Major pathological response after preoperative chemotherapy as a surrogate marker of survival in early-stage non-small cell lung cancer: cohort of NATCH phase III trial

Abstract

Background: Randomized phase III NATCH trial in early‐stage non‐small cell lung cancer (NSCLC) patients (p) reported no statistically differences in disease‐free survival (DFS) or overall survival (OS) with the addition of preoperative or adjuvant chemotherapy to surgery. In pre‐operative arm, those p who achieved a complete response obtained a benefit in 5‐year DFS rate (59% vs. 38%). Recently, major pathological response (MPR) to preoperative chemotherapy (10% or less of residual viable tumor after preoperative therapy) has reported as surrogate marker of OS. The aim of this study is to validate MPR as prognostic factor in a cohort of patients included the NATCH trial. Methods: MPR was analysed in a whole cohort of 57 early‐stage NSCLC p treated in the preoperative arm into NATCH trial from 2 institutions. OS according to MPR was analysed (long‐rank test) in the whole population and by histologic subtype. Results: In this cohort, median age was 67 years (47‐78), 48 p (84%) were males, 26 p (46%) squamous subtype. By stage according to 6th TNM: 9 p (16%) stage IA, 35 p (61%) stage IB, 12 p (21%) stage IIB and 1 p (2%) stage IIIA. 95% p completed 3 cycles of preoperative treatment. Surgical procedures: 81% lobectomies, 14% pneumonectomies, 5% no surgery. 13 out of 57 p (22.8%) had MPR. In the whole population, there was an increase in 5‐year OS among those patients with MPR compare to p without MPR (84.6% vs. 58.5%, p=0.106). According to histological subtype, 5‐year OS in squamous NSCLC p with MPR was significantly longer than in p without MPR (100% vs. 47.1%, p=0.026), but not differences in OS in non‐squamous were detected (66.7% vs. 66.7%, p=0.586). Conclusions: MPR is a prognostic value in squamous NSCLC p who receive preoperative chemotherapy. Validation in extended cohort merits further evaluation.