PROGRESS IN THE EPIDEMIOLOGICAL UNDERSTANDING OF GENE- ENVIRONMENT INTERACTIONS IN MAJOR DISEASES: CANCER

Cancer epidemiology has undergone marked development since the nineteen-fifties. One of the most spectacular and specific contributions was the demonstration of the massive effect of smoking on the occurrence of lung, larynx and bladder cancer. Major chemical, physical and biological carcinogenic agents have been identified in the working environment and in the overall environment. The chain of events from environmental exposures to cancer requires hundreds of polymorphic genes coding for proteins involved in the transport and metabolism of xenobiotics, or in repair, or in an immune or inflammatory response. The multifactorial and multistage characteristics of cancer create the theoretical conditions for statistical interactions which have been exceptionnally detected. Over the last two decades, a considerable mass of data has been generated, mostly addressing the interactions between smoking and xenobiotic-metabolizing enzymes in smoking-related cancers. They are sometimes considered disappointing but they actually brought a lot of information and raised many methodological issues. In parallel, the number of polymorphisms which can be considered candidate per function increased so much that multiple testing has become a major issue, and genome wide screening approaches hav