During this thirtieth campaign of Pink October, the Network Eenvironment Sante (RES) organized a conference in this 22 october 2024 in Paris titled « Cancer of Being 2050“. A unique event allowing us to take stock on involvement environmental factors in the occurrence you cancer you sein.
An increase of the incidence of breast cancer
According to the International Agency for Research on Cancer (Circ), the French female population is the most affected in the world by breast cancer. It is the leading cause of cancer death in women.
Between 2022 and 2050 (in France), experts predict a increase in’environ 13% of the number of proven diagnoses breast canceri.e. a passage of 65,700 to 75,400 cases per year, as well as a increase of almost 27% in the number of annual deaths caused by breast cancer, i.e. a passage of 14,700 to 20,100 cases per year.« Breast cancer affects increasingly younger women, without family history or traditional risk factors dont the tobacco, alcohol, overweight and sedentary lifestyle); they are the ones most affected by the upward forecast for 2050» specifies André Cicolella, president of the RES during the “Breast Cancer 2050” conference supported by Paris City Hall.
According to scientific evidence, genetic predisposition in breast cancer is a risk factor with low to moderate incidence, and known risk factors such as family history, age, gender, ethnicity and hormones) would not explain only about three cases out of ten. The remaining 70% of cases could and therefore very probably have an origin linked to the environment.
In his presentation, Professor Patrick Fénichel from Nice University Hospital specifies that in 9 cases out of 10women affected by breast cancer do not have no pre-existing genetic mutationsbut epigenetic modifications impacting the expression of certain genes. These are specific changes in the genome that are induced in part by environmental factors.
To know! Epigenetic modifications are materialized by biochemical marks present on DNA and the best characterized is DNA methylation. Reversible, they do not cause modification of the DNA sequence but induce changes in gene expression. They are induced by the environment in the broad sense.
Endocrine disruptors : premiers of the number of cases of cancer of the be ?
In 2017, a scientific inventory reviewing all epidemiological studies published between 2009 and 2017 was carried out by three American researchers highlighted. A link between the exposure of women to environmental substances (air, water and soil) and the increase in the rate of breast cancer has thus been clearly established.
To know! An epidemiological study is the study of the relationships between a disease and various factors (lifestyle, individual characteristics, exposure to a toxic product, etc.) which can have an influence on the frequency or development of this disease.
THE prolonged exposure to the substances in questionfrom embryonic development through early adulthood, reshape the program of genetic, epigenetic, and physiological processes in the developing breast glandular system, resulting in a increased risk to develop breast cancer.
For researchers: “Increasing evidence from epidemiological studies, as well as a better understanding of the mechanisms linking toxic substances to the development of breast cancer, reinforce the conclusion that exposures to these substances – many of which are found in common, everyday products and by-products – may lead to an increased risk of developing breast cancer ».
920 toxic substances have been identified to date. They cover in particular the endocrine disruptors, consumer products, industrial pollutantsthe air pollution or even pesticides.
To know! Endocrine disruptors are substances that act on endocrine function. They directly or indirectly disrupt breast development and can cause harmful long-term consequences. These include compounds such as polychlorinated biphenyls, bisphenol A, dioxins, certain pesticides, perfluorinated and polybrominated compounds and phytoestrogens.
Professor Ana Soto, who worked on the link between exposure to bisphenol A and the occurrence of breast cancer at Tufts University in Boston, spoke at the conference on October 22 last :
« It is high time to realize that we have enough evidence to regulate exposure to endocrine disruptors in order to stop the breast cancer epidemic. »
As a reminder, Public Health France classifies endocrine disruptors in the category “sufficient level of proof» for the link with breast cancer.
in question in the occurrence of cancer be you?
In terms of diet, the third report from the World Cancer Research Fund dating from 2018 shows a link between diet and the occurrence of breast cancer after menopause.
The NutriNet-Santé cohort made it possible to highlight correlations between an increased risk of breast cancer and the presence of sweeteners and emulsifiers. However, additional studies are still needed to demonstrate a causal link. The project “Additives” developed by the NACRE Network (Nutrition, Physical Activity, Cancer Research) is working on these questions.
Conversely, factors reducing the risk of being overweight such as a diet rich in fiber also appear to indirectly reduce the risk of breast cancer, .
Other harmful substances found in food: pesticides. In a study carried out in 2021 as part of the Nutrinet program, French researchers were interested in the role of dietary exposure to pesticides in the occurrence of breast cancer after menopause. Their conclusions after follow-up more than 13,000 women over 4 years? Women with low exposure to several synthetic pesticides have a lower risk of developing breast cancer. On the other hand, this risk is increased in the group of women significantly exposed to four active pesticide substances, namely chlorpyrifos, imazalil, malathion and thiabendazole.
According to the Circ, in France, 40% of new cases of cancer in adults, linked to lifestyle and the environment, would be avoidable. Next step for the scientific community and the RES? Continue to inform the public and authorities to integrate this public health data into preventive policies.
Sources
– Pink October 2050: acting on the environmental causes of breast cancer. www.lequotidiendumedecin.fr. Accessed November 6, 2024.
– Environmental risk factors involved in breast cancer. presse.inserm.fr. Accessed November 6, 2024.
– A look back at the “Breast Cancer 2050” conference on October 22, 2024 at the Climate Academy. www.reseau-environnement-sante.fr. Accessed November 6, 2024.
