Prognostic Significance Of The Novel Iaslc Classification In Resected Pn0 Long Adenocarcinomas

e22113 Background: The aim of this study is to validate impact of tumor architecture defined according to the novel IASLC/ATS/ERS classification on patient overall survival (OS) in resected pN0 invasive pulmonary adenocarcinomas. Methods: We identified patients who underwent resection of pN0 adenocarcinoma from 1998 to 2008 in our institution. Two pathologists, blinded to patient outcome, independently performed histopathologic subtyping according to IASLC/ATS/ERS classification. Histomorphologic data were correlated with patient outcome. Kaplan-Meier curves were used to calculate 5-year survival. Univariate and multivariate analysis were undertaken to control prognostic factors. The following variables were included in the univariate analysis: Sica grade and patterns, pathological 7th edition TNM stage, pleural invasion, lymphatic invasion, vascular invasion, peritumoral lymphocytic infiltrate, -cell type and tumor diameter. Multivariate analysis was used for variables that were found to be significant in the univariate analysis. Results: Sixty-six patients were studied; median age 65 ys (48-84), 71% male. 29 patients (43%) were staged as I, 25 (37%) as II and 12 (18%) as IIIA. Median follow up was 53 months (range: 3-146). Five mutually exclusive tumor histology pattern groups were identified: solid (30,3%), papillary (18,18%), lepidic (3,03%), acinar (43,9%) and mucinous (4,55%). Solid pattern tumors were associated with a lower OS (median: 21 months) than nonsolid pattern tumors(median: 66 months). At univariate analysis, UICC stage (p < 0.001), T (p<0.001), Sica score (p=0.042), Sica primary pattern (0.030) and lymphocytic infiltrate (p=0.001) were related to shorter OS. The predominant growth pattern (p= 0.051), the cell type (p= 0.134) and the other variables were not associated with OS. Multivariate analysis confirmed Sica patterns as an independent prognostic marker of shorter OS (p = 0.044), together with stage and T. Conclusions: Our data confirm the role of known prognostic factors, such as UICC stage and T, as predictor of survival in pN0 patients and suggest the relevance of architectural pattern according to Sica as an efficient new prognostic factor.