Purpose: There are no published survival data after chemoradiotherapy (chemoRT) in pathologically documented stage IIIB non-small-cell lung cancer. Studies of radiotherapy (RT) alone or chemotherapy followed by RT yield 5-year survivals less than 10%. The Southwest Oncology Group (SWOG) employed the same concurrent chemoRT induction regimen used in its predecessor trimodality trial to determine the efficacy, safety, and long-term outcome of replacing postinduction surgery with additional chemoRT.
Patients and methods: Eligible patients for SWOG-9019 had pathologic documentation of T4N0/1, T4N2, or N3 stage IIIB non-small-cell lung cancer. They had pulmonary function adequate to withstand combined-modality therapy, identical to the requirements of the previous trial with postchemoRT surgery. Induction therapy was two cycles of cisplatin plus etoposide (PE) concurrent with once-daily thoracic RT (45 Gy). In the absence of progressive disease, RT was completed to 61 Gy, with two additional cycles of cisplatin plus etoposide.
Results: Fifty eligible patients were accrued with tumor-node (TN) substage confirmed on central review: 18, T4N0/1; 12, T4N2; and 20, N3. Grade 4 neutropenia was the most common toxicity (32%). Grade 3/4 esophagitis occurred in 12% and 8%. Median follow-up was 52 months, and overall median survival was 15 months (10 to 22, 95% confidence interval). Three- and 5-year survivals were 17% and 15% (5-year T4N0/1, 17%; T4N2, 13%; and N3, 15%).
Conclusion: Feasibility and long-term survival support the application of these results as a standard against which mature outcomes of chemoRT trials with new chemotherapy agents can be compared. These results also justify use of the SWOG-9019 approach as a control arm in ongoing phase III trials.