Accuracy of screening tests for cervical pre-cancer in women living with HIV in low-resource settings: a paired prospective study in Lusaka, Zambia.

INTRODUCTION

To provide evidence to improve cervical screening for women living with HIV (WLHIV), we assessed the accuracy of screening tests that can be used in low-resource settings and give results at the same visit.

METHODS

We conducted a paired, prospective study among consecutive eligible WLHIV, aged 18-65 years, receiving cervical cancer screening at one hospital in Lusaka, Zambia. The histopathological reference standard was multiple biopsies taken at two time points. The target condition was high-grade cervical intraepithelial neoplasia (CIN2+). The index tests were high-risk human papillomavirus detection (hrHPV, Xpert HPV, Cepheid), portable colposcopy (Gynocular, Gynius), and visual inspection with acetic acid (VIA). Accuracy of stand-alone and test combinations were calculated as the point estimate with 95% confidence intervals. A sensitivity analysis considered disease when only visible lesions were biopsied.

RESULTS

Among 371 participants with histopathological results, 27% (101/371) women had CIN2+ and 23% (23/101) was not detected by any index test. Sensitivity and specificity for stand-alone tests were: hrHPV, 67.3% (95% CI: 57.7-75.7) and 65.3% (59.4-70.7); Gynocular 51.5% (41.9-61.0) and 80.0% (74.8-84.3); and VIA 22.8% (15.7-31.9) and 92.6% (88.8-95.2), respectively. The combination of hrHPV testing followed by Gynocular had the best balance of sensitivity (42.6% [33.4-52.3]) and specificity (89.6% [85.3-92.7]). All test accuracies improved in sensitivity analysis.

CONCLUSION

The low accuracy of screening tests assessed might be explained by our reference standard, which reduced verification and misclassification biases. Better screening strategies for WLHIV in low-resource settings are urgently needed.

REGISTRATION NUMBER

The trial was registered prospectively at ClinicalTrials.gov (ref: NCT03931083 ). The study protocol has been previously published, and the statistical analysis plan can be accessed on ClinicalTrials.gov .

KEY MESSAGES

The 2021 World Health Organization guidelines recommend that women living with HIV (WLHIV) receive screening for high risk human papillomavirus high-risk human papillomavirus (hrHPV) genotypes at three- to five-year intervals, followed by a triage test to determine whether treatment is needed but this is based on low and moderate certainty evidence. This study among WLHIV in Lusaka, Zambia evaluated three screening tests that allow same-day treatment; hrHPV test, portable colposcopy (Gynocular), and visual inspection with acetic acid (VIA), using strict methods to reduce verification and misclassification biases. The test accuracy of the different screening was poor, with sensitivities and specificity for stand-alone tests: hrHPV, 67.3% and 65.3%; Gynocular 51.5% and 80.0%; and VIA 22.8% and 92.6%; respectively. Our findings have implications for research and cervical cancer screening policies among WLHIV if test-accuracy in this high-risk population has been overestimated from a majority of exsisting studies that are affected by verification and misclassification biases. Methodologically robust studies are crucial to inform cervical cancer screening practices and policies for the successful implementation of a cervical cancer elimination plan in sub-Saharan Africa, where 85% of women with cervical cancer and HIV live.