Propensity score-matching analysis of postoperative radiotherapy for stage IIIA-N2 non-small cell lung cancer using the Surveillance, Epidemiology, and End Results database

Jintao Tian,Bingqun Wu,Xiaoping Song,Shenhai Wei,Limin Liu,Mian Xie

doi:10.1186/s13014-017-0836-6

Abstract

BackgroundTo investigate the effects of postoperative radiotherapy (PORT) on the survival of patients with resected stage IIIA-N2 non-small cell lung cancer (NSCLC).MethodsA total of 3,334 patients with resected stage IIIA-N2 NSCLC in 2004 to 2013 were identified in the Surveillance, Epidemiology, and End Results database and stratified according to use of PORT. Propensity score-matching (PSM) methods were used to balance the baseline characteristics of patients who did (n = 744) or did not (n = 744) undergo PORT. Overall survival (OS) and lung cancer-specific survival (LCSS) were compared between these two patient groups.ResultsAfter PSM, PORT increased OS (hazard ratio, 0.793; p = 0.001) and LCSS (hazard ratio, 0.837; p = 0.022) compared with no PORT. The OS benefit for PORT was mainly seen in patients aged <60 years (5-year OS, 35.4% versus 28.9% for PORT versus no PORT, respectively; p = 0.026) and in those who underwent lobectomy (5-year OS, 43.5% versus 34.5% for PORT versus no PORT, respectively; p = 0.001). The LCSS benefit for PORT was significant in patients undergoing lobectomy (5-year LCSS, 48.3% versus 42.3% for PORT versus no PORT, respectively; p = 0.036).ConclusionsThe survival benefits of PORT were primarily observed in patients with resected stage IIIA-N2 NSCLC who were <60 years of age or had undergone lobectomy.

Highlights

To investigate the effects of postoperative radiotherapy (PORT) on the survival of patients with resected stage IIIA-N2 non-small cell lung cancer (NSCLC)
Surgical resection remains the mainstay of therapy for NSCLC without metastasis, local relapse and distant metastasis can occur after surgery, especially at advanced disease stages
We explored the effects of PORT in patients with resected stage IIIA-N2 NSCLC using SEER data from 2004 to 2013 and propensity score-matching (PSM) methods

Summary

Introduction

To investigate the effects of postoperative radiotherapy (PORT) on the survival of patients with resected stage IIIA-N2 non-small cell lung cancer (NSCLC). Postoperative radiotherapy (PORT) sterilizes regions at risk of microscopic disease and is an appealing means of preventing locoregional recurrence and improving outcomes in NSCLC patients. Studies on patients with stage I, stage II, or stage IIIA NSCLC have been performed to test this hypothesis [3,4,5,6]. These studies consistently showed detrimental effects of PORT on the survival of early-stage (stages I and II) patients [4, 6,7,8,9]. PORT had survival advantages in a randomized trial of adjuvant chemotherapy, in which the use of PORT was not randomized or mandatory [4], and in two population-based cohort studies, one using the National Cancer Data Base (NCDB) [5] and the other using the Surveillance, Epidemiology, and End Results (SEER)

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