Long-term treatment results of postoperative radiation therapy for advanced stage oropharyngeal carcinoma

Abstract

Background. The authors report the long-term treatment results for advanced stage base of tongue (BOT) and tonsillar fossa (TF) carcinomas treated with surgery and postoperative radiation therapy (RT) at Memorial Sloan-Kettering Cancer Center. Methods. Between 1973 and 1986, 51 patients with squamous cell carcinoma of the BOT (n = 31 patients) and TF (n = 20 patients) were treated with surgery plus RT. Indication(s) for RT included: advanced disease (Stage T₃/T₄, 34 patients [66%]); close or positive margins (33 patients, 64%) and multiple positive neck nodes (43 patients, 84%). Results. The 7-year actuarial local control rates for BOT and TF lesions were 81% and 83%, respectively. Local control was achieved in 17 of 18 (94%) patients with T₃ lesions, and 12 of 16 (75%) patients with T₄ lesions. Among patients with positive or close margins who received postoperative doses of 60 Gy or more, the long-term control rate was 93%. The presence of a treatment interruption had a negative effect on the local control rates. The actuarial control among patients who required a treatment break was 64%; for those not requiring interruption of their treatment, the actuarial control was 93% (P = 0.05). At 7 years, the overall survival for all patients was 52y0, and the disease-free survival was 64%. The actuarial incidence of neck failure was 21% and 18% for BOT and TF, respectively. The likelihood of having distant metastasis at 7 years for all patients was 30%. The actuarial incidence of having a second malignancy was 35% for patients with BOT disease. Second malignancy was not observed among patients with TF lesions. Conclusions. The authors conclude that surgery and postoperative RT can provide excellent long-term, disease-control rates for patients with advanced BOT and TF tumors. However, current strategies for BOT lesions have been directed at tongue preservation without surgery.