Anal cancer is thought to share similarities with cervical cancer. American Cancer Society (ACS) estimates about 8200 new cases of anal cancer in the United States. Anal cancer risk is greater among those who are infected with Human Papillomavirus (HPV), those who have a compromised immune system (HIV/AIDS), smokers, those who have multiple sexual partners and have receptive anal intercourse, and women who have had cervical cancer/vulvar cancer. There is a slightly higher risk of anal cancer in women compared to men. Individuals living with HIV are 28 times more likely than the general population to be diagnosed with anal cancer and have poorer survival rates. Among all individuals, men who have sex with men (MSM) are at increased risk, and the risk doubles with having HIV infection.
Like many other cancers, stage or severity of the cancer at diagnosis is important in treatment and survival. For instance, five-year survival is 78% when diagnosis is made at an early stage (local disease). Screening for anal cancer may help early detection and improve outcomes related to anal cancer. Although some practitioners are using routine anal cancer screening using pap smear screening method, there are no randomized control trials (RCT) to evaluate improved survival with anal pap smear screening. The “Anchors study” is an ongoing RCT to evaluate best ways of anal cancer prevention among individuals living with HIV. Information about the study and recruitment details can be found in the following link: https://anchorstudy.org/.
ASC website states that some experts recommend anal cancer screening to be conducted by anyone with a history of anal warts, and that the test be conducted every year for HIV positive MSM and every 2-3 years for MSM without HIV infection. More information about the recommendations can be found here: https://www.cancer.org/cancer/anal-cancer/causes-risks-prevention/risk-factors.html. US Department of Veterans affairs (VA) recommend all at-risk men and women to be screened for anal cancer at baseline and annually thereafter using the digital rectal examination (DRE) or anal pap-smear. Detailed recommendations and statistics about anal cancer screening can be found in the VA primary care manual in the following link: https://www.hiv.va.gov/provider/manual-primary-care/anal-dysplasia.asp , articles: http://nccc.ucsf.edu/2017/01/06/case-of-the-month-review-of-anal-cancer-screening-for-hiv-positive-patients/ and http://online.liebertpub.com/doi/full/10.1089/apc.2013.0358.