Dose-Escalation Study of Thoracic Radiotherapy in Combination With Pemetrexed Plus Cisplatin in Japanese Patients With Locally Advanced Nonsquamous Non-Small Cell Lung Cancer: A Post Hoc Analysis of Survival and Recurrent Sites

We performed a post hoc analysis of progression-free survival (PFS), overall survival (OS), and recurrent sites in patients with locally advanced nonsquamous non-small cell lung cancer who were enrolled in a phase I trial of combination chemotherapy consisting of pemetrexed plus cisplatin with concurrent thoracic radiotherapy. Patients received pemetrexed (500 mg/m²) plus cisplatin (75 mg/m²) on day 1 every 3 weeks for 3 cycles plus concurrent thoracic radiotherapy consisting of 60 Gy (n=6) or 66 Gy (n=12); 4 to 6 weeks thereafter, patients received consolidation treatment with pemetrexed (500 mg/m) every 3 weeks for up to 3 cycles. We reviewed the medial records to collect data on progression, recurrent sites, late toxicity, and survival. No late radiation morbidity was observed. Thirteen patients (72%) exhibited disease progression: 8 patients had distant metastases, 8 patients had local recurrence (within the radiation field [n=6], outside the radiation field [n=2], and both [n=1]), and 3 patients had local recurrence plus distant metastases. The median PFS was 10.5 months (95% confidence interval [CI], 8.8-12.3), and the 3-year PFS rate was 28% (95% CI, 7.0-48.6). Ten of the 18 patients died of lung cancer. The median follow-up time for the censored cases was 42.8 months (range, 38.1 to 52.9 mo). The median OS was 27.3 months (95% CI, 13.1-41.6), and the 3-year OS rate was 50% (95% CI, 26.9-73.1). The median PFS and OS in our study were comparable to those of historical chemoradiotherapy controls.