Risk of hereditary form of bowel cancer: New preparation of omega-3 holds hope

A new preparation of an omega-3 polyunsaturated fatty acid found naturally in fish, offers hope for thousands of patients at risk of developing an inherited form of bowel cancer, a new study shows.

A team of investigators, led by Professor Mark Hull from the University of Leeds, studied patients diagnosed with a rare inherited condition called FAP (familial adenomatous polyposis), thought to be responsible for about one in every 100 bowel cancers.

Scientists observed a significant reduction in the size and number of pre-cancerous growths, known as polyps, during a six month trial of the omega-3 preparation.

Now Professor Hull and his team say that further research is needed to find out if this new agent, EPA (eicosapentaenoic acid) could help prevent the non-hereditary form of bowel cancer, which is the third most common cancer in the UK, diagnosed in around 37,000 people each year.

FAP causes a large number of polyps to form in the lining of the large bowel.  Patients usually undergo bowel surgery but remain at risk of developing polyps and cancer in any remaining bowel so that regular endoscopic (camera test) checks are required.      

Professor Hull said: "A safe and effective drug therapy may reduce the number of invasive check-up procedures, which can be unpleasant and always involve a small amount of risk.

"There is definitely a clinical need for an effective, preventative therapy that is both safe and well tolerated as the existing drug therapy for FAP can be associated with an increased risk of heart attack in older individuals," he added.  

The study, funded by SLA Pharma AG, was a collaboration between researchers at Leeds Institute of Molecular Medicine, St James's University Hospital, Leeds, St Mark's Hospital London, St George's Hospital, London and Sant'Orsola-Malpighi Hospital, Bologna.

During a randomised, placebo-controlled trial, the team observed the condition of 55 patients over six months. Twenty eight patients were given 2 grams daily of a new highly purified formulation of the omega-3 polyunsaturated fatty acid EPA (called Alfa). Researchers observed a significant reduction in the number and size of polyps in this group, whilst the placebo group showed an increase in polyp number and size over the same period.      

"The particular preparation of EPA that we used delivers approximately four times as much beneficial polyunsaturated fatty acid per day as is derived from eating two to three portions of fish a week.  The drug is also designed to be released into the small intestine, minimising nausea and halitosis often associated with taking over-the-counter fish oil supplements" said Professor Hull.

Further research is now needed to investigate whether the new preparation is a safe and effective treatment for the large number of patients who are found to have asymptomatic bowel polyps and who are at increased future risk of polyp recurrence and bowel cancer.

Around 85 per cent of people diagnosed with bowel cancer are over the age of 60. The Department of Health has introduced a screening programme for those aged between 60 and 75 and older people can request to be included through their GP.

http://www.limm.leeds.ac.uk/research_sections/molecular_gastroenterology/