Disease-Free Survival Versus Overall Survival As a Primary End Point for Adjuvant Colon Cancer Studies: Individual Patient Data From 20,898 Patients on 18 Randomized Trials

Abstract

Purpose A traditional end point for colon adjuvant clinical trials is overall survival (OS), with 5 years demonstrating adequate follow-up. A shorter-term end point providing convincing evidence to allow treatment comparisons could significantly speed the translation of advances into practice. Methods Individual patient data were pooled from 18 randomized phase III colon cancer adjuvant clinical trials. Trials included 43 arms, with a pooled sample size of 20,898 patients. The primary hypothesis was that disease-free survival (DFS), with 3 years of follow-up, is an appropriate primary end point to replace OS with 5 years of follow-up. Results The recurrence rates for years 1 through 5 were 12%, 14%, 8%, 5%, and 3%, respectively. Median time from recurrence to death was 12 months. Eighty percent of recurrences were in the first 3 years; 91% of patients with recurrence by 3 years died before 5 years. Correlation between 3-year DFS and 5-year OS was 0.89. Comparing control versus experimental arms within eac...