Prognostic impact of baseline CEA level and surgery of primary tumor among patients with stage IV denovo colon cancer.

503 Background: Surgical resection of primary tumor among pts with stageIV denovo colorectal cancer is controversial. Prognostic role of baseline CEA level in the same cohort has yet to be defined. The objective of this study was to determine the prognostic value of CEA and surgical resection of primary tumor among pts with stage IV denovo colorectal cancer in the era of biologic therapy and to determine subgroups with improved survival outcome. Methods: The Surveillance, Epidemiology and End Results Registry was searched to identify patients with stage IV denovo colorectal cancer diagnosed between 2004-2007. Colorectal cancer specific survival (CCS) was estimated using the Kaplan-Meier product limit method. Cox models were fitted to assess the multivariable relationship of various pt and tumor characteristics and CCS. Results: 19,437 pts were identified with stage IV denovo colorectal cancer. Median CCS was 15M. Median CCS among pts with primary tumor removed was 20M vs 8M (primary intact; p<0.001). Medi...