In a Korean retrospective study reported in JAMA Network Open, Bong et al found that the addition of oxaliplatin to fluoropyrimidine-based adjuvant chemotherapy was associated with an overall survival benefit in patients with stage III colorectal cancer aged ≤ 70 years but not in those aged > 70 years. No benefit of the addition of oxaliplatin was observed among patients with stage II disease.
Study Details
The study involved data on patients aged 60 to 80 years from the Korea Health Insurance Review and Assessment Service who received treatment between January 2014 and December 2016. Patients were followed until death or end of April 2024. The primary outcome measure was overall survival.
Key Findings
Among 8,561 patients included in the analysis, 2,913 (34.0%) had stage II disease and 5,648 (65.9%) had stage III disease. Among 3,915 aged ≤ 70 years, 352 (8.9%) received nonoxaliplatin treatment; among 1,717 aged > 70 years, 662 (38.6%) received nonoxaliplatin treatment.
Among patients with stage II disease, adjusted analysis showed that the addition of oxaliplatin was not associated with a significant effect on overall survival among patients aged ≤ 70 years (adjusted hazard ratio [HR] = 0.71, 95% confidence interval [CI] = 0.34–1.50) or > 70 years (adjusted HR = 1.09, 95% CI = 0.73–1.64).
Among patients with stage III disease, adjusted analysis showed that the addition of oxaliplatin was associated with significantly improved survival among patients aged ≤ 70 years (adjusted HR = 0.59, 95% CI = 0.46–0.77, P < .001), with 5-year overall survival rates of 84.8% in the oxaliplatin group vs 78.1% in the nonoxaliplatin group (P = .003). No significant association with survival was observed in patients aged > 70 years (adjusted HR = 0.85, 95% CI = 0.67–1.07, P = .18).
Oxaliplatin use was significantly associated with chemotherapy discontinuation in patients aged > 70 years with stage III disease (adjusted odds ratio [OR] = 1.55, 95% CI = 1.19–2.03, P = .001), but not in those aged ≤ 70 years (adjusted OR = 1.22, 95% CI = 0.93–1.62, P = .16).
The investigators concluded: “In this population-based cohort study, oxaliplatin addition was associated with significantly improved survival among patients with stage III colorectal cancer aged 70 years or younger but not in those older than 70 years. There was no association with improved survival among patients with stage II disease regardless of age. Moreover, in patients older than 70 years with stage III disease, oxaliplatin use was significantly associated with chemotherapy discontinuation.”
Seogsong Jeong, MD, PhD, of the Department of Biomedical Informatics, and Sanghee Kang, MD, PhD, of the Department of Surgery, Korea University Guro Hospital, Korea University College of Medicine, Seoul, are the corresponding authors for the JAMA Network Open article.
Disclosure: The study was supported by Korea University Guro Hospital, Institute of Information & Communications Technology Planning & Evaluation, and others. For full disclosures of all study authors, visit jamanetwork.com.
