The risk of tumor induction in man following medical irradiation for malignant neoplasm.

A review of second malignant tumors (S.M.T.s.) following therapeutic irradiation formalignant neoplasm in man is presented. Twenty-one new cases are added to the literature, 3 of adenocarcinoma of the endometrium following treatment for squamous cell carcinoma of the cervix, 3 of adenocarcinoma of the large bowel following treatment for squamous cell carcinoma of the cervix, 9 S.M.T.s in irradiated oropharyngeal or oral mucosa, and 6 single cases of S.M.T.s following radiotherapy of cancers in other sites. It is suggested that there is relatively low incidence of S.M.T.s among patients formalignancy, but the risk remains to be established by an appropriate study of controland test populations.