Hotspots of Anal Cancer Screening in a High-risk Population: A Clinical Study on Free Provision, Best Method, Self-sampling, and Independent Risk Factors.

Abstract

Background/aim: As of 2024, anal cancer (AC) has been steadily increasing worldwide but, due to insufficient evidence, anal cancer screening (ACS) has yet to be standardized. Furthermore, most high-risk people in the world have no help paying for it. Therefore, our primary endpoint was to assess the best screening method for these subjects through a provision that was free of charge (all costs were covered by the Italian public health service). Awareness-raising campaign, determination of risk factors, education on anal self-examination, and sampling (ASS) were secondary objectives.

Patients and methods: Screening was on a voluntary basis. Engaging in receptive anal intercourse and having a history of cervical dysplasia were the main inclusion criteria. Level 1 ACS tools included digital ano-rectal examination, anoscopy, anal Pap, and anal human papillomavirus (HPV) DNA test (both through self- and proctologist- sampling); high-resolution anoscopy (HRA) with (HRAB) or without biopsy comprised level 2 screening. High-risk people were enrolled until the available funds were exhausted.

Results: Fifty high-risk people (40 men who had sex with men -MSM-, 9 women, and 1 heterosexual man) were enrolled. AC was found in one HIV-seropositive MSM, high-grade squamous intraepithelial lesion in 10 (20%) MSM, low-grade squamous intraepithelial lesion LSIL in 13 cases (12 MSM and 1 woman). The combination of HRAB and Pap smear screening achieved the highest values for sensitivity, specificity, and accuracy. ASS HPV DNA test provided excellent results comparable to clinician retrieval. Overweight and college education were identified as independent factors for the risk of and prevention of AC, respectively.

Conclusion: A free ACS not only appears justified but also recommended to people screened for AC. Excess weight represents a further risk for this population.