In 103 patients without occult neoplastic cells (ONCs) in the lymph node sinuses, the 5-year relapse-free survival (RFS) rate and overall survival (OS) rate were 90.2% and 91.8%, respectively. In 21 patients with ONCs, the 5-year RFS and OS rates were 34.9% and 62.3%, respectively. There were marked differences of survival between the two groups (p=0.0000 and p=0.0003). In the primary tumors of the 21 ONC-positive patients, high and low TS levels were found in 46.2% (6/13) and 53.8% (7/13) of the recurrence group (n=13), respectively. High and low DPD levels were found in 23.1% (3/13) and 76.9% (10/13), respectively. In the non-recurrence group (n=8), high and low TS or DPD levels were found in 75.0% (6/8) and 25.0% (2/8) versus 12.5% (1/8) and 87.5% (7/8), respectively. The percentage of patients with high TS and low DPD levels was 23.1% (3/13) in the recurrence group and 62.5% (5/8) in the non-recurrence group (p=0.07). These results suggest that the presence of ONCs had a clear association with the 5-year RFS and OS rates. The recurrence group of ONC-positive patients with stage II/Dukes' B colorectal cancer was unlikely to be highly responsive to 5-FU-based treatment, thus requiring multi-combination chemotherapy using CPT-11 and/or L-OHP.