Prognostic impact of complete remission after preoperative irradiation of tonsillar carcinoma: A retrospective analysis of the radiumhemmet data, 1980-1995

Purpose: This retrospective study was done to determine the outcome of patients with tonsillar carcinoma treated at Radiumhemmet, Karolinska Hospital, between January 1980 and December 1995 with radiotherapy alone or in combination with surgery. In addition the importance of tumor remission for patient survival was analyzed. Methods and Materials: The analysis is based on 167 previously untreated patients with biopsy-proven, invasive tonsillar squamous cell carcinoma of the tonsillar region. All patients were consecutively admitted to the Department of General Oncology, Radiumhemmet, and treated with curative intent. The median follow-up time was 20 months. The median target dose was 64 Gy, delivered in fractions of 2 Gy 5 times weekly. Twenty-eight percent of the patients underwent surgery of the primary site and/or neck dissection after radiotherapy (RT). Results: The overall local control rate for the whole patient group after radiotherapy was 79%. Probability of survival after 5 years for patients responding with complete remission (CR) was 43% and for patients,vith incomplete response (non-CR) 9%, (p < 0.0001). The survival in the non-CR group treated with combination therapy was 20 months longer than in patients receiving radiotherapy alone (p < 0.0001). There was no statistically significant difference in prediction of long-term survival when the patient population was stratified according to tumor differentiation grade, age, sex, nodal status, or treatment time. Conclusion: The strongest clinical predictor of survival was the degree of tumor remission after RT. For the non-CR group receiving combination treatment including surgery there was a survival benefit as compared to patients treated with RT alone (p < 0.0001) although there were few long-term survivors in this patient group. (C) 1999 Elsevier Science Inc.