The Japanese ACTS-CC 02 trial, designed to establish the superiority of adjuvant treatment with S-1 plus oxaliplatin (SOX) over UFT (tegafur and uracil) plus leucovorin (LV) in patients with high-risk stage III colon cancer, failed to meet the primary endpoint.

The 3-year disease-free survival (DFS) rate was 62.7% with SOX versus 60.6% with UFT/LV (HR 0.90, 95% CI [0.74, 1.09]; p = 0.28). Oral fluoropyrimidine regimens, such as those containing UFT or S-1, are favored in Japan due to their convenience. S-1 consists of tegafur (a prodrug of 5-fluorouracil [5-FU]) and two biomodulators, gimeracil and oteracil potassium. Gimeracil is a stronger suppressor of 5-FU degradation than uracil, and oteracil potassium helps to reduce gastrointestinal toxicity.

The ACTS-CC trial previously showed that adjuvant S-1 was noninferior to UFT/LV in patients with stage III colon cancer based on 3-year DFS rates. The current trial, conducted at 260 institutions in Japan, sought to determine whether the addition of oxaliplatin to S-1 could further improve outcomes for patients at high risk for recurrence. A total of 966 patients who underwent curative resection of high-risk stage III colon cancer (any T, N2, or positive nodes around the origin of the feeding arteries) comprised the study population.

Although results for the overall ACTS-CC 02 population showed no significant difference in 3-year DFS between the adjuvant regimens, potential signals of enhanced activity were observed with SOX in patients with more advanced disease. For example, among patients with stage IIIC colon cancer, the 3-year DFS rate was 55.8% with SOX and 50.6% with UFT/LV (HR 0.82, 95% CI [0.63, 1.06]; p = 0.12). Moreover, in the subgroup of patients with N2b disease, the 3-year DFS rate was 54.7% with SOX and 46.0% with UFT/LV (HR 0.76, 95% CI [0.55, 1.05]; p = 0.10).

This article is the news of a study presented at the 2019 Gastrointestinal Cancers Symposium. Read the original here.