Radiation-Induced Colo-rectal Carcinoma -- A Report of Seven Cases --

Seven cases of colo-rectal carcinoma which were considered tohave developed secondarily to radiation injuries are reported.The incidence in our series was 0.8% (seven out of 880 primarycolo-rectal carcinomas). Initial diseases, the targets of radiotherapy,were five carcinomas of the uterine cervix, one of the cecum,and one of the vulva. The latent period, the interval between the initiation of irradiationand the detection of colo-rectal carcinoma, varied from 16 to21 years with an average of 18 years. Late radiation injuries were confirmed histologically in thesegments of the resected bowel involved in all cases. Postoperativecomplications were highly related to the radiation injuriesof the urinary bladder, macrohematuria in two and vesical fistulain three. Among the seven patients, four died within five years and threemonths, two of postoperative complications and two of recurrenceof the disease; the other three are alive and well without evidenceof disease, for three years and seven months, three years andthree months, and 11 months, respectively.