Adjuvant Therapy With Protein-Bound Polysaccharide K and Tegafur Uracil in Patients With Stage II or III Colorectal Cancer: Randomized, Controlled Trial

Authors: Susumu Ohwada, M.D., Susumu Kawate, M.D., Toshiroh Ikeya, M.D., Tadahiro Yokomori, M.D., Teruo Kusaba, M.D., Takashi Roppongi, M.D., Toru Takahashi, M.D., Seiji Nakamura, M.D., Yoshiyuki Kawashima, M.D., Takashi Nakajima, M.D., Yasuo Morishita, M.D.

Journal: Diseases of the Colon & Rectum

Study Design: Prospective, randomized, controlled trial

Participants: 201 patients with curatively resected Stage II or III colorectal cancer

Trial Length: Median follow-up of 3.7 years

Intervention:

• PSK group (n = 134): Oral protein-bound polysaccharide K (3.0 g/day) plus oral tegafur/uracil (300 mg/day) for two years, following mitomycin C on postoperative Days 1 and 2
• Control group (n = 67): Oral tegafur/uracil (300 mg/day) for two years, following mitomycin C on postoperative Days 1 and 2

Primary Outcomes: Disease-free survival, overall survival, and recurrence ratesSummary: The study investigated the addition of oral protein-bound polysaccharide K (PSK) to oral tegafur/uracil (UFT) as adjuvant therapy for Stage II or III colorectal cancer. The results showed that the PSK group had a significantly better three-year disease-free survival rate (80.6%) compared to the control group (68.7%). The estimated relative risk of recurrence in the control group was 1.87 at three years. Although the three-year overall survival rate was higher in the PSK group (87.3%) compared to the control group (80.6%), this difference was not statistically significant. However, in patients with pathological TNM Stage III cancer, the three-year overall survival rate was significantly higher in the PSK group (83.0%) compared to the control group (59.3%). PSK also appeared to prevent distant metastases, particularly lung metastases. The incidence of adverse effects was minimal, and compliance was good. The study concludes that adjuvant therapy with PSK and UFT is highly effective in preventing recurrence and may increase overall survival in Stage III colorectal cancer.