SCOT- Short Course Oncology Therapy - A study of Adjuvant Chemotherapy in colorectal ca by the CACTUS & QUASAR 3 Groups.

Lead Research Organisation: University of Glasgow
Department Name: College of Medical, Veterinary &Life Sci


Bowel cancer is a common disease. Most patients will have an operation to remove the cancer. Unfortunately the cancer will come back in 1 out of 2 patients. There is evidence to suggest that a 6-month course of chemotherapy can reduce the chance of the cancer coming back by killing the cancer cells that may have been left behind after surgery.
In the past, patients have received 6 months of chemotherapy treatment. Chemotherapy has side effects and many of these side effects get worse as the treatment goes on. There is some evidence that 3 months treatment provides the same benefit as 6 months, but this has never been directly compared. The aim of this study is to find out if 3 months of chemotherapy is just as effective as 6 months, with fewer side effects.
This study will enrol over 9000 patients from all over the UK. Half of the patients will receive chemotherapy for 6 months and half will receive chemotherapy for 3 months. We will be following these patients closely for many years to see if the effect of the two treatments is the same. We will also be looking at the side effects of the treatment and how this affects quality of life, and whether the cost of treatment is affected.
If this study does show that 3 months of treatment is as effective as 6 months it will lead to a major change in the way bowel cancer patients are treated in future. Treatment will be shorter with fewer side effects and will be more cost effective. This will be of enormous benefit to the individual patient, healthcare providers and society at large.

Technical Summary

Colorectal cancer is the second leading cause of cancer mortality in the UK. Following a complete surgical resection, patients face a 40-50% chance of disease relapse. Currently the standard adjuvant chemotherapy is six months of 5-flourouracil?based chemotherapy. Newer chemotherapy agents have increased the toxicity profile of chemotherapy in this disease.

The primary research objective of this trial is to ascertain whether three months of adjuvant treatment for colorectal cancer is as efficacious as six months of treatment. The secondary objectives are to assess the toxicity, economic and quality of life implications of shortening therapy. There is currently very limited evidence for reducing the duration of treatment, and therefore toxicity and cost.

This trial will be an open, randomised, controlled, multi-centre non-inferiority clinical trial. The outcomes measured will be disease?free survival, overall survival, cost-effectiveness, toxicity and quality of life.

The study incorporates a nested methodological sub-study addressing the question of the best time to randomise in non-inferiority studies aimed at reducing a standard treatment duration (before treatment starts or at the early stopping point), This substudy will run for the first 12 months of recruitment and also act as an internal pilot for the feasibility of the study as a whole.

It is proposed that a number of translational laboratory studies will run in parallel with this clinical trial.

Should this trial prove positive, it is likely that clinical practice worldwide will be significantly altered in line with the results. The potential benefit to patients, healthcare providers and society at large in terms of reduced toxicity and cost are far reaching.


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Grothey A (2018) Duration of Adjuvant Chemotherapy for Stage III Colon Cancer. in The New England journal of medicine

Description transSCOT - sample collection for translational studies in colorectal cancer
Amount £25,500 (GBP)
Funding ID C6716/A13941 
Organisation Cancer Research UK 
Sector Charity/Non Profit
Country United Kingdom
Start 01/2012 
End 03/2015
Title The 'Short Course Oncology Treatment' (SCOT) trial 
Description 6 months of oxaliplatin-containing chemotherapy is usually given as adjuvant treatment for stage 3 colorectal cancer. We investigated whether 3 months of oxaliplatin-containing chemotherapy would be non-inferior to the usual 6 months of treatment. Methods: The SCOT study was an international, randomised, phase 3, non-inferiority trial done at 244 centres. Patients aged 18 years or older with high-risk stage II and stage III colorectal cancer underwent central randomisation with minimisation for centre, choice of regimen, sex, disease site, N stage, T stage, and the starting dose of capecitabine. Patients were assigned (1:1) to receive 3 months or 6 months of adjuvant oxaliplatin-containing chemotherapy. The chemotherapy regimens could consist of CAPOX (capecitabine and oxaliplatin) or FOLFOX (bolus and infused fluorouracil with oxaliplatin). The regimen was selected before randomisation in accordance with choices of the patient and treating physician. The primary study endpoint was disease-free survival and the non-inferiority margin was a hazard ratio of 1·13. The primary analysis was done in the intention-to-treat population and safety was assessed in patients who started study treatment. This trial is registered with ISRCTN, number ISRCTN59757862. 
Type Of Material Database/Collection of data 
Year Produced 2019 
Provided To Others? Yes