EP1.18-04 Do Tumor-Related Factors Predict Postoperative Pulmonary Complications in Patients Undergoing Curative Surgery for Lung Cancer?

Abstract

Background: The pattern of postoperative recurrence among patients with stage III/N2 EGFR-mutant non-small cell lung cancer (NSCLC) is seldom reported. Moreover, the clinical value and optimal candidate of postoperative radiotherapy (PORT) for stage III/N2 NSCLC is still controversial. Method: Consecutive patients who underwent curative resection and were pathologically confirmed EGFR-positive stage III/N2 NSCLC at Fudan University Shanghai Cancer Center from January 2007 to December 2017, were retrospectively enrolled. Serial imaging scans of each patient were intensively examined and the initial recurrence sites were categorized into five groups: thoracic recurrence, brain recurrence, neck recurrence, abdominal recurrence, and bone recurrence. Recurrence-free survival (RFS) were estimated by Kaplan-Meier curves. The Cox proportional hazards model was applied to estimate the association between RFS and clinic-pathological parameters (including age, sex, tumor size, TNM stage, tumor differentiation, tumor histology, lymphovascular invasion, visceral pleural invasion, and EGFR mutation subtypes), as well as a panel of routinely used immunohistochemical markers (including Her2, Ki67, TTF-1, CK20, CK7, CK5/6, p53, RRM1, NapsinA, p40, syn, Bcl-2, CDX2, ERCC1 and p63). Result: Ninety-one patients were identified, all of whom received adjuvant chemotherapy and 28 of whom received PORT. After a median follow up of 28 (range, 6-103) months, disease recurrence occurred in 62 patients. Thirty-six (58.1%) patients had thoracic recurrence, 15 (24.2%) had bone recurrence, 14 (22.6%) had brain recurrence, 9 (14.5%) had neck recurrence, and 8 (12.9%) had abdominal recurrence. Nineteen patients had multiple sites of initial recurrence. In terms of thoracic recurrence, initial relapse at the resection margin occurred in 1 patients and relapse in the mediastinal or ipsilateral hilar lymph nodes was observed in 11 patients. Ki6745% and positive expression of ERCC1 were identified as independent predictors of postoperative recurrence in multivariate analysis. Of note, PORT was not significantly associated with RFS in the whole population (p¼0.877). However, among the 62 patients who had at least one of the independent predictors of postoperative recurrence (ie: Ki6745%, expression of ERCC1), PORT (n¼22) significantly prolonged RFS (p¼0.043). Conclusion: The majority of patients with stage III/N2 EGFR-mutant NSCLC developed their initial recurrence in the thorax. Patients with Ki6745% and/or positive expression of ERCC1 have a significant higher risk of postoperative recurrence, who may be the potential candidate for PORT.