Long-term effects of neoadjuvant radiotherapy, adjuvant radiotherapy, and chemotherapy-only on survival of locally advanced non-small cell lung Cancer undergoing surgery: a propensity-matched analysis

Xinyu Wang,Shaofei Su,Chang Yin,Xi Li,Meina Liu,Chaoli Zhang,Chao Wang

doi:10.1186/s12885-018-4900-x

Abstract

BackgroundThe optimal timing of radiotherapy (RT) with respect to surgery remains controversial for locally advanced non-small cell lung cancer (LA NSCLC) undergoing surgery and the long-term effect of neoadjuvant RT, adjuvant RT, and chemotherapy-only on survival is unknown.MethodsA retrospective study with Greedy 5 → 1 Digit propensity score matching technique was performed for locally advanced NSCLC patients identified from the Surveillance, Epidemiology, and End Results (SEER) database during 2004 to 2012. Kaplan-Meier and the log-rank test were conducted to compare NSCLC-specific survival. Cox proportional hazards multivariable regression was performed to assess the impact of different treatment regimens on cancer-specific mortality after adjustment for demographic factors, histology type, tumor grade, tumor size, nodal stage, and extent of resection.ResultsOne thousand, two hundred and seventy-eight locally advanced NSCLC patients undergoing surgery were identified after propensity matching. Cox regression analyses showed the risk of cancer-specific mortality is not significantly different among neoadjuvant RT, adjuvant RT, and chemotherapy-only. Subgroup analyses showed that for patients with T1/2 & N2/3, the surgery plus chemotherapy-only group showed markedly higher mortality risk (HR = 1.42, 95%CI:1.10–1.83) than the neoadjuvant RT group. Other risk factors include older age, higher tumor grade, larger tumor size, and greater lymph node involvement.ConclusionsThe findings of this study suggest that the benefit of additional neoadjuvant or adjuvant RT to chemotherapy may be linked to a proper selection of LA NSCLC patients who undergo surgery. The timing of radiotherapy should be decided on the premise of fully considering patients’ condition and the quality of life after treatment.

Highlights

The optimal timing of radiotherapy (RT) with respect to surgery remains controversial for locally advanced non-small cell lung cancer (LA NSCLC) undergoing surgery and the long-term effect of neoadjuvant RT, adjuvant RT, and chemotherapy-only on survival is unknown
One-third of NSCLC patients are diagnosed with locally advanced (LA) disease [4]
The RT arms did not confer an additional cancer-specific or overall survival advantage beyond that achieved with surgery plus chemotherapy alone

Summary

Introduction

The optimal timing of radiotherapy (RT) with respect to surgery remains controversial for locally advanced non-small cell lung cancer (LA NSCLC) undergoing surgery and the long-term effect of neoadjuvant RT, adjuvant RT, and chemotherapy-only on survival is unknown. American Cancer Society has estimated that there will be 222,500 new cases and 155,870 deaths caused by lung cancer in the United States in 2017 [2], of which non-small cell lung cancer (NSCLC) constitutes about 85% [3]. One-third of NSCLC patients are diagnosed with locally advanced (LA) disease (stage IIIA/IIIB) [4]. Since this is an extremely heterogeneous group, the optimal treatment remains controversial [5,6,7,8,9]. A combined modality approach of RT, chemotherapy, and surgery is routinely recommended for resectable LA patients, the optimal sequence is still under debate, and the prognosis remains poor with a high rate of distant metastasis and low five-year overall survival rate [4, 18]

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Discussion

Conclusion