[Induction of malignancies by radiotherapy: a retrospective study of 454 tumors].

On the basis of 98 case reports compiled from the literature of the years 1902 to 1984, a retrospective study was conducted on 454 tumors developed after radiotherapy within the irradiation field. 226 patients (49.8%) were treated for a benign primary disease and 222 (49.6%) for a malignant primary disease. In six cases the primary diagnosis was unknown. The histologic investigation of the tumors showed sarcomas in 52% of the cases, carcinomas in 38%, and leukemias in 8.5%. Cerebral tumors were described in two cases. The average latency was 7.1 years in leukemia, 12.1 years in sarcomas, and 19 years in carcinomas. Carcinomas were preponderantly found after a focal dose up to 30 Gy, sarcomas after higher doses up to 70 Gy. In leukemia, a dose-effect correlation was not evident. The influence of surgery, chemotherapy, the age of the patients at the moment of radiotherapy, as well as the dignity of the primary disease on latency and histology of the radiogenic tumor was also investigated.