EGFR-activating mutations and treatment with tyrosine-kinase inhibitors (TKI) to revert poor-prognosis (PP) associated with liver metastases (LM) in stage IV non-small cell lung cancer (NSCLC) patients (pts).

Abstract

e19106 Background: LM appear in 20-30% of pts diagnosed with NSCLC and they confer PP. However, whether the clinical outcome of NSCLC pts with LM harboring molecular alterations in EGFR, KRAS and EML4-ALK genes is substantially different depending on their distinct status is still unknown. Methods: A total of 268 consecutive stage IV NSCLC pts were included. The tumor molecular analysis for EGFR, KRAS and EML4-ALK was available in 205 pts (76.5%), 136 pts (50.7%) and 31 pts (11.6%), respectively. An EGFR mutation was observed in 32 pts (15.6%), KRAS was mutated in 28 pts (20.6%) and EML4-ALK gene rearrangement was observed in 3 pts (9.6%). We aimed to determine whether the molecular status of EGFR, KRAS and EML4-ALK has an impact on the clinical outcome of stage IV NSCLC pts. Results: Most of the pts were men (71.3%). The most common histology was adenocarcinoma (59.3%). Overall, 34% of the pts showed LM at any time of the disease course. Among the whole cohort, median OS for LM pts was 16 months vs 42 months for pts with metastases other than LM (p<0.001). Among pts with LM and EGFR mutations, the one-year survival rate was 85.7% vs 54.3% for pts with LM and EGFR wild-type (p=0.03). We analyzed whether pts received EGFR TKI or standard chemotherapy (SC). For the subgroup of pts carrying EGFR mutations and receiving TKI, the 18-month survival rate was 75% for those showing LM vs 80% (p=0.44) for those without LM. In contrast, for the subgroup of EGFR wild-type pts receiving SC, the 18-month survival rate was 32.4% for those showing LM vs 74.9% for those without LM (p<0.001). No impact of KRAS or EML4-ALK molecular alterations on OS of pts with LM was observed. Conclusions: The presence of LM at any time of the disease curse negatively impacts on the clinical outcome of NSCLC pts. However, the presence of EGFR activating mutations significantly improves the OS of those with liver spread, reaching a similar OS to subjects with no LM. Pts with EGFR mutations and LM may revert the PP associated to LM when an EGFR TKI is prescribed.