High-risk human papillomavirus genotyping in cervical cancers in Tanzania

High-risk human papillomavirus (hrHPV) infection causes almost all cervical cancer. Women living with human immunodeficiency virus (Women living with HIV: WLWHIV) are at a six-fold increased risk of developing cervical cancer. This study assessed hrHPV types in cervical cancer by HIV status and histologic subtypes at Muhimbili National Hospital (MNH) in Tanzania.

This cross-sectional study used formalin-fixed paraffin-embedded (FFPE) archived tissue blocks of cervical carcinomas diagnosed in the Department of Anatomical Pathology at MNH from January to December 2020. Tissue sections were tested for 15 HPV genotypes (16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, and 68) using the Ampfire assay. The distribution of HPV genotypes was assessed and compared by HIV status and histologic subtypes.

The mean age ± standard deviation (N = 227, with valid HPV results) was 55 ± 12.9 years, 28.6% (n = 65) were WLWHIV, and squamous cell carcinoma (SCC) was the most common histologic subtype (91.2%). Most cervical carcinomas (81.1%, n = 184) tested positive for hrHPV with HPV16 (44.1%), HPV18 (15.9%), HPV35 (8.4%) and HPV45 (5.7%) being the most common HPV types. hrHPV was higher among older women with 64.5%, 85.1% and 81.3% among 30-40, 41-60 and ≥ 61-year-old women, respectively (p = 0.033). HPV16 was more commonly detected in SCC (47.8%) than in adenocarcinomas (5%) (p < 0.0001). There was no difference in hrHPV positivity by HIV status.

We found a high proportion of hrHPV among cervical carcinomas diagnosed in Tanzania. Rolling out HPV vaccines that target more hrHPV types than HPV16/18, especially HPV35 and HPV45, could optimize protection against cervical cancer in Tanzania.