Performance of an artificial intelligence-based tool for cervical precancer screening in five countries in Africa: a prospective, observational, diagnostic accuracy study
Cervical cancer kills 300 000 women annually, almost entirely in low-income and middle-income countries. Visual inspection of the cervix using acetic acid (VIA) remains a common method of screening but has suboptimal accuracy. Automated visual evaluation (AVE) is an internally validated artificial intelligence (AI)-based tool designed to assist health workers to improve VIA and to aid diagnostic accuracy. We aimed to measure sensitivity and specificity of AVE for detection of histology-confirmed cervical intraepithelial neoplasia 2 or greater (CIN2 +) in real-world clinical settings, including testing its performance relative to naked-eye VIA. This prospective diagnostic accuracy study took place in government health facilities in Malawi, Rwanda, Senegal, Zambia, and Zimbabwe convenience-sampled between March 17, 2022, and Jan 13, 2023. Eligible participants were women attending routine cervical screening. Women who were pregnant; less than 6 weeks postpartum; had a previous hysterectomy or removal of the cervix; previous treatment for cervical precancer or cancer; and impaired visualisation of the cervix due to inflammatory changes associated with acute infection were excluded. Participants formed a consecutive series. The index test was the previously validated AI-based AVE system. The reference test was histopathology assessment of cervical tissue sample. Among 24 447 eligible women, 9559 (39·1%) were women living with HIV and 11 635 (47·6%) women were positive on at least one test: 7695 (31·5%) on HPV, 5610 on AVE (22·9%), and 2314 (9·6%) on VIA. Of 18 086 women with confirmed final status, 526 (2·9%) had CIN2 +. AVE was found to have sensitivity of 60·1% (95% CI 55·5-64·5) for CIN2 + and specificity of 81·9% (81·3-82·5) for less than CIN2. VIA was found to have sensitivity of 36·6% (32·2-41·1) and specificity of 94·2% (93·8-94·5). Improved sensitivity of AVE over VIA was statistically significant (p<0·0001). AVE-assisted VIA, considering a participant positive when either VIA or AVE is positive, was found to have sensitivity of 71·8% (67·6-75·8) and specificity of 79·0% (78·3-79·6). HPV sensitivity was 90·4% (87·4-92·9) and specificity was 80·1% (79·5-80·7). AVE showed increased sensitivity compared to VIA, with moderate loss in specificity. This method could potentially increase detection of cervical precancerous lesions. High HPV and CIN2 + positivity, influenced by high HIV positivity among participants, underscore the importance of scaling up population-based screening programmes in resource-limited settings to support cervical cancer elimination. Unitaid and Global Health Labs.