National cancer study launched
Cancer agencies launched a massive new study yesterday that aims to track 300,000 Canadians over two or three decades, potentially generating valuable new data on what causes the disease.
Unprecedented in size for this country, the project will conduct surveys and collect blood and other specimens from participants across the nation, trying to uncover the environmental, genetic and lifestyle factors that lead to various malignancies.
The number of research subjects equals the population of Victoria; the cost of simply signing them up is expected to reach $100-million.
“This could be a landmark study in Canada,” said Dr. Heather Bryant of the Canadian Partnership Against Cancer. “This has great potential to add to the understanding … Prevention research has been traditionally underfunded. This could really catalyze that area.”
The project is being spearheaded by five provincial cancer agencies and the federally funded Canadian Partnership, with federal and provincial governments picking up most of the initial $100-million cost.
Researchers aim to select the participants through random-dialing methods similar to those used by polling companies, ideally gathering a representative cross-section of the population, said Dr. Bryant.
Each subject will have to give a blood sample as well as saliva and toenail specimens, to be used in DNA and other testing. Researchers will ask them to complete questionnaires on their family histories, lifestyle and environment. Follow-up surveys are to be conducted periodically through the course of the research, Dr. Bryant said.
The cause of many cancers remains a mystery and scientists hope the project will generate clues to what triggers some of the illnesses, and point to measures that could be taken to prevent disease. Such longitudinal “cohort” studies are the gold-standard of cancer-prevention research, as opposed to those that look back at what factors might have caused or prevented cancer, relying on subjects’ often faulty memories.
A similar American Cancer Society project in the 1950s, for instance, offered up the most convincing evidence to date that tobacco smoking was linked to lung cancer, said Dr. Alpa Patel, who heads a new cancer society study, involving 500,000 subjects in the U. S.
“You’re not giving people a pill to take, you’re not intervening in how these people normally live their lives,” she said. “What you’re doing is observing how people live their lives, and from that seeing what is detrimental or beneficial.”
As well as the U. S. study, similar research has been launched recently in the U. K. and Europe, each with 500,000 recruits. The Canadian project is far from redundant, however, said Dr. Patel. Replication of results to ensure they are accurate is “essential” in medical science, and findings are sure to be compared among the different cohorts, she said.
The genesis for the Canadian study was a pilot project launched in Alberta in 2000, which has now enrolled 30,000 subjects. Large cohort studies often involve specific, motivated groups, such as nurses or doctors. Canadian experts wanted more of a cross-section, but debated initially whether so many people contacted without their initial consent would participate, recalled Dr. Paula Robson, who is leading the research in Alberta.
“It’s a bit of an odd request for people to get,” she said.
Nevertheless, about 30% of those called agreed to take part, and, of those, more than 90% were still involved three years later. They included Mary O’Neill, a former Conservative MLA whose own father died from cancer and says she was happy to participate.
Source : nationalpost.com