Long-term effect of 5-fluorouracil enhanced by intermittent administration of polysaccharide K after curative resection of colon cancer - A randomized controlled trial for 7-year follow-up

Background and aims. The efficacy of a biological response modifier polysaccharide K in adjuvant immunochemotherapy was evaluated in primary colon cancer patients with macroscopic Dukes' C after curative resection. Patients and methods. Employing the minimization method using three factors (lymph node metastases, preoperative serum CEA level, and institution), 446 patients were allocated into groups P and C. Group P received immunochemotherapy, oral PSK (3 g per day) followed by oral 5-FU (200 mg/body per day), while group C received only intermittent chemotherapy, oral 5-FU (200 mg per day) followed by 4-week rest. Both groups received ten courses. Results. Survival for cancer death was significantly higher in group P than in group C, but there was no difference in 7-year disease-free survival or overall survival had. Conclusion. Repeated alternating administration with PSK followed by 5-FU can improve survival for cancer death.