Effect of Second-generation vs Third-generation Chemotherapy Regimens with Thoracic Radiotherapy on Unresectable Stage III Non-Small-Cell Lung Cancer: 10-Year Follow-up of a WJTOG0105 Phase 3 Randomized Clinical Trial

Importance: Insufficient data are available regarding the long-term outcomes and cumulative incidences of toxic effects that are associated with chemoradiotherapy (CRT) for patients with stage III non-small-cell lung cancer. Objective: To evaluate survival and late toxic effects 10 years after patients were treated with curative CRT. Design, Setting, and Participants: This multicenter, phase 3 West Japan Thoracic Oncology Group (WJTOG) 0105 randomized clinical trial was conducted between September 2001 and September 2005 in Japan. Patients with histologically or cytologically confirmed non-small-cell lung cancer with unresectable stage III disease were assessed for eligibility. Additional data were analyzed from January 2018 to December 2019. Interventions: A total of 440 eligible patients were randomly assigned to groups as follows: A (control), 4 cycles of mitomycin/vindesine/cisplatin plus thoracic radiotherapy (TRT) of 60 Gy; B, weekly irinotecan/carboplatin for 6 weeks plus TRT of 60 Gy followed by 2 courses of irinotecan/carboplatin consolidation; or C, weekly paclitaxel/carboplatin for 6 weeks plus TRT of 60 Gy followed by 2 courses of paclitaxel/carboplatin consolidation. Main Outcomes and Measures: The primary outcome was 10-year survival probability after CRT. The secondary outcome was late toxic effects that occurred more than 90 days after initiating CRT. Results: From September 2001 to September 2005, 440 patients (group A, n = 146 [33.2%; median (range) age, 63 (31-74) years; 18 women (12.3%)]; group B, n = 147 [33.4%; median (range) age, 63 (30-75) years; 22 women (15.0%)]; group C, n = 147 [33.4%; median (range) age, 63 (38-74) years; 19 women (12.9%)]) were enrolled. The median (range) follow-up was 11.9 (7.6-13.3) years. In groups A, B, and C, median (range) overall survival times were 20.5 (17.5-26.0), 19.8 (16.7-23.5), and 22.0 (18.7-26.2) months, respectively, and 10-year survival probabilities were 13.6%, 7.5%, and 15.2%, respectively. There were no significant differences in overall survival among treatment groups. The 10-year progression-free survival probabilities were 8.5%, 6.5%, and 11.1% in groups A, B, and C, respectively. Grade 3 or 4 late toxic effect rates were 3.4% (heart, 0.7%; lung, 2.7%) in group A, and those only affecting the lung represented 3.4% and 4.1% in groups B and C, respectively. No other cases of late toxic effects (grades 3/4) were observed since the initial report. Conclusion and Relevance: In this 10-year follow-up of a phase 3 randomized clinical trial, group C achieved similar efficacy and toxic effect profiles as group A 10 years after initiating treatment. These results serve as a historical control for the long-term comparisons of outcomes of future clinical trials of CRT. Trial Registration: UMIN Clinical Trial Registry: UMIN000030811.