Early outcomes of a high-resolution anoscopy-based anal cancer screening program among people with HIV enrolled in an integrated healthcare system

Few studies have examined outcomes of high-resolution anoscopy (HRA)-based screening for people with HIV infection (PWH), a population at increased risk for anal cancer. Large integrated health care system. Cohort study of 13,552 people with HIV infection, comparing incidences of anal cancer and advanced anal cancer (higher stage, recurrence, death, or surgical salvage) before and after HRA became available (2008). Calendar time was divided as 1998-2007, 2008-2010, and 2011-2012. Rate ratios (RRs) were obtained from Poisson regression models with adjustment for baseline demographic and health variables. Cohort cases during 2008-2012 were included in a nested case-control study, evaluating association of screening with anal cancer (33 cases, 330 controls) and advanced anal cancer (19 cases, 190 controls). Odds ratios (ORs) for receipt of screening were obtained from conditional logistic regression models with adjustment for baseline demographic and health history variables. Compared with 1998-2007 (pre-HRA), 2008-2010 adjusted RRs were 1.32 [95% confidence intervals (CI): 0.77 to 2.27; P = 0.31] for anal cancer and 2.11 (95% CI: 0.99 to 4.48; P = 0.053) for advanced anal cancer; and 2011-2012 adjusted RRs were 0.35 (95% CI: 0.12 to 0.99; P = 0.048) for anal cancer and 0.23 (95% CI: 0.03 to 1.77; P = 0.16) for advanced anal cancer. Individual history of screening did not reach statistical significance for anal cancer (OR 1.7; 0.6-4.6) or advanced anal cancer (OR 0.44; 0.1-3.8). Despite the possible effect of secular trends, we found 2008-2012 incidence trends for anal cancer and advanced anal cancer that seem consistent with expected findings of a beneficial screening program.

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