Background: Colorectal cancer (CRC) among younger patients is rapidly increasing globally. Many are diagnosed at an advanced stage, leading to poor outcomes, with 13% achieving long-term survival. Integrating systemic therapy with surgical resection, locally ablative therapies, and repeat multidisciplinary assessments has shown improved outcomes, as evidenced by the RAXO studies (1,2). We evaluated whether a similar approach can yield comparable outcomes in an Australian context.
Methods: We conducted a retrospective audit of patients diagnosed with metastatic CRC under the age of 55, treated in our practice from 2016, with a minimum follow-up of 18 months as of May 31, 2024. Data were collected from electronic medical records.
Results: 37 patients were eligible, with median follow-up of 48 months. Disease distribution was M1a (32%), M1b (49%), M1c (19%). Radical intent treatment was achieved in 65% of patients. Among these, the 4-year survival rate was 75%, with 89% of alive patients achieving minimal residual disease (MRD) or no evidence of disease (NED). Excellent survival outcomes were possible for both M1a and M1b patients with 4-year survival rates 78% and 84% and MRD/NED rates 88% and 90% respectively. Patients with RAS/RAF wild-type tumours had a 4-year survival of 75%, compared to 29% for those with either mutated tumours.
Conclusion: LMI integrating optimal systemic therapy, resection, and ablative therapies significantly improve long-term outcomes for younger patients with mCRC. They align well with the outcomes observed in the RAXO studies. Significant differences in outcomes are apparent between RAS/RAF wt vs. either mutated subgroups. Both M1a and M1b subgroups achieved exceptional survival outcomes. Intent and conversion were deliverable. This data highlight the importance of a comprehensive LMI strategy in managing mCRC in younger patients during the entire disease trajectory, suggesting that such an approach can be effectively implemented in different healthcare settings.