The mexican cervical cancer screening trial: Self-sampling for human papillomavirus with unaided visual inspection as a secondary screen

The Mexican Cervical Cancer Screening (MECCS) study took place in the State of Michoacán. Primary screening was by self-sampling for high-risk human papillomavirus (HR-HPV). The objectives were to increase the specificity of primary HPV screening by requiring 2 positive HPV tests 1 year apart in women whose secondary screen was negative according to an acetic acidYaided visual inspection (VIA). In addition, we postulated that the sensitivity of VIAwould be sufficient to identify large preinvasive lesions and cancers unsuitable for cryotherapy if applied in a see-and-treat algorithm. A total of 8621 women (aged 30-50 years) were screened, and 14.3% were positive for HR-HPV. In phase 1, 11.9% of the HPV-positive women were VIA-positive and were referred for colposcopy with directed and random biopsies. If VIA-negative, women repeated the self-sample 1 year later to detect persistent HR-HPV (25.2% were positive). If persistently HR-HPVYpositive in phase 2, patients again had VIA, then all women (both VIA-positive and -negative) received directed and random biopsies. If cryotherapy had been used to treat HPV- and VIA-positivewomen in phase 1 or persistent HR-HPVYpositive (phase 2), the potential risk of undertreatment would have been 4.1%, and 66.4% of the treated patients would have had normal or cervical intraepithelial neoplasia I on biopsy. The VIA triage would refer 0.73% of the patients to colposcopy owing to the lesion size, location, or the presence of a cancer. On the basis of this pilot study, we are encouraged to explore and evaluate a rapid, more sensitive, and more specific self-test.