Survival Outcome in Early-Onset Metastatic Colorectal Cancer: A Multicenter-Matched Pair Analysis.

Introduction: Survival of patients suffering from metastatic colorectal cancer (mCRC) has increased over the last decades. These benefits appear to be restricted to patients aged 50 and above. However, among the population aged <50, colorectal cancer incidence and mortality rates are significantly rising. The clinical benefit of treatment in this population still is a matter of debate. We aim to compare the clinical outcome between patients aged 50 and younger.

Methods: In this retrospective, observational study, we analyzed data from 1,077 patients treated for mCRC at three cancer centers in Austria from January 2005 to December 2019. Patients were divided into two groups based on age at diagnosis: <50 years (eo-CRC) and >50 years (regular-onset CRC, ro-CRC). Propensity score matching was used to control for potential biases, and survival outcomes were compared between the two groups.

Results: The differences in tumor characteristics between eo-CRC and ro-CRC in the overall population were primarily related to tumor sidedness and disease-free survival following intended curative resection. Our data show that eo-CRC patients underwent metastases resection more often and received significantly more lines of treatment in the palliative setting. Overall survival was superior in eo-CRC compared to ro-CRC, even after adjusting for sidedness, timing of metastases, sex, number of treatment lines, and resection of metastases by propensity scoring.

Conclusion: Our study suggests that younger patients benefit at least to the same magnitude or even more from mCRC-treatment than patients aged 50 or above.