High-risk HPV serotype distribution in cervical cancer: comparative analysis of detection in cervicovaginal secretions and tissue DNA extraction.

Background: Cervical cancer is the most common gynaecological cancer. Molecular, clinical and epidemiological studies have shown that high-risk human papillomavirus (HPV) infection plays a causal role in the aetiopathogenesis of cervical carcinoma. This study is to determine the serotype distribution of high-risk HPV deoxyribonucleic acid (DNA) in women with established cervical cancer and compare HPV DNA detected in cervicovaginal secretions with that extracted from formalin-fixed paraffin-embedded tissue (FFPE) section in Lagos State University Teaching Hospital, Southwest, Nigeria. Methods: This was a comparative study involving subjects with clinical suspicion of cervical cancer. They had examination under anaesthesia, staging and biopsy done, and 44 of the subjects with histologically confirmed cervical cancer were recruited. Their cervico-vaginal secretion samples were taken for high-risk HPV and compared same with high-risk HPV obtained from tissue extraction. The result obtained was analysed using SPSS version 27. Result: Of 44 subjects with tissue diagnosis of cervical cancer, high risk (hr) - HPV DNA was detected in 38 (86.4%) in both cervicovaginal secretions and the FFPE tissues of the subjects. Of the hr-HPV detected from the FFPE samples, HPV 16 was seen in 27 (61.4%) and HPV 18 in 16 (36.3%) subjects. Other HPV types identified include 45 in 7 (15.9%), HPV 58 in 5 (11.4%), HPV 51 in 3(6.8%), HPV 39 in 2 (4.5%), HPV 66 in 1 (2.3%) and HPV 73 in 1 (2.3%) of cases. There were 16 (36.4%) of single and 22 (50.0%) multiple serotypes of hr-HPV detected. Of the multiple serotypes, two serotypes in 21 (47.3%) cases and three serotypes (16, 18 and 58) in 1 (2.3%) case.The test kit detected the same number of hr-HPV as in tissue extraction (86.4%); however, with different serotypes. With tissue extraction more (serotypes) HPV 16 and 18 were detected compared to the use of cervicovaginal secretion (p = 0.001) and (p = 0.046).The commonest histological type of cervical cancer found among the subjects was squamous cell carcinoma (SCC) 38 (86.4%) and adenocarcinoma 4 (9.2%). Thirty-three subjects (86.8%) of those with SCC were positive for hr-HPV with serotypes 16 and 18, predominating. Conclusion: The hr-HPV DNA detection rate on cervicovaginal secretion using the test kit is similar to that of tissue extraction FFPE, with serotypes 16 and 18 being predominant. This finding further confirms the reliability of the use of the HPV test kit on cervicovaginal secretion as a screening tool for premalignant and malignant lesions of the cervix.