Adjuvant Chemotherapy With UFT/LV Versus UFT/LV Plus PSK in Stage II/III Colorectal Cancer

Uracil-tegafur+leucovorin (UFT/LV), an oral adjuvant therapy for stage II/III colorectal cancer, is non-inferior to standard weekly fluorouracil and folinate. Although polysaccharide K (PSK) has been evaluated as a postoperative adjuvant colorectal cancer drug, its efficacy remains unclear. This randomized phase II trial compared UFT/LV+PSK with UFT/LV as adjuvant chemotherapy.

Between April 2011 and August 2016, 186 patients who underwent radical resection randomly received 6 months of UFT/LV (Group A: 300 mg/m²/day UFT and 75 mg/day LV, every 35 days for five cycles), 6 months of UFT/LV+PSK (Group B: standard UFT/LV regimen and daily administration of 3 g/day of PSK), or 12 months of UFT/LV+PSK (Group C). The primary endpoint was the 3-year disease-free survival.

Groups A, B, and C consisted of 37, 75, and 74 patients, of which treatment was completed by 33 (89.2%), 63 (84.9%), and 53 (70.4%) patients, respectively (p=0.0279). Adverse event incidence for all grades were 59.5%, 52.1%, and 59.2%, and for grade ≥3 were 13.5%, 9.6%, and 9.9%, respectively. The 3-year disease-free survival rates were 72.5%, 82.2%, and 74.2%, respectively, with no significant differences. The preoperative lymphocyte ratio did not significantly differ between groups.

UFT/LV+PSK is comparable to UFT/LV therapy in terms of prognostic efficacy and reduced adverse effects. Thus, UFT/LV+PSK is a useful adjuvant chemotherapy option for patients with high-risk stage II/III colorectal cancer.