Local Consolidative Therapy Vs. Maintenance Therapy or Observation for Patients With Oligometastatic Non–Small-Cell Lung Cancer: Long-Term Results of a Multi-Institutional, Phase II, Randomized Study

Abstract

PURPOSE: Our previously published findings reported that local consolidative therapy (LCT) with radiotherapy or surgery improved progression-free survival (PFS) and delayed new disease in patients with oligometastatic non–small-cell lung cancer (NSCLC) that did not progress after front-line systemic therapy. Herein, we present the longer-term overall survival (OS) results accompanied by additional secondary end points. PATIENTS AND METHODS: This multicenter, randomized, phase II trial enrolled patients with stage IV NSCLC, three or fewer metastases, and no progression at 3 or more months after front-line systemic therapy. Patients were randomly assigned (1:1) to maintenance therapy or observation (MT/O) or to LCT to all active disease sites. The primary end point was PFS; secondary end points were OS, toxicity, and the appearance of new lesions. All analyses were two sided, and P values less than .10 were deemed significant. RESULTS: The Data Safety and Monitoring Board recommended early trial closure after 49 patients were randomly assigned because of a significant PFS benefit in the LCT arm. With an updated median follow-up time of 38.8 months (range, 28.3 to 61.4 months), the PFS benefit was durable (median, 14.2 months [95% CI, 7.4 to 23.1 months] with LCT v 4.4 months [95% CI, 2.2 to 8.3 months] with MT/O; P = .022). We also found an OS benefit in the LCT arm (median, 41.2 months [95% CI, 18.9 months to not reached] with LCT v 17.0 months [95% CI, 10.1 to 39.8 months] with MT/O; P = .017). No additional grade 3 or greater toxicities were observed. Survival after progression was longer in the LCT group (37.6 months with LCT v 9.4 months with MT/O; P = .034). Of the 20 patients who experienced progression in the MT/O arm, nine received LCT to all lesions after progression, and the median OS was 17 months (95% CI, 7.8 months to not reached). CONCLUSION: In patients with oligometastatic NSCLC that did not progress after front-line systemic therapy, LCT prolonged PFS and OS relative to MT/O.