LAUSR

135Background: Medical management of advanced GC is mostly dependent on prognostic assessment based on tumor stage (TNM) and clinical patients (pts)’ characteristics, other than HER2 expression. Prognostic and predictive factors are clearly needed, and histotype could be proposed as a surrogate marker of disease biology. Methods: We retrospectively analyzed pts with advanced GC treated with first line chemotherapy (CT) at Oncology Unit of Humanitas Gavazzeni (Bergamo) and Policlinico Gemelli (Roma). Pts were divided in three subgroups according to histological diagnosis: diffuse type carcinoma, intestinal type carcinoma and signet ring cell carcinoma. HER2 positive tumors were excluded from the analysis. The aim of our analysis was to compare clinical outcomes of metastatic GC pts receiving first line CT according to histological classification (overall survival: OS and Progression Free Survival: PFS). Results: We analyzed 170 pts. Histological diagnosis was as follows: 24.1% (n=41) signet ring cell, 54.4...