To compare the efficacy of tegafur/uracil (UFT) plus folinate calcium (leucovorin: LV) administered orally and UFT plus Krestin (PSK) administered orally enrolling patients with pTNM stage IIB or III colorectal cancer as subjects in a multicenter collaborative randomized open-label comparative controlled study and consequently to determine the usefulness of the above regimens as adjuvant therapy after surgery.

To compare the efficacy of tegafur/uracil (UFT) plus folinate calcium (leucovorin: LV) administered orally and UFT plus Krestin (PSK) administered orally enrolling patients with pTNM stage IIB or III (UICC Sixth version) colorectal cancer/histological curability A (Japanese Classification of Colorectal Carcinoma, Sixth version) as subjects in a multicenter collaborative randomized open-label comparative controlled study and consequently to determine the usefulness of the above regimens as adjuvant therapy after surgery.

Inclusion Criteria:

• Patients with pTNM stage IIB or III (UICC Sixth version) primary colon cancer/rectal cancer who have undergone surgery of histological curability A (including laparoscopic surgery) (the curability is judged after surgery)
• Patients with primary tumor that directly invades other organs or structures and/or perforates into the visceral peritoneum (T4) or with histologically positive lymph node metastasis (N+) (to be judged after surgery)
• Patients who is between 20 and 80 years old at the time of obtaining informed consent
• Patients with performance status of 0 - 2
• Patients without receiving any cancer treatment such as radiation, chemotherapy, and immunotherapy before surgical operation
• Patients without severe dysfunction of renal, hepatic, or bone marrow function
• Patients without serious complications such as bone marrow suppression, diarrhea, and infections diseases
• Patients who have given consent to participate in this clinical study by himself/herself or his/her family

Exclusion Criteria:

• Patients in whom the bottom of tumor reaches the peritoneal reflection
• Patients with lower rectal cancer (Rb), anal canal (P), or circumanal skin (E)
• Patients who has active multiple cancers or whose disease-free survival is less than 5 years even though the cancers are metachronous (except carcinoma in situ and skin cancers)
• Women who are currently pregnant or wish to be pregnant during this clinical study
• Patients who are judged to be inappropriate to participate in this clinical study by the investigator or subinvestigator