Colorectal cancer study - Charting the course

Some of the researchers involved in the third annual meeting of the Colorectal Cancer Interdisciplinary Research Team (L-R): Dr. Pat Parfrey, Angela Hyde, a MD/PHd student at Memorial, Dr. John McLaughlin, Dr. Michael Woods, who is helping to develop a new molecular-genetic laboratory focusing on colorectal cancer at MUN, Dr. Laurent Briollais, University of Toronto, and Alison Tucker, who did her B.Sc. at Memorial and is now pursuing a master’s degree at the University of Toronto.

More than 50 researchers involved in a multidisciplinary multi-site study of colorectal cancer held their third annual meeting at Memorial University July 5-7, 2004. The Colorectal Cancer Interdisciplinary Research Team, based at Memorial and the University of Toronto, has spent the last three years advancing the knowledge of the nature, effect and control of colorectal cancer. They are now planning for the future when the original five-year Canadian Institutes of Health Research grant of $5 million comes to an end. “We need to be setting goals and preparing applications for funding beyond 2005,” said Dr. John McLaughlin, principal investigator for the study at the University of Toronto. “We've done some excellent science and publication productivity is now our top priority. While there is no guarantee that CIHR funding for the entire project will continue, I am sure we can continue our research by funding individual projects.”

One Newfoundland study has looked at what proportion of people with colorectal cancer who live on the Avalon Peninsula of Newfoundland have an inherited form of the disease and what proportion have non-inherited colorectal cancer. Some patients with colorectal cancer have certain gene mutations called MLH1 and MSH2. Some of their family members may have also inherited these mutations. A similar study is being conducted in Ontario, and once all the information is collected the risk of developing colorectal cancer among the people who have the gene mutations will compared between Ontario and Newfoundland .

A keynote speaker at the colorectal cancer meeting was Dr. Polly Newcomb of the Fred Hutchinson Cancer Centre in Seattle . She spoke about colon cancer screening, which is extremely effective in the early detection and treatment of pre-cancerous lesions. The problem, she said, is that screening is not widely used. There are two effective screening tools – a sigmoidoscopy in which a flexible tube is inserted into the rectum to examine sections of the bowel or a colonoscopy which allows a physician to examine the whole colon.

Dr. Newcomb said both tests are effective in detecting and treating polyps, or pre-malignant lesions. But she said that only about one-third of people in the U.S. have had colorectal screening partly because of lack of knowledge and partly because the discomfort is felt to be too great. She said that maximizing the screening interval to sigmoidoscopy every five years and colonoscopy every 10 years would improve compliance and reduce costs.

Dr. Gail Eyseen spoke about lessons learned from colorectal polyp trials. Contrary to popular opinion, fibre and fat intake do not affect the number of polyps found, at least in the trial period of two to four years. The supplement that seemed to have the most effect on the number of polyps was calcium, and in trials with drugs it was found that aspirin also has a small protective effect.

Between large group sessions and small working groups, the management group of the Colorectal Cancer Interdisciplinary Research Team were pleased with the progress made at the July meeting. “Now we need to put together an action plan,” said Dr. Pat Parfrey, co-principal investigator of the study at Memorial. “By mid-fall we need the core parts of the grant application ready and we need eight to ten papers submitted within the next 12 months.”

One of the lasting benefits of the study is training graduate and postgraduate fellows. To highlight their research, the third annual meeting featured a student poster contest. First place went to Peter Campbell, a doctoral student at the University of Toronto, for his work on hormones and the risk of inherited colorectal cancer. Mr. Campbell spent a month last year doing part of his research at Memorial in the laboratory of Dr. Ban Younghusband, co-principal investigator of the project at MUN.

Second prize went to Jason Chaulk, a master's student at Memorial, for his work on methylation status of MLH1 in MSI colon tumors. And third place went to Roula Raptis, a doctoral student at U of T in molecular genetics and pathology.