"The environment has a real impact on the risk of cancer, although it remains difficult to assess": three questions for Professor Gérard Lasfargues, Managing Director General of the Science for Expertise Division

Despite medical advances, cancer remains the leading cause of death in France.  While active smoking, alcohol consumption and an unbalanced diet continue to be the main causes of cancer mortality, the environment has a real impact on the risk of cancer, although it remains difficult to assess.

Cancer and the environment, what are the research challenges?

Environmental factors play an important role in chronic diseases, including cancer. For example, according to WHO estimates, air pollution is responsible for one in six deaths worldwide, and 19% of cancers are due to environmental factors. Some carcinogens are now well known, such as asbestos, radon, cadmium, arsenic, airborne particles, ultraviolet rays and certain chemical pollutants. Others, such as certain pesticides or nanoparticles, are undergoing studies and research. One of the challenges in environmental health research is to establish causal links between certain cancers and exposure to chemical, physical or biological agents, on the basis of sound scientific knowledge. The methodological obstacles to be overcome are often related to difficulties measuring exposure, particularly low doses, and the sometimes very long time lags between exposure and onset of the disease. Assessing combined exposure – to several chemicals, for example – and the associated risks is a real scientific challenge. Many research programmes are currently examining this future challenge, as well as the question of the “exposome”, i.e. the totality of exposure to which an individual is subjected during their lifetime, regardless of the origin.

What about cancer related to occupational exposure?

Work-related cancers are also underestimated, as evidenced by the gap between data on occupational disease recognition and the estimated annual number of cancer cases (several thousand) in France. The data collected as part of the National Network for the Monitoring and Prevention of Occupational Diseases (RNV3P), which ANSES coordinates, tell us more about the industry sectors and occupations posing the greatest risk, but can also highlight new exposure situations or hazardous occupations. Thus, asbestos is incriminated in 42% of the cases of work-related cancers reported by the RNV3P, far ahead of polycyclic aromatic hydrocarbons (PAHs) (6.5% of cases). These cancers mainly affect people in metalworking and mechanical engineering occupations, or in construction.

What action is ANSES taking on these topics?

ANSES manages the funding for occupational health and environmental health research projects, to support advances in scientific knowledge in these areas. Each year, 6 to 8 million euros are mobilised as part of the National Research Programme on Environmental and Occupational Health (PNR EST). The funded projects contribute to the development of new knowledge, with the aim of better understanding the mechanisms of action of certain contaminants in cancer development. They also help to explore new avenues of research to prevent work-related or environmental cancers, one of the priorities of national cancer plans. To meet these challenges, ANSES also works closely with research players such as Aviesan and the National Cancer Institute (INCa), in order to combine synergies in the fight against cancer.