The SCOT trial has helped researchers answer an important health question about bowel cancer treatment. Its results may change the way some bowel cancers are treated in the future.
The purpose of SCOT trial was to assess the efficacy of 12 weeks of adjuvant chemotherapy versus 24 weeks in reducing recurrence of colorectal cancer and improving survival in patients with colorectal cancer. The study also evaluated the effects of short term chemotherapy on toxicity and quality of life in colorectal cancer patients.
The purpose of SCOT trial is to assess the efficacy of 12 weeks of adjuvant chemotherapy versus 24 weeks in reducing recurrence of colorectal cancer and improving survival in patients with colorectal cancer. The study also aims to evaluate the effects of short term chemotherapy on toxicity and quality of life in colorectal cancer patients.
Colorectal (large bowel) cancer is the second leading cause of cancer in Australia. Surgery is a common treatment option to remove the disease in patients with early cancer where disease has not spread. However, even after surgery has completely removed localised cancer, there is a 40% to 50% risk of disease relapse for stage 3 tumours.
After curative surgery to remove localised colorectal cancer, combined chemotherapy treatment (usually 24 weeks of 5FU and oxaliplatin) is a current standard to prevent the disease from returning. However, this treatment is associated with increased toxicity and can be a financial burden for the patient. There have been previous, smaller studies which suggest that a shorter treatment timespan is a possible alternative, without compromising the effectiveness of the chemotherapy drugs. It is possible that 12 weeks of chemotherapy may be less toxic without being less effective. However, chemotherapy regimens of less than 24 weeks duration have not been adequately studied. The SCOT trial will determine whether 12 weeks of chemotherapy treatment is as effective and less toxic compared to the standard treatment of 24 weeks in reducing cancer recurrence. Eligible participants are stage 3 patients who have had surgery to remove all their bowel cancer. Patients will receive combination chemotherapy – of either oxaliplatin/5-FU or oxaliplatin/capecitabine – for a duration of 12 or 24 weeks. There will be regular follow-up for up to 9 years to determine if the participants are disease-free and to assess overall survival, toxicity, cost effectiveness and quality of life.
If successful, the SCOT trial has the potential to significantly minimise the short and long-term side effects of chemotherapy.
To find out more about this trial
Available online at the Australian New Zealand Clinical Trial Registry (ANZCTR) here.
Short Course Oncology Therapy (SCOT) – A Study of adjuvant chemotherapy in colorectal cancer.
Conference Presentation Reference
- Iveson T, Kerr R, Saunders MP, Hollander NH, Tabernero J, Haydon AM, Glimelius B, Harkin A, Scudder C, Boyd K, Waterston AM, Medley LC, Wilson C, Ellis R, Essapen S, Dhadda AD, Harrison M, Falk S, Raouf S, Paul J. Final DFS results of the SCOT study: an international phase III randomised (1:1) non-inferiority trial comparing 3 versus 6 months of oxaliplatin based adjuvant chemotherapy for colorectal cancer. American Society of Clinical Oncology; 2–6 Jun 2017; Chicago.
- Shi Q, Sobrero AF, Shields AF, Yoshino T, Paul J, Taieb J, Sougklakos I, Kerr R, Labianca R, Meyerhardt JA, Bonnetain F, Watanabe T, Boukovinas I, Renfro LA, Grothey A, Niedzwiecki D, Torri V, Andre T, Sargent DJ, Iveson T. Prospective pooled analysis of six phase III trials investigating duration of adjuvant (adjuv) oxaliplatin-based therapy (3 vs 6 months) for patients (pts) with stage III colon cancer (CC): The IDEA (International Duration Evaluation of Adjuvant chemotherapy) collaboration. American Society of Clinical Oncology Annual Meeting; 2–6 Jun 2017; Chicago.
- Paul J, Briggs A, Harkin A, Haydon AM, Iveson T, Masterson M, Midgley RA, Cassidy J. SCOT: Short Course Oncology Therapy—A comparison of 12 and 24 weeks of adjuvant chemotherapy in colorectal cancer. Journal of Clinical Oncology 2011; 29 (suppl.). Abstract e14145.
- Haydon A, Price T, Jefford M, Walpole E, Yip D, Ransom D, Jeffery M, Tebbutt N, Wong N, Wollin B, Segelov E. SCOT: Short Course Oncology Therapy—a study of adjuvant chemotherapy in colorectal cancer. Clinical Oncological Society of Australia (COSA) Annual Scientific Meeting; 9–11 Nov 2010; Melbourne.
- Segelov E, Haydon A, Price T, Jefford M, Walpole E, Yip D, Ransom D, Jeffery M, Tebbutt N, Wong N. SCOT: short course oncology therapy— a study of adjuvant chemotherapy in colorectal cancer. Clinical Oncological Society of Australia (COSA) Annual Scientific Meeting; 9–11 Nov 2010; Melbourne. Asia-Pacific Journal of Clinical Oncology 2010; 6(suppl 3): 181. Abstract 289.
The primary objective of SCOT trial is to assess the efficacy of 12 weeks of adjuvant chemotherapy versus 24 weeks in terms of 3-year disease free survival. Secondary objectives include assessing overall survival, comparison of the cost effectiveness of the two treatment arms, toxicity and quality of life.
Colorectal (large bowel) cancer is the second most commonly diagnosed cancer in Australia. It is estimated that there will be over 16,000 new cases of colorectal cancer diagnosed in 2017.
Despite complete surgical resection of localised disease, there is still a 40% to 50% chance of disease relapse. Combined chemotherapy post-surgery is the standard of care for patients to reduce the incidence of cancer recurrence. Previous phase III studies have demonstrated the increased efficacy of incorporating oxaliplatin into the adjuvant treatment of colon cancer (MOSAIC and C-07) and have established 24 weeks of 5FU and oxaliplatin as the current standard for stage III colon cancer.
However, this treatment has been associated with increased toxicity (compared to 5FU based regimens); more specifically, potentially long-lasting neurotoxicity. In addition, the longer timeframe also results in greater financial burden on the patient. Small studies suggest that chemotherapy regimens of less than 24 weeks may be less toxic but still retain effectiveness in preventing disease relapse. However, this has not been adequately studied.
The aim of SCOT trial is to evaluate the safety and efficacy of adjuvant chemotherapy (FOLFOX: oxaliplatin/5-FU or XELOX: oxaliplatin/capecitabine) for 12 weeks versus 24 weeks in reducing cancer recurrence in patients with stage III or high-risk stage II colorectal cancer. In addition, if SCOT can establish equivalent efficacy with a shortened duration of adjuvant treatment, it will significantly reduce the financial burden for the patient and produce vast benefits in terms of short and long-term morbidity associated with treatment.
Clinical Trial Design
SCOT is an international, multicentre open-label randomised, two arm, phase III non-inferiority trial. 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 Australasia, the study is being sponsored by the AGITG and coordinated by the NHMRC Clinical Trials Centre.
Eligible participants in this trial will be allocated randomly to one of the two groups. Both groups will be receiving combination chemotherapy of either oxapliplatin/5-FU or oxaliplatin/capecitabine. The choice of combination chemotherapy will be decided by the participant’s medical practitioner.
Participants in one group will undergo chemotherapy for 12 weeks. Participants in the other group will undergo chemotherapy for 24 weeks.
The study participants will be regularly assessed for a period of up to 9 years to determine disease free survival, overall survival, toxicity, cost effectiveness and quality of life. During this period they will have study assessments which includes, clinical examination, carcinoembryonic Antigen test, computed tomography (CT) scans, evaluation of toxicity through physical evaluation and patient reports.
The trial results were presented at ASCO 2017. The abstract and oral presentation at ASCO 2017 showed that 3 months of adjuvant chemotherapy was non-inferior to 6 months of chemotherapy for patients with high risk stage II or stage III colorectal cancer; however the non-inferiority was only demonstrated with CAPOX regimen and not FOLFOX.
Dr. Andrew Haydon (The Alfred Hospital, Melbourne VIC)
Professor Eva Segelov (Monash Health, Monash University VIC)
Dr. Andrew Haydon
Available online at the Australian New Zealand Clinical Trial Registry (ANZCTR) here.