Major complications of radiotherapy in cancer of the oral cavity and oropharynx. A 10 year retrospective study.

In an attempt to determine the late effects and associated morbidity of radiotherapy on normal tissue, patients with squamous carcinoma of the oral cavity and oropharynx were retrospectively reviewed. Between 1964 and 1975, 569 patients with cancer of the floor of the mouth, oral tongue, tonsil, and retromolar trigone region of the anterior faucial pillar had their primary lesions treated by radiotherapy alone for cure. One hundred twenty-eight of the patients were evaluable for this study. Bone and soft tissue morbidity were graded according to the late radiation scoring scheme of the radiation therapy oncology group of the European Organization on Research and Treatment of Cancer, tallying only grade 4 changes. Patients were further classified according to site of tumor, age, sex, tumor stage, histologic grade, and dental status--none of which had a positive correlation with complications. Of 31 evaluable patients with cancer of the floor of the mouth (median follow-up 136 months), 71 percent (22 of 31 patients) had at least one complication involving bone (osteonecrosis, pathologic fracture) or mucus membrane (ulcer). Sixty-one percent (25 of 41 patients) with primary cancer of the oral tongue had grade 4 sequelae (median follow-up 112 months). In 26 patients with cancer of the tonsil, 13 (50 percent) had grade 4 sequelae (median follow-up 113 months). This included 11 patients with clinical and radiographic evidence of osteonecrosis, 6 of whom required mandibulectomy. Patients with cancer of the retromolar trigone region of the anterior faucial pillar fared the best (median follow-up 122 months). Late sequelae were noted in 40 percent (12 of 30 patients). The morbidity attendant to cure by radiotherapy included at least one significant complication of bone or soft tissue in 40 to 70 percent of the patients, depending on the location of the primary tumor. There was also a positive correlation with dose of radiation received.