Accuracy of concurrent visual and cytology screening in detecting cervical cancer precursors in rural India

The high burden of cervical cancer and inadequate/suboptimal cytology screening in developing countries led to the evaluation of visual screening tests, like visual inspection with acetic acid (VIA) and Lugol's iodine (VILI). We describe the performance of VIA, VILI and cytology, carried out in a multinational project called "Screening Technologies to Advance Rapid Testing" in 5,519 women aged 30-49 years, in detecting cervical intraepithelial neoplasia (CIN). VIA, VILI and cytology were positive in 16.9%, 15.6% and 6.1% women, respectively. We found 57 cases of CIN2, 55 of CIN3 and 12 of cervical cancer; 90% of CIN3 and 43% CIN2 cases were positive for p16 overexpression and high-risk HPV infection, indicating a high validity of histological diagnosis. The sensitivity of VIA, VILI and cytology to detect high-grade CIN were 64.5%, 64.5% and 67.7%, respectively; specificities were 84.2%, 85.5% and 95.4%. A high proportion of p16 positive CIN 3 (93.8%) and 2 (76.9%) were positive on cytology compared with visual tests (68.8% and 53.8%, respectively) indicating a higher sensitivity of cytology to detect p16 positive high-grade CIN. However, the immediate availability of the results from the visual tests permits diagnosis and/or treatment to be performed in the same sitting, which can potentially reduce loss to follow-up when women must be recalled following positive cytology. Organizing visual screening services in low-resource countries may facilitate the gradual building of an infrastructure committed to screening allowing the eventual introduction of more sensitive, highly objective, reproducible and affordable human papillomavirus screening tests in future.