Breast cancer increases: Are hormone disrupting chemicals the reason?

Researchers may have been overlooking crucial factors in their hunt for an answer to why breast cancer cases are increasing - especially the impacts of hormone disrupting chemicals (known as EDCs), a new paper concludes today.

The paper,  Environmental contaminants and breast cancer: the growing concerns about endocrine disrupting chemicals,  has been written by Andreas Kortenkamp Head of Centre of Toxicology from the School of Pharmacy at London University - an expert on EDC cocktail effects - after WWF sought independent scientific advice from him on the subject.

The paper states that less than half of the new breast cancer cases diagnosed can be explained by lifestyle factors and genetics. It argues that the answer to these other increases may lie in hormone disrupting chemicals, with two key factors playing a significant role - first, the “cocktail effect” which is seen when there is simultaneous exposure to several oestrogen mimicking chemicals and secondly, exposure to the chemicals during critical periods, when baby girls are in the womb or during puberty.

  But researchers and governments are not focusing enough on either exposure to chemicals at these key times - when the breast tissue is developing - or the impacts of chemical “cocktails.”

  Dr Kortenkamp explains: “To prove or dismiss a link with breast cancer, exposure to chemicals must be recorded many years before the cancer becomes manifest. Measuring chemicals at a time when the disease is diagnosed will miss important features and will provide a warped picture.”

The paper highlights the need for strong legislation to control chemicals that have hormone disrupting properties but which are used in everyday products. These chemicals appear in a wide range of products from baby bottles and other plastics to cosmetics.

Dr Kortenkamp added: “It is well known that women with higher lifetime exposure to oestrogen are at a greater risk of breast cancer, so it is highly plausible that chemicals which mimic oestrogen can add to this risk.

 “A recent study among Spanish women demonstrated that breast cancer risk was associated with the body burden of all estrogenic chemicals, excluding the natural hormones. This is the first evidence that chemicals in our environment, with oestrogenic properties that are ‘accidental’, and not just natural hormones or pharmaceutical oestrogens may contribute to the development of breast cancer.”

The EU is currently finalizing a new piece of legislation called REACH, which is designed to protect people and the environment from harmful man-made chemicals. WWF, has been pushing for REACH to be effective and robust, but the chemicals industry has been lobbying hard to make the legislation toothless.

Paul King, Director of Campaigns for WWF-UK said: “The case for a strong REACH has never been clearer. It would be an outrage for European governments to gamble with the health of their citizens by allowing endocrine disrupting chemicals to continue to be used even where safer alternatives available. Two weeks ago David Cameron announced that the Conservatives would join the Liberal Democrats in backing the substitution of hazardous chemicals, now is the time for the UK Government to do the same.”

“Numerous other health concerns including testicular cancer, genital malformation and earlier puberty have also been associated with these chemicals.”

The paper is supported by the National Federation of Women’s Institutes and No More Breast Cancer Campaign.

  (17/10/06)