Individual Abstract within a Delegate Designed Symposium 2025 Joint Meeting of the COSA ASM and IPOS Congress

Optimising outcomes in young-onset metastatic colorectal cancer from a multidisciplinary model of care (126634)

Prasad Cooray 1 2 , Ashleigh Poh 2 , Raffiela Garcia 2 , Caroline Le 2
  1. University of Melbourne, Melbourne
  2. Epworth Healthcare, Melbourne, VIC, Australia

Australia has the highest incidence of young-onset colorectal cancer (yo-CRC) globally (1). Many patients present with advanced-stage disease, contributing to poor outcomes. Contemporary survival data for young-onset metastatic colorectal cancer (yo-mCRC) is limited; the best estimates being a QLD study reporting a 5-year survival of 19% in yo-CRC versus 10% in older adults (2).

Building on our 2024 data demonstrating 5-year survival of 70% in selected yo-mCRC patients (3), we analysed a real-world cohort of mCRC patients (n=137) treated within out MDT model. All patients treated since 2016 with a minimum follow up of 3 years were included. The objective was to evaluate survival outcomes and the enablers of success in radical-intent management.

Treatment intent emerged as the strongest predictor of long-term outcomes. Of the 137 patients, five year survival of all treatable patients was 43% (56/131). Radical intent - defined as a multimodality strategy aiming for substantial remission/cure - was feasible in 53% of those >55 and 64% of patients aged <55. In this group, 5-year survival was 71.6% and 86.9% (estimated) respectively, demonstrating that outcomes comparable to leading international benchmarks are achievable in Australia (4,5).

Radical intent was maintained even in patients with unresectable disease, challenging the conventional dichotomy of resectable vs. non-resectable mCRC. Enablers of radical treatment included good performance status, ability to tolerate doublet/triplet chemotherapy ± biologics and absence of M1c disease. Molecular profile of RAS/RAF wild-type emerged as an independent favourable factor.

Radical-intent treatment is feasible in the majority of yo-mCRC patients and offers the potential for long-term survival and cure. Multimodality management with curative intent, even in technically unresectable cases, represents a critical strategy to improve outcomes. These findings highlight the urgent need for national visibility, early referral systems, and equitable access to curative-intent MDT pathways for young Australians living with metastatic colorectal cancer.

  1. Sung H, Siegel RL, Laversanne M, Jiang C, Morgan E, Zahwe M, et al. Colorectal cancer incidence trends in younger versus older adults: an analysis of population-based cancer registry data. Lancet Oncol. 2025;26(1):51–63. https:// doi. org/ 10. 1016/ S1470-2045(24) 00600-4
  2. Cao AMY, Lonne MLR, Clark DA. Long‐term survival outcomes in young‐onset colorectal cancer: A population‐based cohort study. Colorectal Dis. 2025 Feb;27(2):e70007. doi: 10.1111/codi.70007. Epub 2025 Jan 26. PMCID: PMC11876488.
  3. Cooray P, Poh A, Garcia R, Le c. Longitudinal multidisciplinary intervention (LMI) during the entire disease trajectory improves long-term outcomes in younger patients with metastatic colorectal cancer: A retrospective analysis in the Australian context. ASIA-PACIFIC JOURNAL OF CLINICAL ONCOLOGY Volume 20, Page148-149, Supplement 3, Meeting Abstract 284
  4. Osterlund P, Salminen T, Soveri LM, Kallio R, Kellokumpu I, Lamminmäki A, et al. Members of The RAXO study group are collaborators of this study and are listed in Appendix Table 4B. Repeated centralized multidisciplinary team assessment of resectability, clinical behavior, and outcomes in 1086 Finnish metastatic colorectal cancer patients (RAXO): A nationwide prospective intervention study. Lancet Reg Health Eur. 2021;29(3):100049. https:// doi. org/ 10. 1016/j. lanepe. 2021. 100049.
  5. Uutela A, Osterlund E, Halonen P, Kallio R, Ålgars A, Salminen T, et al. Resectability, conversion, metastasectomy and outcome according to RAS and BRAF status for metastatic colorectal cancer in the prospective RAXO study. Br J Cancer. 2022;127(4):686–94. https:// doi. org/ 10. 1038/ s41416- 022- 01858-8