Cervical Cancer Screening of Postmenopausal Women in Low- and Middle-income Countries Using HPV Self-sampling and Triage by Genotyping and Cytology

Cervical cancer remains a leading cause of cancer-related mortality among women in low- and middle-income countries (LMICs), including Cameroon. Although most screening programs target women aged 30-49 years, approximately 40% of cervical cancer cases occur after the age of 50. Postmenopausal women face unique anatomical and physiological changes-particularly the regression of the squamocolumnar junction into the endocervical canal-that reduce the sensitivity of visual triage methods such as visual inspection with acetic acid (VIA). Evidence on optimal screening and triage strategies for women aged 50 years and older in LMIC settings is currently lacking.

This feasibility study aims to evaluate the diagnostic performance, acceptability, and clinical outcomes of a cervical cancer screening strategy based on high-risk human papillomavirus (hr-HPV) testing on self-collected vaginal samples, followed by cytology triage of HPV-positive postmenopausal women. The study also explores the added value of extended hr-HPV genotyping to refine risk stratification. The target population includes 500 women aged 50-65 years living in the Mifi Health District, West Cameroon.

At the first visit, eligible women will receive standardized information on cervical cancer and study procedures before providing written informed consent. Participants will then collect a self-obtained vaginal sample, which will be tested onsite using the GeneXpert platform for detection of all hr-HPV types. HPV-negative women will be advised to repeat screening after 5-10 years (or 3-5 years if HIV-positive). HPV-positive women will undergo clinician-collected Pap cytology and endocervical brushing (ECB). Cytology slides will be prepared using manual liquid-based cytology techniques, digitized using a portable whole-slide scanner, and interpreted remotely by trained cytopathologists. ECB samples will undergo histopathological evaluation and will constitute the diagnostic gold standard for assessing triage performance.

Women with cytology results ≥ASC-US will be referred for evaluation and treatment at Bafoussam Regional Hospital. A VIA/VILI examination will guide thermal ablation treatment using WHO-recommended devices and probes adapted to cervical anatomy. Cervical biopsies will be performed in the presence of suspicious lesions suggestive of high-grade disease or cancer. All treatments, follow-up assessments, and management of adverse events will be provided free of charge.

All HPV-positive participants, regardless of baseline cytology results, will be invited for a 12-month follow-up visit including repeat HPV testing, cytology, ECB, and VIA/VILI. Persistence of CIN2+ at 12 months will indicate the need for large loop excision of the transformation zone (LLETZ). Treatment adherence, side effects, and acceptability of the screening and treatment process will be assessed using structured questionnaires administered at baseline, post-treatment (4-6 weeks), and 12 months.

The primary outcomes include sensitivity, specificity, positive and negative predictive values, and likelihood ratios of cytology and extended genotyping (alone or combined) for detection of CIN2+ compared with ECB histology. Secondary outcomes include prevalence of hr-HPV infection and high-grade lesions, effectiveness of thermal ablation for CIN2+ clearance at 12 months, acceptability among women and healthcare providers, and adherence to all steps of the two-stage screening strategy.

This project is expected to generate essential evidence to guide cervical cancer screening policies for older women in LMICs, support the WHO global elimination initiative, and offer a scalable, context-adapted approach combining self-sampling, digital cytology, and appropriate treatment pathways.