Evaluation of Postoperative Radiotherapy Effect on Survival of Resected Stage III-N2 Non-small Cell Lung Cancer Patients

Abstract

The role of postoperative radiotherapy (PORT) in resected stage IIIA-N2 non-small cell lung cancer (NSCLC) patients remains controversial. This study aimed to explore the effect of PORT on survival of resected stage IIIA-N2 NSCLC patients. Methods: Resected stage IIIA-N2 NSCLC patients aged 18 years or older were identified from the SEER (Surveillance, Epidemiology, and End Results) database from 2010 to 2015. Cox regression analysis was used to identify factors including PORT associated with survival time. A subgroup analysis of patients stratified by number of lymph node metastases was also performed. Overall survival (OS) and overall mortality were compared among the different groups. Results: A total of 3,445 patients were included in the study. Multivariate Cox analysis showed that PORT had no significant impact on survival of patients with <6 positive lymph node [hazard ratio (HR) = 1.012, P = 0.858, 95% CI: 0.886-1.156]. Postoperative chemotherapy (POCT) (HR = 0.605, P < 0.001, 95% CI: 0.468-0.783) and PORT (HR = 0.724, P = 0.007, 95% CI: 0.574-0.914) are both favorable prognostic factors for stage IIIA-N2 patients with ≥6 positive lymph nodes. In 2,735 patients who featured <6 number of positive regional lymph nodes, patients who received PORT had better survival and lower 3-years and 5-years overall mortality rate than patients who underwent surgery only (41 vs. 28 months, P < 0.015). There was no significant difference in the survival of postoperative patients who underwent POCT in view of whether received PORT (44 vs. 53 months, P = 0.176). A total of 710 patients who featured ≥6 number of positive regional lymph node metastasis were divided into two groups by PORT. PORT did not prolong survival for postoperative patients who did not receive chemotherapy (12 vs. 15 months, P = 0.632). PORT showed a significant advantage in influencing OS in patients who received PORT combined with POCT as compared with those who received POCT only (32 vs. 25 months, P = 0.006). Conclusions: For IIIA-N2 patients with <6 lymph node metastases, use of PORT can be encouraged to improve survival. For patients with ≥6 positive lymph nodes, PORT combined with POCT significantly improved OS and decreased overall mortality.

Identification of Resectable N2 in NSCLC: A Single Center Experience and Review of the SEER Database

“…Keywords: NSCLC, SEER, resectable, nomogram, prognosis BACKGROUND N2 refers to lung cancer metastasis in ipsilateral mediastinal lymph nodes, which accounts for approximately 20%-30% of all non-small cell lung carcinoma (NSCLC) (1,2). Although many treatment strategies (bimodality or trimodality) exist for N2 NSCLC, the effectiveness of these therapeutic strategies remains unsatisfactory and the 5-year survival rate ranges from 23%-36% (3,4).…”

Lobectomy Versus Sublobectomy in Stage IIIA/N2 Non-Small Cell Lung Cancer: A Population-Based Study

“…A subgroup analysis in a multicenter retrospective study performed by Gao et al. also suggested no significant difference in survival outcome between surgery plus chemoradiotherapy and surgery plus chemotherapy, while another subgroup analysis in this research indicated surgery plus radiotherapy exhibited better survival than surgery alone, however, these analyses were univariable based on survival curves ( 1 ). Whether radiotherapy can provide benefit for resectable stage IIIA/N2 NSCLC patients especially for these who can’t accept chemotherapy is still unclear.…”

“…Pless and colleagues conducted a randomized trial comparing induction chemoradiotherapy with induction chemotherapy plus surgery and found radiotherapy did not confer benefit, suggesting one definitive local treatment modality combing neoadjuvant chemotherapy is appropriate to for resectable stage IIIA/N2 NSCLC (36). A subgroup analysis in a multicenter retrospective study performed by Gao et al also suggested no significant difference in survival outcome between surgery plus chemoradiotherapy and surgery plus chemotherapy, while another subgroup analysis in this research indicated surgery plus radiotherapy exhibited better survival than surgery alone, however, these analyses were univariable based on survival curves (1). Whether radiotherapy can provide benefit for resectable stage IIIA/N2 NSCLC patients especially for these who can't accept chemotherapy is still unclear.…”

“…Lung cancer is one of the most common malignancies with the highest morbidity and mortality around the world. Non-small cell lung cancer (NSCLC) is the most frequent subtype, which accounts for approximately 80–85% of lung cancer ( 1 ), and 10–20% of NSCLC patients are diagnosed with N2-positve clinical stage IIIA (IIIA/N2) disease ( 2 ). The treatment modalities for stages I, II, IIIB, and IV NSCLC have been sufficiently studied and applied worldwide.…”

Log odds of positive lymph nodes is a robust predictor of survival and benefits from postoperative radiotherapy in stage IIIA‐N2 resected non‐small cell lung cancer

“…It has been reported that a number of clinicopathological factors such as age, gender, grade, T‐stage, chemotherapy and LNR, were all independent risk factors for patients with poor prognosis 15,27–29 . Notably, recent years witnessed an increase in retrospective studies to explore potential candidates with stage IIIA‐N2 disease for PORT 12,28–33 . Furthermore, it was common that the number or ratio of positive nodes was identified as a predictor of responses to PORT in previous studies 12,28,29,33,34 .…”