Prognostic Factors after Potentially Curative Resection in Stage II or III Colon Cancer

It is important to identify factors that are predictive of outcome after a curative resection in colon cancer in order to optimize adjuvant therapy. To investigate these prognostic factors we conducted a retrospective analysis of our clinicopathological data. A total of 190 patients with a pathological stage II or III colon cancer underwent potentially curative resection with lymphadenectomy at our hospital between 1990 and 1998. These patients received no preoperative chemotherapy, immunotherapy or radiotherapy. Postoperative adjuvant chemotherapy using oral fluoropyrimidines was performed in 127 patients, and the other 63 patients underwent surgery alone. Univariate and multivariate analyses for prognostic factors were carried out. The univariate analysis revealed that invasion to adjacent organs, N1-2, positive mesenteric lymph node metastasis (MLN+), lymphatic permeation (ly) 1-3, venous invasion (v) 1-3, and v2-3 were each significant factors indicating worse disease-free survival, and that N1-2, MLN+, ly1-3, v1-3 and v2-3 were each significant factors for worse overall survival. In the multivariate analysis, MLN+ and v1-3 were significant factors for worse disease-free survival, and for worse overall survival. In conclusion, stage II or III colon cancer patients positive for mesenteric lymph node metastasis or for venous invasion have a greater risk of recurrence and death after potentially curative resection. Postoperative adjuvant chemotherapy using oral fluoropyrimidines did not significantly reduce the risk of recurrence and death in these patients. More effective adjuvant chemotherapy than oral fluoropyrimidine should be considered, especially in such high-risk patients.