Adjuvant Immunochemotherapy with Oral Tegafur/Uracil Plus PSK in Patients with Stage II or III Colorectal Cancer: A Randomized Controlled Study  

Authors: S Ohwada, T Ikeya, T Yokomori, T Kusaba, T Roppongi, T Takahashi, S Nakamura, S Kakinuma, S Iwazaki, H Ishikawa, S Kawate, T Nakajima, and Y Morishita

Journal: British Journal of Cancer

Study Design: Randomized, controlled trial

Participants: 205 patients with curatively resected stage II or III colorectal cancer

Trial Length: 2 years of treatment with a 5-year follow-up

Intervention:

• PSK group (n = 137): 3 g PSK (protein-bound polysaccharide K) + 300 mg UFT (tegafur/uracil) orally daily for 2 years, following intravenous mitomycin C on postoperative days 1 and 2
  
• Control group (n = 68): 300 mg UFT orally daily for 2 years, following intravenous mitomycin C on postoperative days 1 and 2

Primary Outcomes: 5-year disease-free survival and overall survival

Summary: The study investigated the addition of oral PSK to UFT as adjuvant therapy for stage II or III colorectal cancer. The results demonstrated that the PSK group had significantly better 5-year disease-free survival (73.0% vs. 58.8%, P = 0.016) and a trend towards improved 5-year overall survival (81.8% vs. 72.1%, P = 0.056) compared to the control group. The benefit of PSK was particularly pronounced in stage III patients, with significant improvements in both disease-free and overall survival. PSK also appeared to reduce the risk of recurrence, especially lung metastases. The treatment was well-tolerated with minimal side effects. The findings suggest that adjuvant immunochemotherapy with oral PSK plus UFT is effective in improving outcomes for patients with stage II or III colorectal cancer, particularly those with stage III disease.