Screening colonoscopy for the detection of neoplastic lesions in asymptomatic HIV-infected subjects

Background: Although non-AIDS defining malignancies are rapidly increasing as HIV-infected subjects live longer, little is know about the results of screening for colonic neoplasms (adenomatous polyps and adenocarcinomas) in this population. Methods: We conducted a screening colonoscopy study to determine the prevalence of colonic neoplasms in 136 asymptomatic HIV-infected subjects ≥50 years of age and 272 asymptomatic uninfected control subjects matched for age, sex, and family history of colorectal cancer. Advanced neoplasms were defined as adenomas ≥10 mm or any adenoma, regardless of size, with villous histology, high-grade dysplasia, or adenocarcinoma. Results: The prevalence of neoplastic lesions was significantly higher in HIV-infected subjects than in control subjects (62.5% vs 41.2%, p<0.001), and remained highly significant after adjustment for potential confounding variables (odds ratio =3.00; 95% confidence interval, 1.83 to 4.93). Among patients with colorectal adenocarcinoma, HIV-infected subjects were significantly younger (52.4 (SD 1.3) vs 60.3 (SD 4.0) years, p=0.002) and were more likely to have advanced cancers (stage III or IV) than control subjects (60.0% vs 16.7%, p=0.24). Of HIV-infected subjects with advanced neoplasms proximal to the splenic flexure, distal neoplastic lesions were absent in 88.9% of individuals and these would have been missed by flexible sigmoidoscopy. Conclusions: HIV-infected subjects have a higher prevalence of colonic neoplasms, and adenocarcinomas develop at a younger age and are more advanced than in uninfected subjects. Our findings suggest that screening colonoscopy should be offered to HIV-infected subjects, but the age of initiation and the optimal frequency of screening require further study.