Postoperative chemoradiotherapy is superior to postoperative chemotherapy alone in squamous cell lung cancer patients with limited N2 lymph node metastasis

Liyu Su,Huiyan Su,Mingqiu Chen,Jiancheng Li,Yaqing Dai,Shaoxing Chen

doi:10.1186/s12885-019-6141-z

Abstract

BackgroundThe aim of the present study was to assess the efficacy of postoperative chemoradiotherapy (POCRT) following surgery in non-small-cell lung cancer patients with N2 lymph node metastasis (N2-NSCLC).MethodsThe clinical data of patients with N2-NSCLC treated with POCRT or postoperative chemotherapy (pCT) alone were retrospectively collected and reviewed. The overall survival (OS) rates were analyzed utilizing the Kaplan-Meier method and compared by the log-rank test. Cox regression analysis was used to determine factors significantly associated with survival. Propensity score matching (PSM) analysis was used to compensate for differences in baseline characteristics and OS was compared after matching.ResultsBetween 2004 and 2014, a total of 175 patients fulfilled the inclusion criteria, 60 of whom were treated with POCRT, while 115 were administered pCT. The 1, 3 and 5-year OS rates in the POCRT and pCT groups were 98.3 vs. 86.1%, 71.7 vs. 53.0% and 45.7 vs. 39.0%, respectively (P = 0.019). Compared with pCT, POCRT improved OS in patients with squamous cell subtype (P = 0.010), no lymphovascular invasion (P = 0.006), pN2a (P = 0.006) or total number of metastatic lymph nodes ≤7 (P = 0.016). After PSM, these survival differences between POCRT and pCT remained significant in patients with squamous cell lung cancer (P = 0.010).ConclusionsPOCRT following complete resection may be beneficial for patients with squamous cell lung cancer, particularly those with limited nodal involvement.

Highlights

The aim of the present study was to assess the efficacy of postoperative chemoradiotherapy (POCRT) following surgery in non-small-cell lung cancer patients with N2 lymph node metastasis (N2-NSCLC)
No significant differences in clinical characteristics were identified between the two groups, with the exception of surgical modality and total number of chemotherapy cycles (Table 1), which did not affect patient survival in the subsequent multivariate analyses
Following Propensity score matching (PSM), POCRT still clearly demonstrated superior survival compared with postoperative chemotherapy (pCT), indicating that POCRT should be considered for patients with N2-NSCLC, despite the fact that no randomized clinical trials have been conducted to validate it far [17]

Summary

Introduction

The aim of the present study was to assess the efficacy of postoperative chemoradiotherapy (POCRT) following surgery in non-small-cell lung cancer patients with N2 lymph node metastasis (N2-NSCLC). Postoperative chemotherapy (pCT) is considered as the standard postoperative treatment for NSCLC patients with metastases to the lymph nodes [5]. It has come to be considered that postoperative radiotherapy (PORT) should be added to BMT to improve local control and survival, this may not be the case, as several clinical trials confirmed that POCRT did not improve the survival of patients with N1 stage disease after complete (R0) resection [8]. For patients with metastases to the ipsilateral mediastinal lymph nodes (N2-NSCLC), the role of PORT following BMT remains controversial due to its variable response rates and effectiveness [9]

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