Introduction This article outlines the current Australian multidisciplinary treatment of synchronous metastatic colorectal adenocarcinoma and assesses the factors that influence patient outcome. Methods This is a retrospective analysis of the prospective ‘Treatment of Recurrent and Advanced Colorectal Cancer’ registry, describing the patient treatment pathway and documenting the extent of disease, resection of the colorectal primary and metastases, chemotherapy and biological therapy use. Cox regression models for progression-free and overall survival were constructed with a comprehensive set of clinical variables. Analysis was intentionn-ton-treat, quantifying the effect of treatment intent decided at the multidisciplinary team meeting (MDT). Results One thousand one hundred and nine patients presented with synchronous metastatic disease between July 2009 and November 2015. Median follow-up was 15.8 months; 4.4% (group 1) had already curative resections of primary and metastases prior to MDT, 22.2% (group 2) were considered curative but were referred to MDT for opinion and/or medical oncology treatment prior to resection and 70.2% were considered palliative at MDT (group 3). Overall, 83% received chemotherapy, 55% had their primary resected and 23% had their metastases resected; 13% of resections were synchronous, 20% were staged with primary resected first and 62% had only the colorectal primary managed surgically. Performance status, metastasis resection (R0 versus R1 versus R2 versus no resection), resection of the colorectal primary and treatment intent determined at MDT were the most significant factors for progression-free and overall survival. Conclusions This is the largest Australian series of synchronous metastatic colorectal adenocarcinoma and offers insight into the nature and utility of contemporary practice.
