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

Authors: Katsuki Ito, Hiroaki Nakazato, Akihiko Koike, Hiroshi Takagi, Shigetoyo Saji, Shozo Baba, Masayoshi Mai, Jun-ichi Sakamoto, Yasuo Ohashi

Journal: International Journal of Colorectal Disease

Study Design: Randomized, controlled trial

Participants: 446 patients with curatively resected colon cancer and macroscopic lymph node metastasis (Dukes’ C)

Trial Length: 7-year follow-up

Intervention:

• Group P (n = 220): Immunochemotherapy with oral PSK (3 g/day) for 4 weeks followed by oral 5-FU (200 mg/day) for 4 weeks, repeated for ten courses
• Group C (n = 221): Intermittent chemotherapy with oral 5-FU (200 mg/day) for 4 weeks followed by a 4-week rest, repeated for ten courses

Primary Outcomes: Overall survival (OS), disease-free survival (DFS), and survival for cancer-related death (SCD)Summary: The study investigated the long-term effect of adjuvant immunochemotherapy with PSK and 5-FU in patients with curatively resected colon cancer and lymph node metastasis. The results showed no significant difference in 7-year DFS or OS between the immunochemotherapy and chemotherapy groups. However, the immunochemotherapy group had significantly higher 7-year survival for cancer-related death (SCD) compared to the chemotherapy group (83.4% vs. 78.5%, P = 0.019). The study suggests that alternating administration of PSK and 5-FU may improve survival for cancer-related death in these patients.