South Australian Metastatic Colorectal Registry Research Articles

Prognostic Differences of RAS Mutations: Results from the South Australian Metastatic Colorectal Registry.

Effective targeting of RAS mutations has proven elusive until recently. Novel agents directly targeting KRAS G12C have shown promise in early-phase clinical trials that included patients with metastatic colorectal cancer. Prior reports have suggested that G12C mutation may be predictive of poor outcome. Assessment of the specific characteristics and prognostic implications of individual RAS mutation subtypes in patients with metastatic colorectal cancer. Retrospective review of individual RAS mutation types from the South Australian Metastatic Colorectal Registry between 2006 and 2020. Of the 5165 patients entered onto the registry, 2305 (45%) had RAS mutation results available. 772 (33%) had a RAS mutation. The nature of the RAS mutation was available in 668 (87% of those with RAS mutation). Rare mutations (outside codons 12 and 13) made up 12.6% of the total. There were numerical differences in survival between the specific RAS mutation subgroups, with the longest median overall survival (30 months) observed in those with G12S mutations. However, there was no statistical difference in survival when comparing the various RAS mutations, including the comparison of G12C to G12S (p=0.38). Patients with cancer harbouring rare RAS mutations had a median survival of 30 months. Whilst the G12S mutation was associated with the longest survival numerically, the observed survival for patients with the most common RAS mutations (G12C, G12V, G12A, G12D and G13D) did not significantly differ.

Is Survival for Patients with Resectable Lung Metastatic Colorectal Cancer Comparable to Those with Resectable Liver Disease? Results from the South Australian Metastatic Colorectal Registry.

Hepatic resection for colorectal (CRC) metastasis is considered a standard of care. Resection of metastasis isolated to lung also is considered potentially curable, although there is still some variation in recommendations. We explore outcomes for patients undergoing lung resection for mCRC, with the liver resection group as the comparator. South Australian (SA) metastatic CRC registry data were analysed to assess patient characteristics and survival outcomes for patients suitable for lung or liver resection. A total of 3241 patients are registered on the database to December 2014. One hundred two (3.1%) patients were able to undergo a lung resection compared with 420 (12.9%) who had a liver resection. Of the lung resection patients, 62 (61%) presented with lung disease only, 21% initially presented with liver disease only, 11% had both lung and liver, and 7% had brain or pelvic disease resection. Of these patients, 79% went straight to surgery without any neoadjuvant treatment and 34% had lung resection as the only intervention. Chemotherapy for metastatic disease was given more often to liver resection patients: 76.9 versus 53.9%, p=0.17. Median overall survival is 5.6years for liver resection and has not been reached for lung resection (hazard ratio 0.82, 95% confidence interval 0.54-1.24, p=0.33). Lung resection was undertaken in 3.1% of patients with mCRC in our registry. These data provide further support for long-term survival after lung resection in mCRC, survival that is at least comparable to those who undergo resection for liver metastasis in mCRC.