Basis for new strategies in postoperative radiotherapy of bronchogenic carcinoma

In order to improve our understanding of the role of postoperative radiotherapy and to search for new strategies in the management of N1, N2, T3 stage carcinoma of the lung, we analyzed results of treatment in 148 of 166 patients who were registered at the Massachusetts General Hospital Tumor Registry from 1971 to 1977 with a pathological diagnosis of N1, N2, T3 carcinoma of the lung after pulmonary resection. Ninety-three patients received postoperative radiotherapy and another 55 were followed without further treatment. Patients with adenocarcinoma showed significant improvement of survival by postoperative radiotherapy; actuarial NED (no evidence of disease) survival rates were 85% and 51% at 1 year, and 43% and 8% at 5 years for S + RT (patients treated with surgery plus postoperative radiotherapy) and S (patients treated with surgery only) groups, respectively, (P < 0.01). The brain was the most common site of failure in adenocarcinoma, 53% and 58% of all failures occurred in the brain in S and S + RT groups suggesting elective whole brain irradiation in a future trial. For the squamous cell carcinoma group, there was no improved survival in the irradiated patients, actuarial NED survival rates were 63% for both S + RT and S groups at 2 years, and 42% and 33% for S + RT and S groups at 4 years. These figures should be considered in the light of the following: In 52% (24/46) of S + RT vs. 27% (8/29) of S group, disease was in N2, T3 stages. Regional recurrence was the most common failure in squamous cell carcinoma; 76% (13/17) and 45% (10/22) of all failures were in the regional area in S and S + RT groups. Regional failure in S + RT group was noted with radiation dose up to 5000 rad (TDF 82) which suggests radiation dose higher than 5000 rad in future trial