Failure patterns by prognostic group determined by recursive partitioning analysis (RPA) of 1547 patients on four radiation therapy oncology group (RTOG) studies in inoperable nonsmall-cell lung cancer (NSCLC).

Komaki R, ScInt J Radiat Oncol Biol Phys 1998 Sep 1;42(2):263-7

From 4 RTOG trials, 1547 patients treated by RT alone were analyzed for patterns of first failure by RPA class defined by prognostic factors, including KPS, weight loss, nodal stage, pleural effusion, age and radiation therapy dose. All patients had NSCLC AJCC Stage II, IIIA, or IIIB, KPS > 50, with no previous RT or chemotherapy. The RPA classes were 4 distinct subgroups that had significantly different median survivals of 12.6, 8.3, 6.3 and 3.3 months for Classes I, II, III and IV, respectively..When the survival was calculated for RPA among the patients who had weight loss < 5% and the dose received rather than prescribed, 66 Gy or higher was associated with a median survival of 12.3 months compared to 9.8 months among the patients who received less than 66 Gy. Two-year survival rates for those two groups were 29% vs. 24%, respectively. Overall median survival of the whole group was 9 months. Patients in Class I with KPS 80–100, nodes negative, age younger than 70, assigned radiation therapy dose 66 Gy, and weight loss 5% had a median survival of 12.6 months and a 2-year survival rate of 25%. Class II had KPS 80–100, node positive, age 60 or older, and radiation therapy dose was < 66 Gy and weight loss > 5% had a median survival of 8.3 months and a 2-year survival rate of 13%. Class III had a KPS of 70 or less and negative pleural effusion; the median survival was 6.2 months and an 8% 2-year survival rate. Class IV, with a KPS 70 or less and positive pleural effusion, had a median survival of 3.3 months and 5% 2-year survival rate.