Guzzo Research Chair in Environment and Cancer of the Université de Montréal
Cancer is one of the most important health problems in Canada. Each year there are about 166,000 new cases of cancer and 74,000 deaths from cancer. Quebec suffers the highest rates of cancer in Canada. Nearly 40% of our citizens will get cancer during their lives and about three-quarters of us will be touched by cancer in the family. Among all causes of death, cancer is by far the most important determinant of premature death, leading to the greatest number of years of life lost. But cancer has an importance beyond the cold dry numbers; in the public imagination, there is no other disease that strikes the same chord of threat and fear.
Cancer treatment has gradually improved, but for most victims, a cancer diagnosis leads to suffering, anguish and sometimes death. The best hope we have to reduce the suffering caused by cancer is to prevent it. The best hope we have to prevent cancer is to identify and eliminate its causes. The causes of cancer can be categorized into those factors that we are born with and that make us susceptible to cancer (genetic factors) and those factors that we encounter throughout life that act to induce cancer or promote (environmental and lifestyle factors). At this time we are not able to modify our genes, but we can modify our environment.
It is estimated that we have the knowledge base to prevent nearly one-third of cancers by eliminating or mitigating known risk factors. The most important of these, by far, is cigarette smoking. Some of the other known human carcinogens that have been discovered by means of epidemiologic research include: asbestos, benzene, second-hand tobacco smoke, ionizing radiation in different forms, excessive sunlight, and others.
There are tens of thousands of chemicals to which humans may be exposed, either at work, at leisure, at home, in the community and through any medium (air, water, soil, food); they can be man-made or natural. For the vast majority of such agents, there is no evidence or sparse and inconclusive evidence of carcinogenicity, one way or the other. Examples of agents about which there is concern but no conclusive evidence include electromagnetic fields, cellular telephones, water chlorination by-products, pesticides, PCBs, dietary fat, breast implants, artificial sweeteners, diesel engine emissions, air pollution, and many other chemical and physical agents of the environment, and of our lifestyles. We really are dealing with a tip of an iceberg.
The main objective is to bring as much scientific evidence as possible to bear on the identification and characterization of the causes of cancer. The potential terrain for such research is vast, covering many types of cancer and an innumerable number of agents that we encounter in our lives. The problem calls for an epidemiologic approach, i.e. one that focuses on the exposures and diseases experienced by humans. But it also requires interaction with researchers in toxicology, experimental carcinogenesis, environmental measurement, and others. One important aim will to continue to establish large databases capable of assessing and highlighting many kinds of hazards. Another aim will be to seek research opportunities that arise because of some unique exposure circumstances or because of legitimate concerns expressed by citizens, government agencies or other groups.
Examples of investigations are:
- The possible causal relationship between 300 different chemicals found in the working environment (many of which are also found in the general environment) and risk of lung cancer; these include diesel exhaust, gasoline exhaust, acrylonitrile and formaldehyde, welding fumes, man-made mineral fibres, mineral oils, lead, nickel and other metal compounds, polycyclic aromatic hydrocarbons, inorganic acids and many more;
- The difference between men and women in their susceptibility to cancer risk posed by cigarette smoking;
- The cancer risks related to alcohol consumption;
- Cancer risks related to consumption of various foods and various non-alcoholic beverages;
- Physical activity and obesity as risk factors for cancer;
- Risk factors for prostate cancer, including occupational chemicals, and gene-environment interactions;
- Risk of brain cancer as a result of cellphone usage.
Documents (PDF)
