Extra nodular metastasis is a poor prognostic factor for overall survival in node-positive patients with colorectal cancer.

Abstract

Colorectal cancer (CRC) is the second leading cause for cancer-related death in industrialized nations. Nodal involvement has been identified as a relevant prognostic feature in CRC. Extra nodal metastasis (ENM) describes the spread of malignant cells beyond the nodal capsule. ENM is thought to be an independent risk factor for poor survival. This study examined ENM as an independent risk factor for poor overall survival in patients with node-positive CRC. Data from a prospectively maintained CRC database was retrospectively analyzed. Blinded slides of patients with stage III and IV CRC following radical surgical resection were re-examined for the presence of ENM. The effect of ENM on overall survival was examined using Kaplan-Meier curves. One hundred forty-seven cases with node-positive CRC (UICC stages III and IV) including 78 cases with ENM were included for analysis. ENM was seen in 60 patients with colon cancer (58.8%) and in 18 patients with rectal cancer (40%), p = 0.033. ENM-positive patients had a significantly higher odd for cancer-related death compared to ENM-negative patients ratio of [OR 0.44: 0.22-0.88, CI 95%, p = 0.021], p = 0.02. The median overall survival was significantly longer in patients without ENM, 51.0±33 vs. 30.5±42months, p = 0.02. Extra nodal metastasis is an independent prognostic factor in patients with node-positive colorectal cancer. Extra nodal metastasis is associated with high odds of tumor-related mortality and poor overall survival.