Oxaliplatin Boosts Survival in Stage III CRC Only Up to 70 Years, Study Finds

Oxaliplatin-based adjuvant chemotherapy was associated with significantly improved survival but only in patients with colorectal cancer (CRC) aged 70 years or younger with stage III disease, according to one study.¹ No survival benefit was observed in patients aged more than 70 years or in those with stage II disease, and older patients receiving oxaliplatin were more likely to discontinue treatment.

Oxaliplatin use in older adults with CRC remains controversial.² Although adjuvant chemotherapy has improved outcomes overall, the benefits of adding oxaliplatin for patients aged 70 years and older are uncertain. Although some pooled trial analyses suggest survival benefits regardless of age, these come with increased toxicity, and the survival advantage appears diminished in older patients.

This population-based, retrospective cohort study is published in JAMA Network Open.¹

Study finds 70 years may be a key cutoff for oxaliplatin benefit in stage III colorectal cancer, with no survival advantage seen in older patients or those with stage II disease. | Image credit: siripimon2525 - stock.adobe.com

“This study found no association of oxaliplatin use with improved survival in patients older than 70 years,” wrote the researchers of the study. “This highlights the importance of refining age thresholds and incorporating geriatric assessments into treatment planning to identify patients who are likely to benefit from aggressive regimens.”

The researchers used data from the Korea Health Insurance Review and Assessment Service to examine outcomes among patients with stage II to III CRC who underwent curative surgery and received adjuvant chemotherapy between January 2014 and December 2016. Patients were followed until death or April 30, 2024. Researchers compared overall survival between those who received oxaliplatin-based chemotherapy and those treated with fluoropyrimidine alone.

To determine the optimal age cutoff for oxaliplatin benefit, age thresholds from 60 to 80 years were assessed. Additionally, the researchers evaluated the association between oxaliplatin use and chemotherapy discontinuation across age groups.

Among 8561 patients included in the study, 5648 (65.9%) had stage III CRC and 2913 (34.0%) had stage II disease. In patients with stage II cancer, oxaliplatin use was not associated with improved survival at any age threshold, with adjusted HRs (AHRs) ranging from 0.71 (95% CI, 0.34-1.50) to 1.09 (95% CI, 0.73-1.64). In contrast, for patients with stage III disease aged 70 years or younger, oxaliplatin was linked to significantly improved survival (AHR, 0.59; 95% CI, 0.4-0.77; P < .001), with a 5-year overall survival rate of 84.8% in the oxaliplatin group vs 78.1% in the nonoxaliplatin group (P = .003).

However, among those older than 70 years, oxaliplatin was not associated with improved survival (AHR, 0.85; 95% CI, 0.67-1.07; P = .18) and was linked to a higher risk of chemotherapy discontinuation (adjusted OR, 1.55; 95% CI, 1.19-2.03; P = .001).

However, the researchers acknowledged several limitations to the study, including potential selection bias and incomplete data. Additionally, a lower proportion of younger patients received nonoxaliplatin therapy, which may have affected results despite matching. The analysis also lacked molecular data, recurrence-free survival, and adverse event reporting, limiting insights into treatment tolerability, especially for older adults.

Despite these limitations, the researchers believe the study suggests an age cutoff of 70 years for oxaliplatin therapy among patients with stage III CRC.

“In patients with stage II disease, the lack of association between oxaliplatin and improved survival highlights the need for refined risk stratification to guide adjuvant therapy decisions,” wrote the researchers of the study. “Future research should continue to explore innovative approaches to optimize the treatment of older patients with colorectal cancer to ensure a balance between efficacy and safety.”

References

1. Bong JW, Lee H, Jeong S, et al. Older age threshold for oxaliplatin benefit in stage II to III colorectal cancer. JAMA Netw Open. 2025;8(8):e2525660. doi:10.1001/jamanetworkopen.2025.25660

2. Soveri LM, Lamminmäki A, Hänninen UA, et al. Long-term neuropathy and quality of life in colorectal cancer patients treated with oxaliplatin containing adjuvant chemotherapy. Acta Oncol. 2019;58(4):398-406. doi:10.1080/0284186X.2018.1556804