New study to gauge workplace cancer in Ontario

New study to gauge workplace cancer in Ontario
An asbestos removal worker prepares for a job
A groundbreaking study being conducted by the Occupational Cancer Research Centre is looking to determine the prevalance of work-related cancer in Canada. The study will look at the effect of workplace cancer on workers as well as the system in hopes of establishing future preventive measures.

The Occupational Cancer Research Centre (OCRC) is embarking on a study to determine how many work-related cancers occur in Ontario and Canada. The study — the first of its kind for these regions — will look at the burden of occupational cancer (i.e., its impact on humans, including death, sickness and lost time), as well its economic costs. In addition, it will help to determine which prevention activities will have the most impact in the future.

The study was launched during OCRC’s annual Research Day on March 23. The event highlighted previous international studies on the burden of occupational cancer, and provided updates on some of the centre’s ongoing studies.

Previous studies
In the last 10 years, there have been a number of studies worldwide estimating the burden of occupational cancer — a 2001 Finnish study estimated that eight percent of cancer deaths are attributable to workplace exposures, compared to 2.4 to 4.8 percent found in a 2003 U.S. study, and 5.3 percent in a 2010 U.K. study.

Men were found to have much higher proportions of work-related cancer than women (8.2 percent among men and 2.3 percent among women in the U.K. study); however, much less research has been done on occupational cancer among women.

The results from these studies varied, not just because of differences in industries and exposures in each country, but also because of differences in the number of carcinogens and cancer sites considered. All included carcinogens known to be associated with workplace exposure, but some also included probable human carcinogens (such as shiftwork).

Assessing Ontario’s burden
Like the international studies, the new Ontario/Canada study will use epidemiologic data and exposure studies to estimate the impact of work-related cancer. It hopes to emulate many of the features of the recent U.K. study, which “used a broader set of cancer sites and a broader set of carcinogens than any of the recent studies have,” says Paul Demers, OCRC’s director.

“If we follow the same general pattern as the U.K.,” notes Demers, who is also lead researcher on the study, “we’ve got a lot of advantages in that they’ve done much of the work. We can simply start where they left off, make this a more Canadian study by incorporating Canadian data — both Canadian epidemiological studies, but especially Canadian exposure data — and go on from there.”

The exposure data will come from Carex Canada, which comprises a multidisciplinary team of researchers based at the School of Environmental Health at the University of British Columbia. Carex is developing estimates of the number of Canadians exposed to known, probable and possible carcinogens in workplace and community environments.

There has been only one Canadian study published in recent years. A 2010 study in Alberta estimated that almost 10 percent of cancer deaths among men and 1.3 percent among women were work-related. That means that 2,700 Albertans currently live with occupational cancer, and 760 new occupational cancer cases can be expected each year.

The Alberta study also looked at the economic burden of these cancers. It estimated the direct medical cost to be $15.6 million, with an additional $64 million in lost economic resources and reduced productivity.

Demers says that OCRC will consider the methodology used in the Alberta study when looking at the economic burden in Ontario.  “That’s an area we’re still developing,” he notes. “I would say we’ll take elements from the Alberta study, but we’d calculate costs here in Ontario.”

One of the most exciting aspects of the new study, says Demers, is the possibility it holds for encouraging more aggressive prevention in the future.

“There are two goals of doing a project like this,” he says. “One is to raise awareness about the importance of occupational cancer, and the other is to promote prevention activities. The U.K. study used their data to project forward and say if certain prevention activities were undertaken, what kind of impact it would have on future cancers. That is something we’d like to incorporate, and will probably be adopting a similar model.”

If the predictions from the international and Alberta studies hold true in Ontario, an estimated 500 to 2,300 people will die of workplace cancer each year. Demers expects the study to take at least three years to complete, but anticipates that some results will be available after a year of work.

Priorities for the future
OCRC’s Research Day also featured an overview of some of the studies the centre is currently conducting, including those on: the effectiveness of asbestos-related interventions in reducing cancer rates; historical exposure to wood dust; mesothelioma in Ontario; and exposure to multiple pesticides and risk of non-Hodgkin lymphoma in Canadian men.

“Many of these studies are related to looking at the burden of workplace cancers,” says Demers. As a result, some of the data “will be incorporated into predicting what the current cancer burden is in Ontario.”

The day concluded with a summary of OCRC’s other cancer research priorities, which will focus on:
• suspected carcinogens to contribute to the classification of carcinogens;
• new and emerging issues (e.g., shiftwork), and under-studied populations (e.g., women);
• new groups at increased risk and new potential carcinogens; and
• established carcinogens for exposure surveillance and prevention-related research.

The OCRC, based in Cancer Care Ontario, was established in 2009 to fill gaps in the knowledge of work-related cancers and to use its findings to inform preventive programs and improve the health of workers. To find out more about the new study and other research at OCRC, visit