AIMS - The primary objective of the study is to assess the efficacy of 12 weeks of adjuvant oxaliplatin basedchemotherapy versus 24 weeks in terms of 3-year disease free survival (DFS). Secondary objectivesinclude assessing overall survival, comparison of the cost effectiveness of the two treatment arms, toxicityand quality of life.BACKGROUND - Colorectal cancer is the second leading cause of cancer mortality in Australia. In 2003there were approximately 12,536 new cases of colorectal cancer and 4,372 deaths from colorectal canceroverall. Following a complete surgical resection for localised disease, patients face up to a 40-50% chanceof disease relapse depending on the tumour stage. With the exception of a small proportion of patients whowill have disease amenable to further curative surgical resection, recurrence will lead to death.Clinical trials conducted throughout the late 1980s and early 1990s established adjuvant 5FU basedchemotherapy as the standard of care for resected stage III colon cancer and resulted in a relative reductionin mortality of around 30%. More recently, 2 phase III studies have demonstrated the increased efficacy ofincorporating oxaliplatin into the adjuvant treatment of colon cancer (MOSAIC and C-07) and haveestablished 24 weeks of 5FU and oxaliplatin as the current standard for stage III colon cancer. However, thisincreased efficacy is associated with increased toxicity (compared to 5FU based regimens), most importantlypotentially long-lasting neurotoxicity as well as a greater expense for the preferred oxaliplatin containingregimen. Small studies have suggested that 12 weeks of adjuvant 5FU based chemotherapy may be lesstoxic without being less effective, although adjuvant regimens of less than 24 weeks duration have not beenadequately studied and cannot be considered a standard of care at present.SCOT aims to definitively answer the question of whether 12 weeks of adjuvant chemotherapy(FOLFOX;oxaliplatin/5-FU or XELOX;oxaliplatin/capecitabine) is non-inferior to 24 weeks of the identicaltreatment in reducing cancer recurrence. In addition, if SCOT can establish equivalent efficacy with ashortened duration of adjuvant treatment, it will significantly decrease the financial burden of adjuvanttreatment on a population basis, and produce vast benefits in terms of short and long term morbidity.STUDY DESIGN - SCOT is an international, multicentre open-label randomised, two-arm, phase III noninferioritytrial. It is being coordinated internationally by the Cancer Clinical Trials Office Scotland (CaCTUS)and the Oncology Clinical Trials Office (OCTO) at the University of Oxford. In Australia and New Zealand(ANZ), the study is being sponsored by the AGITG and coordinated by the NHMRC Clinical Trials Centre.6000 patients will be recruited internationally, with 225 patients recruited from AGITG centres.STUDY PROGRESS - This study is funded by a Cancer Australia grant. The first site was opened torecruitment on 17th of March 2010. 32 sites are open in Australia and 5 open in New Zealand.To date, 199 patients have been recruited to the study from ANZ of the 5689 patients recruitedinternationally. The recruitment period of the study has been extended from end of March 2013 to end ofNovember 2013 in order to maximise the recruitment to the study.www.agitg.org.au Page | 41TRANSLATIONAL RESEARCH - All recruited trial patients at participating centres have the option of consenting to tissue donation. Tissue samples will be available for potential biological sub-studies plannedaround SCOT specifically.