Suda K, et al. Ann Thorac Surg 2020.
BACKGROUND: To elucidate the clinical, pathologic, and prognostic impacts of EGFR mutation and mutation subtypes in early-stage lung cancer, we conducted a retrospective analysis of the Japanese Joint Committee of Lung Cancer Registry database (a nationwide database for surgically-resected lung cancer patients; n = 18,973).
METHODS: Of 13,951 patients classified as non-squamous non-small cell lung cancer in the database, 5,780 patients (41.0%) had been tested for EGFR mutation and were included in this study.
RESULTS: EGFR mutation was detected in 2,410 patients (41.7%), and presence of EGFR mutation was significantly correlated with clinicopathological factors such as the presence of ground-glass opacity (P < 0.001) and better prognosis. Analysis of initial recurrence sites identified significantly higher frequencies of brain and adrenal gland metastases in patients with and without EGFR mutation, respectively. Of 2,410 patients with EGFR mutations, 983 (40.8%) had exon 19 deletion (Exon 19 Del), 1,170 (48.5%) had L858R mutation, and 257 (10.7%) had other EGFR mutations. Higher smoking rate was found in patients with other EGFR mutations (p = 0.02). In the comparison of Exon 19 Del and L858R, we found that Exon 19 Del correlated with younger age (P < 0.001), higher rate of pure solid tumors (P < 0.001), advanced pathological stage (trend P = 0.0004), and poorer recurrence-free survival (P = 0.001).
CONCLUSIONS: In addition to clinicopathological and prognostic impacts of EGFR mutation status, tumors with Exon 19 Del have a more aggressive phenotype and poorer prognosis than those with L858R in early-stage lung cancers.