Tumor deposit is a poor prognostic indicator in patients who underwent simultaneous resection for synchronous colorectal liver metastases

BACKGROUND Tumor deposits are one of the important influencing factors among the different editions of Tumor, Node, Metastasis classification. Incidence and prognosis of tumor deposits in stage I, II, and III colorectal cancer patients has been explored. The aim of this study was to determine the prognostic value of tumor deposits in stage IV colorectal cancer patients who underwent simultaneous resection for synchronous colorectal liver metastases (SCRLM). METHODS Clinicopathological and outcome data of 146 consecutive SCRLM patients who underwent simultaneous R0 resection between July 2003 and July 2013 were collected from our prospectively established SCRLM database. The prognostic value of tumor deposits was evaluated by Kaplan-Meier and Cox regression analysis. RESULTS Tumor deposits were detected in 41.8% (61/146) of these SCRLM patients. Tumor deposits were significantly correlated with lymph node metastasis and nerve invasion of the primary tumors (P=0.002, P=0.041; respectively). The Kaplan-Meier survival analysis revealed that the overall survival (OS) and disease-free survival (DFS) of SCRLM patients with tumor deposits were significantly poorer than those with no tumor deposits (P=0.039, P=0.001; respectively). And with multivariate analysis, we found that positive tumor deposits were significantly associated with shorter DFS independent of lymph node status (P=0.002). Subgroup analysis found that of the 57 SCRLM patients with negative lymph node status, the OS and DFS of patients with positive tumor deposits were significantly shorter than those with negative tumor deposits (P=0.002 and P=0.031, respectively). Of the 89 patients with positive lymph node status, the OS of patients with tumor deposits was not significantly different than those without tumor deposits (P=0.965); however, the DFS of patients with tumor deposits was significantly shorter than those with no tumor deposits (P=0.034). CONCLUSION Tumor deposits may be an independent adverse prognostic factor in SCRLM patients who underwent simultaneous R0 resection.