471P Prognostic impact of lymphovascular invasion and C-MET overexpression in resected stage IB NSCLC

Abstract

Aim/Background: In stage IB non-small cell lung cancer (NSCLC), prognostic factor is not well known and administration of adjuvant treatment is controversial. The C-MET is known to be associated with the pathogenesis and progression of NSCLC. Our purpose was to evaluate the impact of clinicopathological characteristics and C-MET on recurrence free survival (RFS) and cancer-specific survival (CSS) in patients with stage IB NSCLC, undergoing surgical resection. Methods: From 2005 to 2013, 115 patients who underwent complete resection with pathological stage IB were enrolled. We retrospectively reviewed clinicopathological data and performed immunohistochemistry with anti-MET monoclonal antibody in tissue microarrays. RFS and CSS were evaluated in patients depending on clinicopathological factors and C-MET status. Results: The median age of 115 patients was 65 years (range: 32-82 years). The patients comprised of 78 men (68%) and 37 women (31%). The histological types were adenocarcinoma (n = 77), squamous cell carcinoma (n = 32), others (n = 6). Thirty four patients relapsed and twenty four died of cancer progression. On the univariate analysis, lymphovascular invasion (LVI) (P = .003) and C-MET overexpression (P = .014) were significantly associated with decreased RFS. Meanwhile, smoking (P = .029) and LVI (P = .040) were correlate with shortened CSS. C-MET overexpression (P = .130) were not associated with CSS. However, in larger tumor than median size (>3.5cm), C-MET overexpression (P = .039) had a relation with reduced CSS. In multivariate analysis, LVI (RFS: P = .017) and C-MET (RFS: P = 0.040) were negative independent prognostic factor for RFS, but not significant for CSS. Subgroup assessments according to LVI and C-MET co-positivity were performed with univariate and multivariate analyses. Co-presence of LVI and C-MET overexpression was a significant negative prognostic factor for CSS (P = .023) as well as RFS (P = .002) in resected stage IB NSCLC. Conclusions: Our data indicates that stage IB NSCLC patients with LVI and C-MET overexpression showed poor survival outcome and adjuvant chemotherapy should be strongly recommended for these patients, especially with co-presence of LVI and C-MET overexpression. Disclosure: All authors have declared no conflicts of interest.