Real-World Treatment of Stage III NSCLC: The Role of Trimodality Treatment in the Era of Immunotherapy.

INTRODUCTION

Curative intent treatment of stage III NSCLC is variable and influenced by both patient and disease characteristics. We performed a real-world analysis of curative therapies in stage III NSCLC, and explored the impact of known prognostic factors on outcome.

METHODS

A retrospective review was completed of all patients with stage III NSCLC between January 2005 and December 2012. Cases were filtered to identify those receiving curative intent therapy including surgery, radiotherapy (RT), chemoradiotherapy (CRT), and combined modality with surgery (S + RT). Information was collected on known prognostic and predictive factors, and immunotherapy eligibility per the PACIFIC trial. The primary outcome measure was overall survival.

RESULTS

A total of 638 patients with stage III NSCLC were referred and received curative intent treatment. Of these, 66 (10%) received surgery, 95 (15%) RT, 410 (64%) CRT, and 67 (11%) combined S + RT. Median overall survival (OS) was similar for surgery (28.6 mo) and CRT (27.0 mo), inferior for RT alone (17.5 mo), and superior for S + RT (55.8 mo). In a multivariate model only, Eastern Cooperative Oncology Group performance status (ECOG PS) and treatment cohort significantly influenced OS. In a case-matched analysis, the median OS for CRT was 31.9 months, compared to 55.8 months with trimodality treatment. Overall, 61% of patients receiving CRT and 88% of those receiving trimodality therapy would have been potentially eligible for adjuvant immunotherapy.

CONCLUSIONS

In stage III NSCLC, the performance of surgery and CRT are similar after controlling for known prognostic factors. Radiotherapy alone is associated with worse outcomes. Combined S + RT appears to provide a significant benefit above other modalities, albeit in highly selected patients.