Identification of human papillomaviruses from formalin-fixed, paraffin-embedded pre-cancer and invasive cervical cancer specimens in Zambia: a cross-sectional study

Abstract

BackgroundThe most common human papillomavirus (HPV) genotypes isolated from cervical cancer in select African countries are HPV-16, HPV-18, HPV-35, and HPV-45, but the most common genotypes in Zambia are unknown. The overall objective of this study was to assess the potential impact of current HPV vaccines in preventing cervical cancer in Zambia, by determining the combined prevalence of HPV-16 and/or HPV-18 in invasive cervical cancer (ICC) and high-grade pre-cancer [cervical intraepithelial neoplasia 2 or 3 (CIN2/3)] cases.FindingsWe compared DNA extraction techniques to determine which assay performs well in the Zambian context, where unbuffered formalin is used to fix specimens. We then tested specimens with the Abbott RealTime High-Risk HPV test to estimate the prevalence of HPV-16/18 in formalin-fixed, paraffin-embedded ICC and CIN2/3 specimens. DNA extraction using heat (without xylene) was more successful than xylene-based extraction. Over 80% of specimens tested using heat extraction and the Abbott RealTime HPV test were positive for HPV. HPV-16 and/or HPV-18 were identified in 65/93 (69.9%) ICC specimens positive for HPV and in 38/65 (58.5%) CIN2/3 specimens positive for HPV.ConclusionsTo our knowledge this is the first report to identify HPV genotypes in cervical cancers in Zambia. A combined HPV-16/18 prevalence of 69.9% in ICC specimens suggests that current vaccines will be highly protective against cervical cancer in Zambia.

Distribution of High-Risk Human Papillomavirus Genotypes in Precancerous Cervical Lesions in Ouagadougou, Burkina Faso

“…We found no significant link between the histological lesions and the HPV carrier. In our study, the prevalence rate of precancerous lesions was significantly lower than that of most studies [13] [15] [21]. This could be explained by the size of our sample but especially by the quality of our samples; or other factors other than HPV such as bacteria, parasites, fungi, other virus, or simply other HPV genotypes that our detection kit could not characterize.…”

“…Other studies have shown results that differ from ours [13]- [15]. In Zambia, a team [13] found a prevalence of moderate to severe dysplasia in 31% of the cases (65 HPV positive cases against 75 cases tested and 69 cases considered appropriate cases) (p < 0.001). However, this study in Zambia also used samples with similar storage period as ours and there was roughly the same number of samples.…”

A high prevalence of human papillomavirus 16 and 18 co-infections in cervical biopsies from southern Brazil

“…In the present study, HPV DNA was detected in 100% of the premalignant and malignant lesions that were present in the cervical biopsy specimens analyzed. This level of prevalence is similar to the levels reported by studies conducted in other countries that also examined paraffin-embedded samples graded as CIN I–III and cervical cancer: United States (95%), 13 Zambia (94%), 14 Ethiopia (93%), 15 and Pakistan (88%). 16 These findings reinforce the causal role of HPV infections in developing cervical malignancy 5 and the importance of archival biopsy samples as a source of material for studies related to the identification of HPV types.…”

The burden of cervical pre-cancer and cancer in HIV positive women in Zambia: a modeling study

“…The very large burden of cervical disease in HIV positive women reported here necessitates a multi-pronged prevention and control approach, including primary prevention with vaccination, secondary prevention with screening and treatment of precancerous lesions, and treatment of cervical cancers. This group has previously reported that approximately 70 % of cervical cancers at the University Teaching Hospital in Lusaka are positive for HPV-16 and/or HPV-18, the two HR-HPV genotypes in widely available vaccines [ 21 ]. In addition, immune responses to HPV vaccination among HIV positive women are reported to be generally robust [ 22 ].…”