Prognostic impact of tumor deposits in colorectal cancer with lymph nodes metastasis.

Abstract

e15051 Background:The TNM classification system was widely used in managing many kinds of cancer including colorectal cancer. However, there is one undefined aspect that is the value of tumor deposits (TDs) in the condition of TDs and lymph nodes metastasis (LNM) coexisting. This research aims to clarify the prognostic impact of TDs in colorectal cancer especially for the condition of TDs combined with LNM. Methods: An analysis was performed to evaluate the prognostic significance of TDs in stage Ⅰ to Ⅳ colorectal cancer patients from 2010 to 2013 using Surveillance Epidemiology and End Results (SEER) database as a training cohort (N = 65, 537). An additional 3, 719 patients from Fudan University Shanghai Cancer Center were enrolled between 2006 and 2014 as a test cohort to validate the results. Results: TDs were observed in 6.32% of patients in training cohort and 14.7% in test cohort. A significantly reduced overall survival was observed for TDs positive in LNM positive and negative colorectal cancer patients (hazard ratio [HR], 1.65; 95% CI, 1.54 to 1.76). Further analysis combining TDs with LNM shows that there is no considerable difference in the impact on overall survival between N1 and N1c or between N1 with TDs (N1TD) and N2. The 3-year survival rate was 82.3%, 72.0%, 69.9%, 55.7%, 52.1%, 39.4% for N0, N1, N1c, N1TD, N2 and N2 with TDs (N2TD) respectively. Similar results were observed in the test cohort. Conclusions: These results support the 7th and 8th TNM system in which N1c was integrated into pathological N classification. However, LNM with positive TDs should be also considered into the TNM classification system because of the high prognostic impact of TDs, which was not mentioned in the current TNM system.