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BACKGROUND: Anal cancer incidence has increased in Western countries in recent decades and currently there are no consensus screening guidelines. Home-based self-sampling kits might facilitate screening for anal precancer/cancer but could require travel through postal mail where they may experience extreme temperatures or long transport times. OBJECTIVE: To determine the effect of the environment on specimen adequacy for HPV genotyping of a mailed home-based self-sampling anal cancer screening kit. STUDY DESIGN: The Prevent Anal Cancer (PAC) Study in Milwaukee, Wisconsin recruited men who have sex with men (MSM) and transgender persons 25 years of age and older. Participants were randomized to receive a mailed self-sampling kit or attend a clinic for screening. Kits were insulated with foam and included a device to record temperature every twenty minutes. Samples were returned via mail and underwent HPV genotyping using the SPF(10)-LiPA(25) assay which also detected human RNase P to determine specimen adequacy by qPCR. For the first 93 kits, logistic regression assessed associations between specimen inadequacy and temperature, freeze-thaw cycle, presence of fecal matter, and number of days in an uncontrolled environment. RESULTS: Most specimens (92.5%) were adequate for HPV genotyping. Specimen inadequacy was not associated with temperature, freeze-thaw cycle, or transit time. Fecal matter was present more often in inadequate (71.4%) compared to adequate specimens (16.3%) (p = .004). CONCLUSIONS: These real-world data from mailed home-based anal self-sampling kits found that environmental conditions did not affect specimen adequacy. While over 90% of specimens were adequate, presence of fecal matter predicted specimen inadequacy.

IntroductionSquamous cell carcinoma of the anus is a common cancer among sexual minority men, especially HIV-positive sexual minority men; however, there is no evidenced-based national screening protocol for detection of anal precancers. Our objective is to determine compliance with annual anal canal self-sampling or clinician-sampling for human papillomavirus (HPV) DNA.Methods and analysisThis is a prospective, randomised, two-arm clinical study to evaluate compliance with annual home-based versus clinic-based HPV DNA screening of anal canal exfoliated cells. The setting is primary care community-based clinics. Recruitment is ongoing for 400 HIV-positive and HIV-negative sexual minority men and transgender persons, aged >25 years, English or Spanish speaking, no current use of anticoagulants other than nonsteroidal anti-inflammatory drugs and no prior diagnosis of anal cancer. Participants are randomised to either receive a swab in the mail for home-based collection of an anal canal specimen at 0 and 12 months (arm 1) or attend a clinic for clinician collection of an anal canal specimen at 0 and 12 months (arm 2). Persons will receive clinic-based Digital Anal Rectal Examinations and high-resolution anoscopy-directed biopsy to assess precancerous lesions, stratified by study arm. Anal exfoliated cells collected in the study are assessed for high-risk HPV persistence and host/viral methylation. The primary analysis will use the intention-to-treat principle to compare the proportion of those who comply with 0-month and 12-month sampling in the home-based and clinic-based arms. The a priori hypothesis is that a majority of persons will comply with annual screening with increased compliance among persons in the home-based arm versus clinic-based arm.Ethics and disseminationThe study has been approved by the Medical College of Wisconsin Human Protections Committee. Results will be disseminated to communities where recruitment occurred and through peer-reviewed literature and conferences.Trial registration numberNCT03489707.