The Prognostic Role of PORT and EGFR Mutation Status in Completely Resected Stage IIIA/N2 Non-Small Cell Lung Cancer Patients with Postoperative Chemotherapy

Abstract

Background: The treatment choice for completely resected stage IIIA/N2 non-small cell lung cancer (NSCLC) patients is still controversial now. Our study aims to identify potential prognostic factors in stage IIIA/N2 NSCLC patients with complete surgical resection and postoperative chemotherapy.Methods: In this study, we screened the stage IIIA/N2 NSCLC patients diagnosed in the Affiliated Cancer Hospital of Zhengzhou University from 2015 to 2019. Completely resected patients with postoperative chemotherapy (PCT) were enrolled. The univariate and multivariate COX proportional hazards regression analyses were used to identify the prognostic factors. The Kaplan-Meier survival curve was used to compare the disease-free survival (DFS) and overall survival (OS) in the subgroup analyses.Results: 180 patients were collected, including 142 patients with PCT treatment alone and 38 patients with postoperative radiotherapy (PORT) treatment. The median DFS was 17.8 months (95% CI: 16.5–19.1 months) and the median OS was 50.6 months (47.4–53.9 months) in all the patients. The median DFS of the PORT group was significantly longer than the PCT group (38.7 vs 16.7 months, p < 0.001). Epidermal growth factor receptor (EGFR) mutation-positive patients had a worse DFS compared with EGFR mutation-negative patients (16.8 vs 18.0 months, p = 0.032). Possible prognostic factors were evaluated through univariate COX regression analysis. The further multivariate COX regression analysis showed that patients with PORT (HR: 0.318, 95% CI: 0.185–0.547, p < 0.001), EGFR mutation-negative (HR: 0.678, 95% CI: 0.492–0.990, p = 0.044), T1 (HR: 0.661, 95% CI: 0.472–0.925, p = 0.016), and lobectomy (HR: 0.423, 95% CI: 0.191–0.935, p = 0.034), had better DFS. The only independent prognostic factor of OS was the type of surgery (p = 0.013).Conclusion: PORT might improve the DFS of stage IIIA/N2 NSCLC patients with complete surgical resection and PCT, but it cannot increase OS. Besides, EGFR mutation status, T stage, and type of surgery are possible independent prognostic factors for DFS, and type of surgery is associated with OS. These factors remain to be clarified in further studies.

Effect of postoperative radiotherapy on survival in patients with completely resected and pathologically confirmed stage N2 non-small-cell lung cancer: a systematic review and meta-analysis

“…In all, 20 studies 13,18,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37][38] were finally included after literature screening, including 6 randomized controlled trials and 14 retrospective studies. A total of 6340 patients were enrolled, of which 1972 patients received PORT and 4368 patients did not.…”

The efficacy of postoperative radiotherapy in resected pⅢA-N2 EGFR mutant and wild-type lung adenocarcinoma

“… 14 , 15 , 17 The prognostic significance of EGFR mutation status in patients who underwent PORT was unclear. 18 , 19 In our study, the results revealed that PORT was not associated with better survival outcomes in pⅢA-N2 NSCLC with EGFR mutation, which suggested that targeted therapy may be a more suitable adjuvant treatment option. For EGFR wild-type patients, the options for adjuvant therapies are limited.…”

Clinical management of stage III non‐small cell lung cancer in India: An expert consensus statement

“…Significant improvement in local control and survival was reported with postoperative radiotherapy (PORT), with or without chemotherapy in patients with resectable stage IIIA‐N2 NSCLC 33 . However, a recent RCT noted that although PORT improves disease‐free survival (DFS), OS was not increased 34 . According to a phase III RCT involving 364 patients with stage IIIA‐N2 NSCLC and a history of complete resection and adjuvant chemotherapy, DFS in the intent‐to‐treat population was not increased with PORT; however, a significant improvement was noted in the per‐protocol population and in preplanned exploratory stratified analysis.…”

“…33 However, a recent RCT noted that although PORT improves diseasefree survival (DFS), OS was not increased. 34 According to a phase III RCT involving 364 patients with stage IIIA-N2 NSCLC and a history of complete resection and adjuvant chemotherapy, DFS in the intent-to-treat population was not increased with PORT; however, a significant improvement was noted in the per-protocol population and in preplanned exploratory stratified analysis. Furthermore, there was no improvement in OS with PORT.…”