Background: WHO recently advocated a sequential testing with HPV testing followed by VIA as a suitable option for cervical cancer screening. However, its accuracy has not been directly assessed in the context of primary screening
Aim: To evaluate the effectiveness of HPV-testing (self-HPV) followed by VIA for cervical cancer screening in a low-income setting
Methods: We recruited 540 women aged between 30 and 65 years in Cameroon. Eligible women were counseled about HPV infection, cervical cancer and how to perform self-HPV. HPV positive women and a randomly chosen sample of HPV negative women were called back for VIA examination and biopsies. Disease was defined by presence of cervical intraepithelial neoplasia grade 2 or worse (CIN2+). Tests qualities of VIA, HPV testing and sequential testing were determined
Results: HPV prevalence was 27.0% (95% CI: 23.5%-30.9%). VIA was positive in 15.1% (16/106) of HPV positive and 6.8% (7/102) of HPV negative women. CIN 2 or 3 were found in 4.1% (9/217) and carcinoma in 0.9% (2/217) of women. Sensitivity and specificity of VIA for CIN2+ were 36.4% (95% IC: 15.2%-64.6%) and 90.4% (95% CI: 85.4%-93.7%), respectively. Sensitivity of self-HPV (100.0% (95% CI: 79.6%-100.0%) to detect CIN2+ was 66% higher than that of the sequential testing (33.3% (95% CI: 15.2%-58.3%)). Meantime, specificity of HPV testing (74.5% (95% CI: 70.6%-78.1%)) was 22% lower than that of sequential testing (96.7% (95% CI: 94.8%-97.9%)). Positive predictive value (PPV) was two times higher for sequential testing (22.7% (95% CI: 10.1%-43.4%) than for HPV testing only (10.3% (95% CI: 6.3%-16.3%))
Conclusions: HPV testing followed by VIA improves the specificity of cervical cancer screening, but at the cost of an important loss of sensitivity. Ways to ameliorate VIA performance or other triage tools are needed to increase positive predictive value of a HPV-based screening strategy without impairing its sensitivity