Carcinoma and synchronous hyperplastic polyps of the large bowel.

The prognostic and biological meaning of the association of colonic cancer with hyperplastic polyps (HP) is not as well known as that with adenomatous polyps (AP). In order to gain some insights into this matter, we have retrospectively studied two hundred and twelve patients with colon-rectal carcinoma in which 64 (30.18%) had synchronous AP, 24 (11.32%) had synchronous HP, 13 (6.13%) had both AP and HP and 111 had no synchronous polyps (52.36%). The 34 cases of synchronous HP, whether or not associated with AP, were located in the same colonic segments of the cancer and were found usually in the sigmoid-rectum. The AP were found throughout the colon-rectum with a similar rate of association with the cancer in each segment. The cancer associated with HP have a higher prevalence in the better prognostic stages of both Dukes and Jass-Morson systems. Conversely both AP and AP+HP associated cancers exhibit prevalences rates higher in the worst prognostic stages. Our observations suggest that separate factors might promote the growth of HP and AP and that a relationship between colonic cancer and synchronous HP might exist and differ from that demonstrated for AP and colonic cancer.