Carcinoma of the Rectum following Irradiation of Carcinoma of the Cervix

Three case histories are presented relating development of rectal cancer 20 yr after combined Ra and x-ray treatment of cancer of the uterine cervix. Radiation doses received by the three patients (Ra + x rays) were: 8687 mghr + 2400 r, 4900 mg-hr + 4000 r, and 8100 mg-hr + 1220 r. The rectal tumors were first observed 19, 12, and 20 yr after radiotherapy. It was relatively easy to differentiate between the second primary tumor and a late recurrence of the original tumor. In all three cases, the initial tumor was a squamous cell carcinoma and the subsequent one an adenocarcinoma. Histologically, these are separate primary tumors. Perirectal induration was noted in the patients, and in two it was thought to be due to extension of the carcinoma. Todd previously described the perirectal induration as the extrinsic reaction. Evidence of early damage by irradiation was shown by the development of a stricture in Case 1 and a vesicovaginal fistula in Case 3. It is difficult to be certain that these rectal tumors are related to irradiation and did not occur by coincidence. (BBB)