For Professor Patrick Fenichel, Head of Endocrinology at the University Hospital of Nice, certain chemicals are involved in the increase of breast, prostate and testis. These endocrine disruptors disturb our fragile hormonal balance.
Health Magazine: Is there a link between exposure to endocrine disruptors and the current increase in certain cancers?
Prof. Patrick Fenichel: "For now, there is no formal proof. But a number of arguments suggest that exposure to certain endocrine disruptors in a particularly sensitive period of development of breast, prostate and testicle - the fetal period - could explain the increased incidence of these three cancers worldwide. "
What specifically breast cancer?
"This is the most common cancer in women regardless of age. One in nine women will develop one day breast cancer. The incidence of cancer is increasing worldwide.
There are some experimental evidence in rodents that show whether the fetus in the womb at very low doses of some endocrine disruptors, such as bisphenol A and certain organochlorine pesticides, he will develop in adulthood much more easily a cancer of the mammary gland.
- Girls who were exposed to diethylstilbestrol in the womb between the years 1950 and 1970, now have 40 or 50 years. A cohort of women was followed by the USA. It was reported recently that these women between 40 and 50 years were twice as breast cancer than non-exposed women, and beyond 50 years three times. The distilbene is very close to a chemically bisphenol A. It is a potent estrogen.
These elements are associated evoke the hypothesis that exposure to these endocrine disruptors, particularly in a sensitive period of development of the mammary gland during the fetal development, may induce changes called "epigenetic" in of genes that could be expressed twenty or forty years later, in adulthood to promote the onset of breast cancer. "
What arguments do you have for prostate cancer?
"This is the most common cancer in men after age 50. It is increasing, especially in young subjects. Thus the question of the role of the environment.
Exposing rats or pregnant mice at very low doses of endocrine disruptors, one could induce in the progeny greater frequency of prostate cancer in adulthood.
In the Caribbean, there is a statistically significant relationship between blood levels of chlordecone in humans, an organochlorine pesticide used up there ten years, and the occurrence of prostate cancer. The higher the blood levels of chlordecone, the higher the cancer was aggressive. Chlordecone will persist in the environment for 50 years.
DDT, a pesticide banned in France yet for 40 years, persists in the cord blood of newborns. Between 2003 and 2005, we did a test at Nice University Hospital: 80% of cord bloods included high levels of DDE, the most persistent derivative of DDT. This means that we are all exposed to persistent organochlorine pesticides in groundwater, although they have been banned, either here or in the Caribbean. "
We are seeing an increase in cases of testicular cancer. A consequence of endocrine disruptors?
"This is the first cause of cancer in young men between 15 and 35 years. Throughout the world, regardless of the place of the world, this cancer increases by 2% annually for thirty years.
The increase in testicular cancer occurs concomitantly with the decline in male fertility and the increase in birth defects in boys: cryptorchidism and hypospadias. It is known that these defects are increasing frequency and are associated with an increased risk of testicular cancer.
The defects can be easily induced in rodents by exposing the mother to low doses of endocrine disruptors such as phthalates, bisphenol A or métoxichlore.
- Research was conducted in my laboratory Inserm in Nice. We have taken the human testicular cancer cells. We have shown that estrogen, particularly bisphenol A at very low doses, could stimulate their proliferation. "
To learn more, find our special hormones in the August issue of Health Magazine, on newsstands today.