Effect of Second-generation vs Third-generation Chemotherapy Regimens With Thoracic Radiotherapy on Unresectable...

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.

To evaluate survival and late toxic effects 10 years after patients were treated with curative CRT.

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.

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.

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.

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.

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.

UMIN Clinical Trial Registry: UMIN000030811.