Targeted therapy for common- versus rare-mutations of epidermal growth factor receptor in non-small cell lung cancer: A single center analysis of real-world data

  Background  Patients with non-small cell lung cancer (NSCLC) with common or rare epidermal growth factor receptor (EGFR) mutations differ in the response to targeted therapy, but there are few direct comparisons in the real world.

  Objective  To evaluate the effect of tyrosine kinase inhibitors (TKI) on the clinical prognosis of patients with common mutations and rare mutations of EGFR, and address the factors affecting the clinical prognosis.

  Methods  Clinical data about patients with common or rare EGFR mutated NSCLC who received EGFR-TKIs in the First Medical Center of Chinese PLA General Hospital from August 1, 2019 to December 31, 2021 were collected for retrospective analysis. The objective response rate (ORR), disease control rate (DCR) and progression-free survival (PFS) of the two groups were analyzed.

  Results  A total of 99 patients were included in the study, including 79 common mutations in EGFR and 20 rare mutations. The common mutation group had an ORR of 63.3% and a DCR of 93.7%. In the rare mutation group, ORR was 35.0% and DCR was 65.0%, the curative effect of patients with common EGFR mutations was better than that of patients with rare EGFR mutations (P＜0.05). Cox regression analysis suggested that EGFR mutation type was an independent factor affecting PFS in the NSCLC patients (P<0.05). Kaplan Meier survival analysis showed that there was a significant difference in the prognosis of patients with common mutations and patients with rare mutations receiving targeted therapy (median PFS: 13.3 months vs 6.0 months, P=0.006).

  Conclusion  Patients with rare mutations have poorer outcomes and prognosis than those with common mutations.