Effect of Tumor Deposits on Overall Survival in Colorectal Cancer Patients with Regional Lymph Node Metastases

Objectives: The staging system of the International Union Against Cancer considers tumor deposits to be N1c in patients with no regional lymph node metastasis, but the significance of tumor deposits in patients with regional lymph node metastases is unclear. We investigated the effect of tumor deposits on overall survival in colorectal cancer patients with regional lymph node metastases. Patients and Methods: From 2000 to 2008, 551 patients underwent resections for colorectal cancer at our medical center. We excluded 87 patients who had distant metastases or had received neoadjuvant chemotherapy or radiotherapy from our study and statistically analyzed the remaining 464 patients. Results: Stepwise multivariate Cox proportional hazards analysis in patients with regional lymph node metastases showed only tumor deposits to be significant for overall survival (hazard ratio: 2.813; P = 0.0002). Recurrence was seen in 49.2% of patients with tumor deposits (30/61) compared with 14.4% of patients without them (58/403; P < 0.0001). Tumor deposits did not show the same effect on overall survival as lymph node metastases. Conclusions: Tumor deposits were significantly associated with poorer overall survival in colorectal cancer patients with regional lymph node metastases. The effect of tumor deposits on overall survival was between that of lymph node metastasis and distant metastasis.