Human Papillomavirus Genotype Distribution Among Women with and Without Cervical Cancer: Implication for Vaccination and Screening in Ghana

Introduction: Determining the high-risk human papillomavirus (HR-HPV) genotypes burden in women with and without cervical cancer afford a direct comparison of their relative distributions. This quest is fundamental to implementing a future population-based cervical cancer prevention strategy in Ghana. We estimated the cervical cancer risk by HPV genotypes, and the HPV vaccine-preventable proportion of cervical cancer diagnosed in Ghana.

Materials And Methods: An unmatched case-control study was conducted at the two largest cervical cancer treatment centres in Ghana from 1st October 2014 to 31st May 2015. Cases were women diagnosed with cervical cancer and controls were women without cervical cancer who were seeking care at the two hospitals. Nested multiplex polymerase chain reaction (NM-PCR) was used to detect HPV infection in cervical samples. Logistic regression was used to determine the association between the risk of cervical cancer and identified HPV infection. P ≤0.05 was considered statistically significant.

Results: HPV deoxyribonucleic acid (DNA) data were analysed for 177 women with cervical cancer (cases) and 201 without cancer (controls). Cervical cancer was diagnosed at older ages compared to the age at which controls were recruited (median ages, 57 years vs 34 years; p < 0.001). Most women with cervical cancer were more likely to be single with no formal education, unemployed and less likely to live in metropolitan areas compared to women without cervical cancer (all p-value <0.001). HPV DNA was detected in more women with cervical cancer compared to those without cervical cancer (84.8% vs 45.8%). HR-HPV genotypes 16, 18, 45, 35 and 52 were the most common among women with cervical cancer, while 66, 52, 35, 43 and 31 were frequently detected in those without cancer. HPV 66 and 35 were the most dominant non-vaccine genotypes; HPV 66 was more prevalent among women with cervical cancer and HPV 35 in those without cervical cancer. Cervical cancer risk was associated with a positive HPV test (Adjusted OR (AOR): 5.78; 95% CI: 2.92-11.42), infection with any of the HR-HPV genotypes (AOR: 5.56; 95% CI: 3.27-13.16) or multiple HPV infections (AOR: 9.57 95% CI 4.06-22.56).

Conclusion: Women with cervical cancer in Ghana have HPV infection with multiple genotypes, including some non-vaccine genotypes, with an estimated cervical cancer risk of about six- to ten-fold in the presence of a positive HPV test. HPV DNA tests and multivalent vaccine targeted at HPV 16, 18, 45 and 35 genotypes will be essential in Ghana's cervical cancer control programme. Large population-based studies are required in countries where cervical cancer is most prevalent to determine non-vaccine HPV genotypes which should be considered for the next-generation HPV vaccines.