Liver metastasis predicts poorer prognosis in stage IV lung adenocarcinoma patients receiving first-line gefitinib.

Abstract

Gefitinib is currently used as a first-line therapy in patients of advanced non-small cell lung cancer (NSCLC) with susceptible epidermal growth factor receptor (EGFR) mutations. However, treatment outcomes of these patients vary. This study was conducted to evaluate the impact of specific metastatic sites on treatment outcomes of patients with stage IV lung adenocarcinoma with susceptible EGFR mutations receiving first-line gefitinib, focusing on the impact of liver metastasis. Between October 2009 and April 2014, patients of stage IV lung adenocarcinoma harboring EGFR mutation in exon 19 or 21, who received first-line gefitinib treatment, were enrolled in two hospitals and followed until December 22, 2014. The impacts of various clinical features, including sex, age, smoking history, performance status, EGFR mutation site, metastatic sites, etc., on progression-free survival (PFS) and overall survival (OS) were analyzed. A total of 148 patients were eligible for analysis. Patients with liver metastasis on initial diagnosis (n=19) had shorter PFS and OS than those without liver metastasis did (median of PFS, 6.7 vs. 11.2 months, p<0.0001; median of OS, 9.2 vs. 17.5 months, p<0.0001). Multivariable Cox regression analysis showed liver metastasis was an independent poor prognostic factor for PFS (HR=2.939 [95% CI: 1.729-4.997], p<0.0001) and OS (HR=3.300 [95% CI: 1.708-6.373], p=0.0004). Liver metastasis predicts poorer PFS and OS in stage IV lung adenocarcinoma patients with susceptible gene mutations receiving first-line gefitinib. Further study is warranted to elucidate the underlying mechanisms and find treatment modalities to improve prognosis of these patients.