitative sense) how the sample would
differ from an ideal sample that was randomly selected.
To avoid this bias and to ensure a representative sam-
ple, information about age, years of practice and type
of professional practice (private clinic or public health
system) was obtained from the files of General Dental
Council of Spain (CGOE). Using this information the
sample studied was compared to the whole Spanish
GDPs population. Absence of any significant differen-
ces suggested that our study sample was representative
of Spanish dentists on these parameters assessed.
Another potential bias could be the inclination of the
participants to acquire further knowledge about oral
cancer that could not be shared by the rest of the Spa-
nish GDPs. However, more than a half of the interviewed
dentists had never previously attended an education
course related to oral cancer. Moreover, this study had
the limitations inherent within a cross-sectional design:
in order to confirm the efficacy of this educational in-
tervention, it will be mandatory to ascertain whether
the acquisition of knowledge about oral cancer is main-
tained in the medium- and long-run besides determin-
ing whether it favours early diagnosis of oral cancer and
precancer in a cost-benefit analysis.
Dental professionals have an important role in both, pri-
mary prevention of oral cancer by encouraging healthy
lifestyles and secondary prevention by detecting oral
cancer or its precursor lesions at early stages (6). In Eu-
rope, the low prevalence of oral cancer contributes to a
low detection rate of new cases in population screen-
ing programmes. However, opportunistic screening
involves offering patients a screen when they attend a
clinic for some other, unrelated reason, particularly in
general dental practice, and this approach may be cost-
effective (7). Such screening may be more effectively
targeted to high-risk groups, particularly smokers and
alcohol users in the 40-60 year old groups (7). Moreo-
ver, new educational strategies are needed to identify
populations who are likely to be ignored and considered
at low risk, such as younger people and non-smoking
and non-drinking patients (8). Thus, the range of ages
and criteria for systematic oral examination should be
broadened.
Opportunistic screening by GDPs includes a systematic
examination of the oral mucosa during regular dental
care. In the present study, most respondents (72.4%) de-
clared to perform a systematic examination of oral soft
tissues to rule out oral precancer/cancer; this percentage
is close to the one reported by other authors in Europe
and USA (83-86%) (5, 9). Despite this fact, the ability
of the examiners to make a correct positive detection
of oral cancer (sensitivity (Sn)) remains low worldwide:
reported Sn scores varied from 0.4 to 1.0. The “Two
weeks wait” scheme was rolled out in December 2000,
for Head and Neck cancer referrals in the United King-
dom (Department of Health, 2000). An audit of this ini-
tiative indicates a high proportion of non-malignancies
are referred via the fast track system to the hospitals
due to low sensitivity of visual detector guidelines (10).
Although the specificity (Sp) ranged from 0.31 to 0.92,
most studies show low values scored for the screening
of oral cancer and precancer, which would mean that
patients with oral cancer may not be adequately referred
for the decisive diagnostic and treatment. In this sense,
it is important for a GDP to know which kind of cases
should be sent to a specialist.
Despite the fact that advice on smoking cessation, al-
cohol moderation and healthy eating is an essential and
ethical part of the dentist role, several gaps in knowledge
have been identified in GDPs’ awareness of oral cancer
risk factors and the application of preventive measures
(11). The results of this study reveal a high proportion of
Spanish GDPs (88.2%) do take advantage of their posi-
tion to advice patients on tobacco cessation. Signs of
improvement on tobacco cessation activities by the UK
dentists in primary care setting have also been reported
(12). However, only a 54.7% of the GDPs advised on
moderation of alcohol consumption, even when a ma-
jor role has been attributed to alcohol for the increased
incidence of oral cancer (13) together with its identifica-
tion as an independent risk factor for oral premalignant
lesions, regardless of the beverage type or drinking pat-
terns. Moreover, recommendations to reduce alcohol
intake have the potential to reduce incidence of oral
cancer and oral premalignant lesion in non-smokers and
smokers alike. Contrary to earlier impressions, patients
do readily accept alcohol screening and alcohol coun-
selling by the dentist (14).
Previous reports have used survey-type questionnaires
to evaluate dentists’ ability to diagnose and make pro-
per referral for treatment of oral and oropharyngeal
cancers (15). These reports provide data on perceptions
and knowledge regarding oral cancer, and also find gaps
of knowledge among their respondents particularly un-
derscoring the incidence of oral cancer and their per-
ceived potential for malignant transformation of some
precancerous lesions.
Regardless of the existence of studies that provide fur-
ther support to the beneficial effects of high intake of
vegetables and fruits on reducing the risk of developing
cancers of the oral cavity, particularly among current

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Med Oral Patol Oral Cir Bucal. 2010 May 1;15 (3):e422-6. Educational intervention on GDPs: A pilot study
e426
smokers and heavy alcohol drinkers (6), Spanish den-
tists at baseline had little knowledge of the advantages
of fruits and vegetables in reducing risks for oral cancer.
The educational program appears to have improved this
knowledge from a low 18% to a high 61%, confirming
the value of the national campaign aimed at GDPs.
Recent reports in the USA (16) and Europe (17), de-
scribe an increasing proportion of GDPs who offer oral
biopsy either on a routine or on a selective bases. Howe-
ver, their knowledge on identification of biopsy sites or
on biopsy techniques (incisional versus excisional) has
not been adequately investigated. Incisional biopsies
of lesions suspicious of malignancy represent a more
realistic approach for GDPs, but incisional biopsies at
times may lead to underdiagnosis due to sampling er-
rors (18). On the other hand, excisional biopsies under-
taken by GDPs made without oncological consideration
of lesions suspected to be malignant would allow micro-
scopic tumour remnants to remain in situ and causes de-
struction of the margins of the lesion, and thus making
a re-excision necessary and eventually neck treatment
mandatory.
Even though this intervention is considered positive, in
order to reduce professional delay in oral cancer diagno-
sis, it seems mandatory to continue with the educational
efforts aimed at training GDPs to perform a full mouth
examination in order to detect potentially malignant
and malignant disorders, with high sensitivity and spe-
cificity. The access to and the kind of healthcare system
in a particular country are also relevant, particularly the
referral system. The design of a simple, clear, fail-safe
referral scheme may diminish greatly the length of the
delay (19).
Future directions in this field should consider including
education in this field as a regular part of continuing
professional development (5) and the creation of inter-
national cooperation networks and electronic websites
containing worldwide information to ease professional
training on this topic.
In conclusion, the educational intervention appears to
have improved the GDPs’ knowledge, confirming the
value of this national campaign. The results of this
study however have a preliminary nature and need fur-
ther confirmation following a longitudinal design.
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