PREVALENCE OF HIGH RISK HUMAN PAPILLOMAVIRUS IN CERVICAL CANCER SPECIMENS AT THE UNIVERSITY OF CALABAR TEACHING HOSPITAL, CALABAR: HISTOPATHOLOGICAL AND MOLECULAR ANALYSIS (2009 – 2014)

Abstract

BACKGROUND: Cervical cancer is a significant health challenge in sub Saharan Africa. It
is the second commonest cancer in women worldwide and the commonest gynaecological
malignancy. Human papillomavirus (HPV) especially the high risk genotype which are
mostly transmitted sexually are the major aetiologic agent that has been implicated in this
disease. HPV DNA has been identified in 90 – 100% of cervical cancer specimen compared
to 5 – 20% of cervical specimen from epidemiological control group.
METHODOLOGY: Paraffin embedded tissue block of invasive cervical cancer specimen
from the study period (1st January, 2009 to 31st December 2014) were collected. Basic socio
demographic data were obtained from medical records in the department ( such as, surgical
pathology register, histopathology request forms). Sections of the tissue were obtained from
the blocks. A polymerase chain reaction, DNA enzyme immuno-assay and reverse
hybridization line probe assay was performed for HPV DNA detection and genotyping in the
specimen.
RESULTS: One hundred and twenty three cervical cancer specimens were analysed
representing 1.48% of the total samples received in the department of pathology, University
Of Calabar Teaching Hospital, Calabar during the study period (eight thousand three hundred
and eleven). There were one hundred and ninety-six gynaecological malignancy specimens
received giving an invasive cervical cancer prevalence of 62.7% among the gynaecological
malignancies in the centre. The specimens from female subjects aged from 32 to 75 years
were involved in this study. Their mean age was 48.59 ± 10.61. Majority 86(69.9%) of the
subjects were aged below 52 years. The peak age of the disease is 42 – 51years.Squamous
cell carcinoma constituted 97.56% of cases while adenocarcinoma constituted 2.44% of all
the cases. The commonest type amidst the subtypes of squamous cell carcinoma was non
keratinizing squamous cell carcinoma with a prevalence of 64.2%.
One hundred and thirteen (91.90%) of these samples were HPV DNA positive. The HPV
genotype isolated were high risk HPV genotype. Seven High Risk HPV (hrHPV) genotypes
were isolated from these specimens including types 16, 18, 31, 33, 35, 59 and 68/73.
The prevalence of HPV DNA in the samples by age group distribution shows the highest
prevalence of 38.6% from the 42-51 years age group. The prevalence of HPV genotype in
invasive cervical carcinoma among study samples show type 16 has the highest prevalence of
31.90%, followed by type 31 (30.09%), type 18 (15.40. Multiple infections represented
4.10% of all the HPV DNA positive samples
CONCLUSION: This study has been able to provide the pattern of high risk HPV infection in
invasive cervical cancer at the University of Calabar Teaching Hospital, Calabar. This can
serve as a basis for future study on the HPV DNA and genotype involved in the aetiology of
cervical cancer in other regions of the country. The knowledge of the prevalent high risk
HPV in cervical cancer in our environment would enable the development of a more effective
vaccine against high risk HPV involved in the aetiology of cervical cancer in our
environment.