Identifying patients with T3-T4 node-negative colon cancer at high risk of recurrence.

PURPOSE: Adjuvant chemotherapy is effective for node-positive colon cancer patients. In node-negative patients, it could be justified in high-risk patients. The purpose of this study was to determine clinical and pathological findings associated with tumor recurrence in T3-T4 node-negative colon cancer patients.
METHODS: From 1974 to 1993, 108 patients undergoing colectomy for T3-4N0M0 colon cancer, without adjuvant chemotherapy, followed until death or for a minimum of five years, were divided into two groups: patients without recurrence (n = 74) and those dead from colon cancer or alive with recurrence (n = 34). Thirty-three clinical and pathological findings were studied.
RESULTS: In univariate analysis, the following were significantly associated with a high risk of tumor recurrence: male patients (P = 0.006), bowel obstruction (P < 0.001), weight loss >5 Kg (P = 0.03), circumferential tumor (P = 0.02), macroscopic or microscopic pericolic organ invasion (T4 stage; P < 0.001), perineural invasion (P = 0.02), vascular invasion (P = 0.045), poor tumor differentiation (P = 0.005), mesocolic invasion >1 cm (P = 0.009), less than 14 uninvolved nodes on the specimen (P = 0.03), and visceral peritoneal invasion (T4; P < 0.001). In multivariate analysis, the following were independent prognostic factors of recurrence: male patients (P = 0.005), bowel obstruction (P = 0.002), pericolic organ invasion (i.e., T4 tumor; P = 0.02), and less than 14 uninvolved nodes on a specimen (P = 0.01). On the other hand, preoperative carcinoembryonic antigen serum level, size and tumor location, blood transfusion, and mucin production were not associated with higher risk of tumor recurrence.
CONCLUSION: Our study identifies a subgroup of patients with node-negative colon cancer at high risk of recurrence, who could be included in priority trials of adjuvant chemotherapy.