PURPOSE: Adjuvant chemotherapy is effective for node-positive colon cancer
patients. In node-negative patients, it could be justified in high-risk pat
ients. The purpose of this study was to determine clinical and pathological
findings associated with tumor recurrence in T3-T4 node-negative colon can
cer patients. METHODS: From 1974 to 1993, 108 patients undergoing colectomy
for T3-4N0M0 colon cancer, without adjuvant chemotherapy, followed until d
eath 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), circumferent
ial 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. th
e following were independent prognostic factors of recurrence: male patient
s (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 lev
el, size and tumor location, blood transfusion, and mucin production were n
ot associated with higher risk of tumor recurrence. CONCLUSION: Our study i
dentifies a subgroup of patients with node-negative colon cancer at high ri
sk of recurrence, who could be included in priority trials of adjuvant chem
otherapy.