1535 - EGFR mutation is not a prognostic factor in completely resected lymph node–negative pulmonary adenocarcinoma (LNNPA)

Background

EGFR mutation is the major driver mutation in East Asian lung cancer. By and large, this group of lung cancer patients has a better prognosis in advanced stage pulmonary adenocarcinoma. However, the prognostic role of these sensitizing EGFR mutations in early stage is uncertain. We aimed to investigate the prognostic value of EGFR mutation and other factors for tumor recurrence in completely resected LNNPA.

Methods

We recruited 220 patients with LNNPA who were diagnosed and treated at the King Chulalongkorn Memorial Hospital from January 1, 2009 to December 31, 2016. Recurrence included pathological diagnosis, imaging confirmations, or death. Recurrence-free survival was analyzed by univariable and multivariable Cox regression analyses.

Results

Median follow up time was 4 (2.7-5.6) years. There were more female (62%), never smokers (68%), stage I (86%) and EGFR mutations (54%). The most common EGFR mutations were exon 19 deletion (51%) and L858R (43%). Most patients did not receive adjuvant treatment (85.6%). There were 60 out of 220 (27.3%) patients had recurrent disease. The median time to recurrence was 2.3 years. The rate of loco-regional, distant and both types of recurrence were 27%, 68% and 5% respectively. Univariate analysis revealed smoking ≥ 10 pack-year, performance status ≥ 2, tumor size ≥ 4 cm, histologic grade ≥ 2, lymphovascular invasion, visceral pleural invasion, tumor necrosis and bronchial resection margin (BRM) < 2 cm were significant prognostic factors for tumor recurrence. However, tumor size ≥ 4 cm, visceral pleural invasion, tumor necrosis and BRM < 2 cm remained the significant prognostic factors with multivariate analysis (Table). Sensitizing EGFR mutation was not a significant prognostic factor in this cohort by both univariate and multivariate analyses.Table: 1451P

Multivariate analysis

Conclusions

Among Thai, East Asian, early stage lung cancer, sensitizing EGFR mutation has similar outcomes to those without EGFR mutation.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Ratchadapisek Sompoch Endowment Fund.

Disclosure

All authors have declared no conflicts of interest.