Does human papilloma virus participate in colorectal carcinogenesis?

Colorectal cancer is one of the most commonly diagnosed neoplasms still associated with relatively high mortality. Viral infections are often mentioned among the neoplasm transformation risk factors. Incidence of human papilloma virus (HPV), associated with high oncogenic risk, in the large intestine and the meaning of its presence in the colorectal carcinogenesis are still not clear. The aim of the study was to show a presence of HPV in specimens of adenomatous polyps and colorectal cancer using the Q-PCR method. Fifty patients (32 M/18W, mean age 62.8 years) were enrolled in the study, for whom tissue samples were obtained. Study material involved paraffin blocks derived from samples collected by flexible sigmoidoscopy from 10 polyps and 10 large intestine adenocarcinomas and 30 paraffin blocks with specimens of surgically removed large intestine adenocarcinomas. Presence of HPV genome was confirmed by quantitative PCR method using commercially available Abbott RealTime High Risk HPV test. The test is able to detect 14 most prevalent high oncogenic risk subtypes of human papilloma virus. Status of HPV DNA was successfully assessed in all 50 samples. No HPV DNA was discovered in any of the tested samples. Presence of high oncogenic risk HPV subtypes in large intestine adenoma and adenocarcinoma seems to be very rare, and its dominating role in the pathogenesis of colorectal cancer, even if possible, is unlikely.