Tumor deposit is a poor prognostic indicator for patients who have stage II and III colorectal cancer with fewer than 4 lymph node metastases but not for those with 4 or more.

Abstract

Extranodal tumor deposits are involved in TNM classification. However, it is uncertain whether a tumor deposit is a regular lymph node metastasis, and its prognostic significance in patients with stage II or III colorectal cancer remains to be established. This study aimed to determine the prognostic significance of tumor deposits for stage II and III colorectal cancer. This study is a retrospective review of clinicopathological data. This study was conducted at a tertiary care hospital/referral center in Japan. We reviewed the clinical course of 171 stage II and 173 stage III consecutive patients between January 1999 and December 2006. We examined the clinicopathological features of colorectal cancers with tumor deposits and calculated overall survival and recurrence-free survival of the patients according to the status of tumor deposits. The primary outcome was the impact of tumor deposits on patient survival. Thirty-five (10.2%) patients with colorectal cancers had tumor deposits in the pericolic and/or mesocolic region. Survival rates among the patients with tumor deposits were significantly lower than those without (5-year overall survival: 58.4% vs 81.0%, p < 0.0001; 5-year recurrence-free survival: 47.1% vs 73.4%, p < 0.0001). Tumor deposit was an independent prognostic factor for patients with colorectal cancer in multivariate analysis (overall survival: HR, 2.30; 95% CI, 1.26-4.04; p = 0.04; recurrence-free survival: HR, 2.42; 95% CI, 1.04-4.90; p = 0.04). Tumor deposit was an independent prognostic factor in N0 and N1 colorectal cancer, whereas N2 cancer had poor survival outcome regardless of tumor deposit. Our study was a single-institution retrospective study, and the numbers of patients were relatively small to draw firm conclusions. Tumor deposit may be an independent adverse prognostic factor for stage II and III N1 colorectal cancer.