Radiation-induced cancer in maxillofacial region

We reported here on two cases of radiation-induced cancer developed in the oral and maxillofacial region. Two cases were as follows: Case I: In 1951, 23-year old man was irradiated externally for treatment of actinomycosis in the right mandible. In 1978, 27 years later, the man was admitted to our hospital for squamous cell carcinoma in the right buccal mucosa. Case II: In 1974, 64-year old man was treated by external radiation therapy following chemotherapy for tongue cancer of the right side. In 1988, 14 years later, the squamous cell carcinoma in the labial mucosa of the left side developed. In both cases, the cancers developed in the previous irradiated area. As in the primary malignant case there were some difficulties in distinguishing radiation-induced cancer from late recurrence, was used diagnostic criteria of radiation-induced cancer by Satoh's and Sakai's. The detailed relationship between irradiation dose and carcinogenesis was unknown. It is important that the evaluation of irradiation effect and the risk of carcinogenesis be established. (author)