Factors affecting outcome in resected EGFR-mutated lung cancer

Abstract

Introduction Long-term data on disease trajectory of EGFR-mutated early-stage non-small cell lung cancer (NSCLC) is still limited. This is relevant in the context of the recently approved introduction of adjuvant EGFR-targeting therapy, specifically osimertinib in resected stage II–III EGFR-mutated NSCLC. Methods Long-term data on patients with resected adenocarcinoma of the lung and known EGFR-status were analysed with focus on site of relapse and detailed cause of death. Patients resected in the period 2006 to 2018 were included. Results Of 503 patients (286 (57%) females, median age 67.3 years), 62 (12%) harboured an EGFR-mutation, 286 (57%) were in stage I. After a median follow-up of 8.0 years, 241 (48%) patients relapsed. Recurrence occurred in 30% and 53% of EGFR-positive stage IA and IB patients, respectively. Median overall survival was longer in EGFR-mutated versus non-mutated patients (128 versus 88 months). The recurrence rate, time to recurrence and rate of brain metastases was not different between EGFR-mutated and non-mutated groups. Median time from recurrence to death was longer in EGFR-mutated patients (31 months) compared with non-mutated patients (15 months). More patients without EGFR-mutation succumbed to non-cancer related death (18%) compared to patients with EGFR-mutations (8%). Conclusions The recurrence pattern in EGFR-mutated and non-mutated NSCLC-patients is similar and the rate is high in early stages. Time from recurrence to death and overall survival is longer in the EGFR-mutated group, due to lower risk of non-lung cancer deaths, and efficient treatment upon relapse.