Retrospective study of correlation between high risk detection of HPV and liquid based cervical cytology for cervical cancer screening

Abstract

BACKGROUND Cervical cancer is most common in Nepalese women. Human papilloma virus (HPV) plays a main role in pathogenesis of cervical cancer. Human papilloma virus serotype 16 is the most common type followed by HPV 18. Liquid based smear cytology (LBC) is a simple, safe, non-invasive and cost effective method for the detection of squamous intraepithelial lesion or squamous cell carcinoma. The aim of this study was to correlate HPV DNA testing result with the findings of Liquid based cytology. METHODS This was a retrospective study conducted for 2 years at Department of Laboratory Medicine Pathology, Nepal Mediciti hospital from 1st may 2021 to 30th April 2023. Total of 1456 cases were included in this study. RESULTS Out of 1456 cases, 100 cases were positive for HPV. The concordance between HPV DNA test and LBC findings is 57%. The highest HPV-positive cases were seen in the age group of 31-40years. The most common HPV genotype study was HPV 16 (28%) followed by HPV 18 (27%). HPV 16 was positive in 57% of ASCUS positive cases of LBC, is statistically significant (P value-0.017). HPV 18 was positive in 37.0% of ASCUS positive cases of LBC, is not statistically significant (P value-0.018). The concordance between HPV positive detection and LBC findings is 57% and discordance is 43%. CONCLUSIONS This study shows the prevalence of HPV is higher in middle to young age group. ASCUS was common finding in LBC in HPV positive cases followed by LSIL,HSIL and SCC. However 43% of HPV positive cases were reported as negative for intraepithelial lesion (NILM) as there was no abnormality in squamous epithelial cells. Both the HPV test and cervical LBC smears are valuable tools for early detection of cervical precursor lesion. However, neither test alone provides conclusive results for comprehensive screening. So, it is recommended to use both test in combination for more accurate and reliable findings in cervical cancer screening.

Full text

49 NMMJ | Volume 5 | Number 2 | July-December 2024
Nepal Mediciti Medical Journal
Thakur Niki*, Aryal Gopi, Rana Reena
Department of Laboratory Medicine and Pathology,
Nepal Mediciti Hospital, Sainbu, Lalitpur, Nepal
Retrospective study of correlation between high risk detection
of HPV and liquid based cervical cytology for
cervical cancer screening
BACKGROUND
Cervical cancer is most common in Nepalese women. Human papilloma virus (HPV) plays a main role in pathogenesis of
cervical cancer. Human papilloma virus serotype 16 is the most common type followed by HPV 18. Liquid based smear
cytology (LBC) is a simple, safe, non-invasive and cost effective method for the detection of squamous intraepithelial lesion
or squamous cell carcinoma. The aim of this study was to correlate HPV DNA testing result with the ndings of Liquid based
cytology.
METHODS
This was a retrospective study conducted for 2 years at Department of Laboratory Medicine Pathology, Nepal Mediciti
hospital from 1st may 2021 to 30th april 2023. Total of 1456 cases were included in this study.
RESULTS
Out of 1456 cases, 100 cases were positive for HPV. The concordance between HPV DNA test and LBC ndings is 57%. The
highest HPV-positive cases were seen in the age group of 31-40years. The most common HPV genotype study was HPV 16
(28%) followed by HPV 18 (27%). HPV 16 was positive in 57% of ASCUS positive cases of LBC, is statistically signicant (P
value-0.017). HPV 18 was positive in 37.0% of ASCUS positive cases of LBC, is not statistically signicant (P value-0.018).
The concordance between HPV positive detection and LBC ndings is 57% and discordance is 43%.
CONCLUSIONS
This study shows the prevalence of HPV is higher in middle to young age group. ASCUS was common nding in LBC in HPV
positive cases followed by LSIL,HSIL and SCC. However 43% of HPV positive cases were reported as negative for intraepithelial
lesion (NILM) as there was no abnormality in squamous epithelial cells. Both the HPV test and cervical LBC smears are valuable
tools for early detection of cervical precursor lesion. However, neither test alone provides conclusive results for comprehensive
screening. So, it is recommended to use both test in combination for more accurate and reliable ndings in cervical cancer
screening.
KEYWORDS
Human papilloma virus, Liquid based smear cytology, Cervical cancer screening
ABSTRACT
*Corresponding Author |
Dr. Niki Thakur
Registrar, Pathologist
Email: nikithakur64@gmail.com
Nepal Mediciti Hospital, Sainbu, Lalitpur, Nepal
Original Article
This work is licensed under a Creative
Commons Attribution 4.0 Unported License.

50
NMMJ | Volume 5 | Number 2 | July-December 2024
Retrospective study of correlation between high risk detection of HPV | Original Article
INTRODUCTION
Cervical cancer is the most common cancers in Nepal. 1
According to the International Agency for Research on Cancer
(IARC), the incidence of cervical cancer can be reduced by 90
% through periodic screening. 2
Human papilloma virus(HPV) plays a main role in
carcinogenesis. HPV E7 stimulates the cell cycle by binding
to RB and releasing E2F, E6 AND E7 are key gene that inhibit
apoptosis to facilitate virus survival by blocking RB, P53 and
P27, leading to carcinogenesis.3
The Bethesda system (TBS) for reporting cervical/vaginal
cytological diagnosis is a uniform system for reporting
& it is useful to provide effective communication among
cytopathologists & referring physician.4 The squamous
cellular abnormalities described in TBS are as ASC (Atypical
Squamous Cells), LSIL, HSIL & Squamous cell carcinoma.The
revised 2001 Bethesda System includes changes that are
based on clinical input and advances in the understanding of
the biology of cervical cancer and the latest revision version
done in 2014. 5
In the 1990s, a new methodology was developed for the
collection and preparation of cervical cytological samples for
screening, a liquid-based cytology approved by United States
Food and Drug Administration. 6,7
More than 150 different strains of HPV are present, 40
different types of HPV genotypes are known to affect the
genital area. Based on the risk level, they are divided into
three categories: high, low and intermediate risk types. The
high-risk HPV types are 16, 18, 31, 33, 35, 39, 45, 51, 52,
56, 58, 59, 68, 73 and 82, while low-risk HPV types are HPV
6, 11, 40, 42, 43, 44, 54, 61, 70, 72 and 81 as they are only
associated with benign warts and intermediate risk types are
HPV 23, 53, 66. 8
HPV is associated with various kinds of clinical conditions that
range from innocuous lesions to cancer. Most HPV infections
are benign and generally resolve spontaneously within 1 to 5
years. 9 HPV was nally recognized as the important factor
in causing cervical cancer in 1996, by the World Health
Association, along with the European Research Organization
on genital infection and Neoplasia. 9. Most importantly
HPV 16 and 18 have been credited in causing nearly 70%
of cervical cancer worldwide. 10. Many years of consistent
studies have conrmed that the cervical infection which is
caused by the high-risk HPV types is the starting point in
causing cervical cancer. Therefore, early and timely detection
of cervical cancer is a must in order to prevent and minimize
the incidence of cervical cancer. Screening of cervical cancer
usually starts at the age of 21 years. 10 Although HPV is
necessary factor for the causation of cervical cancer, it alone
is not responsible for the cancer, Various other factors like
sexual orientation, number of sexual partner, long term use
METHODS
This was a retrospective study conducted at Department of
Laboratory Medicine and Pathology from 1st may 2021 to
16th may 2023. The proposal for the research was approved
by IRC of NMC. Detection of high risk HPV was done by RT-
PCR (REF-A28134, SN-272526621) and in sample collected
for LBC test. Only HPV positive cases were taken and
correlated with its cytological ndings. Bethseda system
2014 used to report the LBC. Specimen (Ethanol xed LBC
slides) received from Department of GYN/OBS reported.
of oral contraceptives, immune compromise condition, co-
infection with HIV or chlamydia leads to the progression of
HPV-infected precursor lesions to cancer.
Apart from the preventive measures, recent development in
the eld of HPV vaccines are also rapidly increasing.These
vaccines are design for targeting various different genotypes
of HPV. The HPV vaccines are most effective when
administered before individuals becomes sexually active and
are potentially exposed to the virus. Gardasil is an effective
HPV vaccine which targets nine different types of HPV (6,
11, 16, 18, 31, 33, 45, 52 and 58).It is usually administered
in a series of two or three doses over a period of several
months. Early diagnosis and detection of HPV is one of the
major treatment for HPV infection and subsequent cervical
cancer, since HPV cannot be cultivated in laboratory and
immunologic assays are also inadequate for the diagnosis of
HPV, cytology has become the basic tools for the diagnosis.
With the recent development in the eld of molecular science
detection of HPV by PCR has gain worldwide recognition
for its analytical sensitivity, rapid result and it’s versatility.
Currently various different commercial kits are available in the
markets that caters to the clinicians and health professionals
need for the detection of high-risk HPV genotypes. These kits
are able to detect low-risk, high-risk and intermediate-risk
HPV types depending upon the need and the type of sample
from which it can detect the virus may also vary. 11
The aim of the study was to nd out the different genotypes
of HPV present by real-time PCR in the general female
population visiting tertiary hospitals within in the Valley. We
also collected the LBC result of these patients to look for
changes in their cervical cells. This study helps in establishing
the correlation of LBC(cytology) and HPV molecular test and
aid in the screening and diagnosis of cervical cancer. This
assessment can help doctors in better risk management and
stratication of individuals with HPV detection and abnormal
ndings in LBC.

51 NMMJ | Volume 5 | Number 2 | July-December 2024
Nepal Mediciti Medical Journal
LBC were collected and prepared smears following
standard protocol. All cases of HPV detection including high
risks type (16, 18, 39, 45, 31, 33, 35, 51, 56, 59, 66, 67, 52, 58,
68) detection were included. The data analysis was done by
version SPSS version 20.
RESULTS
Total of 1456 cases. Out of 1456 cases, 100 cases were HPV
positive. Only HPV 100 positive cases, LBC report was traced
and correlated simultaneously.
The table 1 and gure 1 presents age distribution of
study patients. The ndings indicated that the majority
of participants were aged between 31 and 40 years,
representing 38.0% of the total population. This was followed
by the 20 to 30 age group, which accounted for 23.0% of
the participants. The 41 to 50 age group made up 21.0% of
the total, while 12.0% of participants were between 51 and
60 years old. The smallest proportion of participants, 6.0%,
were aged over 60. Overall, the distribution showed that the
highest concentration of participants fell within the younger
to middle-aged categories, particularly those aged 31 to 40.
Table 2 and gure 2 presents the status of positive and
negative ndings of LBC smears among 100 cases of high
risk detection of HPV. Majority of the patients were diagnosed
positive 57(57.0%) on LBC smears among HPV positive high
risk detection while 43(43.0%) of the patients were detected
with negative ndings on LBC.
Table 3 shows distribution of HPV variant positive cases with
their respective LBC cytological ndings. Overall, ASCUS was
the most common nding across all variants, affecting 33.0%
of the participants, followed by LSIL (16.0%), HSIL (7.0%), and
SCC (1.0%), while 43.0% were negative for any cytological
abnormality.
Table 1. Age distribution of study patients.
Table 2. Status of positive and negative cases of LBC
smears among HPV positive high risk detections patients.
Figure 2. Status of positive and negative cases among
patients.
Figure 1. Age distribution of study patients.
Age (in years) Frequency Percent (%)
20 to 30 23 23.0
31 to 40 38 38.0
41 to 50 21 21.0
51 to 60 12 12.0
>60 66.0
Total 100 100.0
Cases Frequency Percent (%)
Positive 57 57.0
Negative 43 43.0

52
NMMJ | Volume 5 | Number 2 | July-December 2024
Retrospective study of correlation between high risk detection of HPV | Original Article
DISCUSSION
This study was done in Nepal Mediciti Hospital. It shows
highest HPV positive in age group of 31-40 shown in table
1. This nding was in agreement with study done by Findik
S et al. where most common HPV-positive rates were found
in the 30-40 age group. 13 Our results in contrast to a study
done by Dunnel et al. which shows highest prevalence below
30 years of age13and a study done by Gupta et al. which
showed most common in age group 41-50. 8
The most common HPV genotype in our study is HPV 16
(28%) followed by HPV 18 (27%). Others were 45% which
Table 4 shows the distribution of patient age group among
different variant of HPV. So, HPV 16 is highest in age group of
20-30 and 31-40 age group. HPV 16 was not present in age
group above 60. HPV 18 and HPV others than 16 and 18 was
more common in age gorup of (31-40)years.Overall, 28.0%
participants were positive for HPV16, 27.0% for HPV18, and
45.0% for other HPV variants across all age groups
Table 4. Distribution of patient’s age among type of variant
Chi-Square Test
Variant ASCUS n(%) LSIL n(%) HSIL n(%) SCC n(%) Negative n(%) Total n(%) P-value
HPV 16 16 (57.1%) 4 (14.3%) 3 (10.7%) 1 (3.6%) 4 (14.3%) 28 (100.0%) 0.017
HPV 18 10 (37.0%) 8 (29.6%) 2 (7.4%) 0 (0.0%) 7 (25.9%) 27 (100.0%) 0.118
HPV Others 7 (15.6%) 4 (8.9%) 2 (4.4%) 0 (0.0%) 32 (71.1%) 45 (100.0%) <0.0001
Total 33 (33.0%) 16 (16.0%) 7 (7.0%) 1 (1.0%) 43 (43.0%) 100 (100.0%)
AGE (in
years)
HPV16
n(%)
HPV18
n(%)
HPV
Others
n(%)
Total
n(%)
P-value
20 to 30 12
(52.2%)
3
(13.0%)
8
(34.8%)
23
(100.0%)
0.001
31 to 40 12
(31.6%)
9
(23.7%)
17
(44.7%)
38
(100.0%)
41 to 50 2 (9.5%) 4
(19.0%)
15
(71.4%)
21
(100.0%)
51 to 60 2
(16.7%)
8
(66.7%)
2
(16.7%)
12
(100.0%)
>60 0
(0.0%)
3
(50.0%)
3
(50.0%)
6
(100.0%)
Total 28
(28.0%)
27
(27.0%)
45
(45.0%)
100
(100.0%)
included HPV 31, 33, 35, 39,45,51,52,56,58,59,66,67 and
68 shown in Table 3. Our results regarding HPV types were
similar to a study done by Gupta et al. which shows HPV
16(60.4%).8 In agreement with our study, a study done by
Shakya S et al. revealed (60.4%) HPV 16 and 12.5% were
other high-risk HPV genotypes (18,45,59). 14 In contrast to
this study, Ardhaoui M, et al. 15 showed that HPV 31 (1%),
HPV 16 (0.9%), HPV 59 (0.7%) were the most prevalent
genotypes.
Out of 100 cases in our study, total 28 cases were HPV
16. Among those 28 cases, 16(57.1%) shows ASCUS,
4(14.3%) shows LSIL, 3(10.7%) shows HSIL and least
common was SCC with single cases. Only 4 (14.3%) out
of 26 cases show negative for intraepithelial neoplasms on
LBC. The association between HPV16 and these cytological
abnormalities were statistically signicant with a p-value of
0.017, indicating a strong correlation.
Out of 100 cases in our study, total 27 cases were HPV 18.
Among those 27 cases, 10(37.0%) shows ASCUS, 8(29.6%)
cases shows LSIL, 2(7.4%) shows HSIL and 7(25.9%) cases
shows negative for cervical neoplasms in LBC ndings. The
relationship between HPV18 and the observed cytological
outcomes were not statistically signicant, with a p-value of
0.118.
Out of 100 cases in our study, total 45 cases were HPV
other high risk. Among those 45 cases 7 (15.6%) shows
ASCUS, 4 (8.9%) shows LSIL, 2(4.4%) cases shows HSIL and
32(71.1%) cases shows negative for cervical neoplasms in
LBC ndings. The association between HPV types other than
16 and 18 and cytological outcomes were highly signicant,
with a p-value of less than 0.0001.
Similar results were seen in studies done by HAQ NAWAZ
F, et al 16, Chaudhary RD et al 17, G Yeoh GP, et al.18 and
Bodal VK, et al.19 . In these studies, most common abnormal
Pap smear nding was also ASCUS accounting for 47.08%,
50.0 % , 65.9 % and 25.67 % respectively. Whereas in studies
by Jyothi R et al.20, BA.Jones et al.21, Vidhyadhar S et al.22,
Verma I, et al.23, RC L, et al.24, Meenai FJ et al.25 and K
Bhavani et al,26 most common epithelial cell abnormality was
LSIL accounting for 45 %, 48.93%, 60%, 62.5%, 38.88%, 41.7%,
28.16%, 47.22%, 49.43%, 33.92% and 44.26% respectively
among all pre invasive and invasive cases.

53 NMMJ | Volume 5 | Number 2 | July-December 2024
Nepal Mediciti Medical Journal
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was found between HPV-DNA test and positive cytology by a
study done by Kussaibi H.et al. 30
We analyzed the HPV DNA test and Liquid based cytology
(Figure 2)and out of 100 positive cases of HPV high risk
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lesion on LBC ndings and 43.0% cases show negative for
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HPV can cause visible changes in the cervical cells but these
changes may not be apparent in microscopic examination.
Macios A, et al..33 revealed there may be an absence of
cervical cancer precursors lesions on the cervix at the time of
sampling also the location may be deep in endocervical canal
or under mucosa which impedes proper sampling. Delpero
E, et al.34 revealed that current screening approaches
acknowledge that LBC smear has high specicity (96.8%)
but a low sensitivity (55.4%) which means that LBC smear
screening may produce false-negative result.
Finally, in context of Nepal there are still many barriers
present in cervical cancer screening one of the major
problems are lack of clinical and laboratory setup as HPV
detection by molecular method requires skill manpower,
a well-established molecular lab. Due to this problem the
overall cervical cancer screening in our country still relies
on Pap smear. Whereas various countries around the world
have started to introduce co-testing (HPV DNA test and
Pap smear) as the primary screening tool. Therefore, one of
the reason for this study was also to help understand and
highlight the importance of HPV DNA testing as a parallel
cervical screening tool with Pap smear.
Major strength of our present study included a large sample,
the use of a standardized and well validated HPV DNA test.
CONCLUSION
This study shows the prevalence of HPV is higher in middle
to young age group. ASCUS was common nding in LBC in
HPV positive cases followed by LSIL,HSIL and SCC. However
43% of HPV positive cases were reported as negative for
intraepithelial lesion (NILM) as there was no abnormality in
squamous epithelial cells. Both the HPV test and cervical
LBC smears are valuable tools for early detection of cervical
precursor lesion. However, neither test alone provides
conclusive results for comprehensive screening. So, it is
recommended to use both test in combination for more
accurate and reliable ndings in cervical cancer screening.

54
NMMJ | Volume 5 | Number 2 | July-December 2024
Retrospective study of correlation between high risk detection of HPV | Original Article
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