Home-based self-sampling vs clinician sampling for anal precancer screening: The Prevent Anal Cancer Self-Swab Study

Abstract

Sexual minority men are at increased risk for anal squamous cell carcinoma. Our objective was to compare screening engagement among individuals randomized to self-collect an anal canal specimen at home or to attend a clinic appointment. Specimen adequacy was then assessed for human papillomavirus (HPV) DNA genotyping. A randomized trial recruited cisgendered sexual minority men and transgender people in the community and assigned them to use a home-based self-collection swabbing kit or attend a clinic-based swabbing. Swabs were sent for HPV genotyping. The proportions of participants completing screening in each study arm and the adequacy of their specimens for HPV genotyping were assessed. Relative risks were estimated for factors associated with screening. A total of 240 individuals were randomized. Age (median, 46 years) and HIV status (27.1% living with HIV) did not differ by study arm. A total of 89.2% and 74.2% of home-arm and clinic-arm individuals returned the swab, respectively (P = .003), difference between groups, 15.0% (95% CI 5.4%-24.6%). Among black individuals, 96.2% and 63.2% in the home and clinic arms screened (P = .006). Among individuals with HIV, 89.5% and 51.9% in the home and clinic arms screened (P < .001). Self-collected swabs and clinician-collected swabs were comparable in adequacy for HPV genotyping (96.3% and 93.3%, respectively). People at highest risk for anal cancer may be more likely to screen if they are able to self-collect swabs at home rather than attend a clinic.

Keywords: HIV; anal neoplasms; human papillomavirus DNA tests; self-testing; sexual and gender minorities.

Figure 1:

Trial Profile

Figure 2:

Proportion of participants who engaged in screening by study arm stratified by (A) race and ethnicity and (B) HIV status. “Other” race excluded due to sparse data (n=5).