Oncogenic L858R mutation of human epidermal growth factor receptor (EGFR) confers constitutive activation to the kinase and is frequently observed in the pathological process of metastatic lung cancer.
There was a significant difference in newly development of lung metastasis between patients with exon 19 deletion and those with L858R mutation (41.4% vs. 6.3%, p=0.02).PPS was 8.9 months (95% CI, 7.4-10.4).