Randomized study of chemotherapy/radiation therapy combinations for favorable patients with locally advanced inoperable nonsmall cell lung cancer: Radiation Therapy Oncology Group (RTOG) 92-04.

PURPOSE: The purpose of this study was to compare the severity and distribution of the toxicities associated with the two different combinations of chemotherapy and radiotherapy.

METHODS AND MATERIALS: This prospective randomized trial studied toxicities associated with induction chemotherapy followed by concurrent treatment (Arm 1) vs. immediate concurrent chemotherapy/radiotherapy (CT/RT) (Arm 2). Arm 1 consisted of vinblastine (VB), 5 mg/M2 I.V. bolus weekly, weeks 1-5 and cisplatin (DDP), 100 mg/M2 days 1 and 29, DDP 75 mg/M2, days 50, 71, and 92. Daily RT started on day 50; a total dose of 63 Gy was given in 34 fractions in 7 weeks. In Arm 2 RT started day 1; a total dose of 69.6 Gy was given in 58 fractions of 1.2 Gy bid, 5 days per week for 6 weeks with DDP 50 mg/M2 i.v. days 1 and 8, and oral VP-16 50 mg b.i.d. during the first 10 days of RT. DDP/VP-16 were repeated beginning day 29. Survival was used as the Phase II endpoint.

RESULTS: Between July 1992 and February 1994, 168 patients were randomized; 162 evaluable patients had minimum follow-up of 20 months. Eighty patients were registered to Arm 1 and 82 to Arm 2. Pretreatment characteristics were distributed evenly. Arm 1 had significantly more Grade 4 hematologic toxicity (62%) than Arm 2 (33%) (p = 0.021). Acute nonhematologic Grade 3+ toxicity was also greater (p = 0.018) in Arm 2 than Arm 1 due mainly to esophagitis (38 vs. 6%; p < 0.0001). Grade 3+ late esophageal toxicity was 12% on Arm 2 compared to 3% on Arm 1 (p = 0.006). There were no differences between the two arms in compliance with protocol specifications for either RT or CT. At 1 year, 31.7% of patients had in-field progression on Arm 1 compared to 19.8% on Arm 2 (p = 0.042), but overall progression-free survival rates were nearly identical; 50 and 49% for Arms I and II, respectively, at 12 months. One-year and median survivals were 65% and 15.5 months on Arm 1 compared to 58% and 14.4 months on Arm 2.

CONCLUSION: Whereas hematologic toxicity was greater in Arm 1, esophageal toxicity, both acute and late, was greater in Arm 2. Infield progression was lower in Arm 2, but overall progression rates were similar and there were no significant differences in survival between the two arms. A 3-arm randomized Phase III study is underway in the RTOG to compare sequential and concurrent CT/RT.