Impact of epidermal growth factor receptor (EGFR) activating mutations and their targeted treatment in the prognosis of stage IV non-small cell lung cancer (NSCLC) patients harboring liver metastasis

Eduardo Castañón, Christian Rolfo, David Viñal, Inés López, Juan P Fusco, Marta Santisteban, Patricia Martin, Leire Zubiri, José I Echeveste, Ignacio Gil-Bazo

Liver metastases appear in 20-30% of patients diagnosed with non-small cell lung cancer (NSCLC) and represent a poor prognosis feature of NSCLC and a possibly more treatment-resistant condition. Potential clinical outcome differences in NSCLC patients with liver metastases harboring molecular alterations in EGFR, KRAS and EML4-ALK genes are still to be determined. This study aims to evaluate the incidence of liver metastasis in a single population and look for potential correlations between EGFR mutations, liver infiltration and clinical outcomes. A total of 236 consecutive stage IV NSCLC patients treated at the Clínica Universidad de Navarra were analyzed. At onset, liver metastases were present in 16.9% of patients conferring them a shorter overall survival (OS) compared to those with different metastatic locations excluding liver infiltration (10 vs. 21 months; p = 0.001). Patients with EGFR wild-type tumors receiving standard chemotherapy and showing no liver involvement presented a superior median OS compared to those with liver metastases (23 vs. 13 months; p = 0.001). Conversely, patients with EGFR-mutated tumors treated with EGFR tyrosin-kinase inhibitors (TKI's) presented no significant differences in OS regardless of liver involvement (median OS not reached vs. 25 months; p = 0.81). Overall, liver metastases at onset negatively impact OS of NSCLC patients. EGFR TKIs however, may reverse the effects of an initial negative prognosis of liver metastasis in first-line treatment of EGFR mutated NSCLC patients.