Rectal carcinoma after radiotherapy for cervical carcinoma in patients with a family history of colorectal carcinoma: report of two cases.

Rectal carcinoma is a rare, but well documented late complication of pelvic irradiation. Little is known about the factors predisposing to the development of radiation-associated rectal carcinoma. We present two patients who developed rectal carcinoma 17 and 26 years after radiotherapy for carcinoma of the uterine cervix. In one patient, mutation in exon 4 of the hMLH1 gene was detected. Radiation-associated rectal carcinoma represents a rare late toxicity of radiotherapy for cervical carcinoma that may occur in patients with a family history of colorectal carcinoma, including hereditary non-polyposis colorectal cancer.