The Relationship Between Xenoestrogens and Cancer

Xenoestrogens are bad enough when they’re just messing with our body’s hormones, but research shows that the reality is even worse than that. They are being found to have a relationship with various forms of cancer, and not a good one. The most studied one, at the time of writing, was the relationship between xenoestrogens and breast cancer. Breast cancer alone kills 40,000 women a year in the US. And if that wasn’t bad enough, new research is also linking xenoestrogens to testicular and prostate cancer, and maybe even more. The relationship between xenoestrogens and cancer is a complex one.

HOW DO XENOESTROGENS CAUSE CANCER

A simple diagram of the differences between healthy cells and cancerous ones.
A simple diagram of the differences between healthy cells and cancerous ones.

So how exactly can xenoestrogens contribute to the development of cancer? Estrogen was recently found to be a carcinogen 1, and xenoestrogens mimic the effects of estrogen in the body. Generally speaking, xenoestrogens interact with certain types of cancer in the same way normal estrogen does. Just like our bodies have hormone receptors that respond to the presence of a particular hormone, so too do some cancers contain hormone receptors. And when that receptor is activated, it sends a sort of message that triggers a certain response. What exactly this message is and what it triggers can vary quite a bit depending on the particulars of the situation. So just like estrogen would interact with a cancer 2 so too do xenoestrogens.

Knowing that, how exactly are xenoestrogens any worse than normal estrogen in this regard? Since the normal presence of estrogen already interacts with cancers the same way that a xenoestrogen would, how are xenoestrogens any worse? The exact answer to that is yet unknown, but one of the likely culprits is that the regular presence of xenoestrogens has an equivalent effect as a very high level of estrogen, the likes of which a person is unlikely to experience through natural means. Xenoestrogens make men have higher than usual estrogen levels, and the same goes for women.  This means that just like HRT (Hormone Replacement Therapy) increases the risk of estrogen-related cancers 3, xenoestrogens do too. Another possibility is that some xenoestrogens have a more potent estrogenic effect than actual estrogen. Whatever the case may be, it’s clear that exposure to xenoestrogens increases the risk of estrogen-related cancers 4.

 

XENOESTROGENS AND BREAST CANCER

The pink ribbon is a popular symbol of the struggle against breast cancer.
The pink ribbon is a popular symbol of the struggle against breast cancer.

To start with, let’s take a look at one of the best known and researched cancers – breast cancer. The average American woman today has a 1 in 8 chance of being diagnosed with breast cancer at some point in her life, up from a 1 in 11 chance in the 1970s 5. There are a few possible explanations for this increase, including longer average life expectancy. The increased presence of environmental xenoestrogens is another.

The relationship between estrogen and breast cancer has been confirmed by this point 6, while the fine details continue to be studied. One surprising recent discovery was that HRT (hormone replacement therapy) when used for post-menopausal women to help mitigate the effects of their reduced estrogen levels actually tripled their risk of breast cancer 7. That is a remarkable increase and lends credence to being wary of hormone disruptors (such as xenoestrogens) on the development of cancer.

Xenoestrogens have been found to affect the incidence of breast cancer in a number of recent studies. For example, BPA (a known xenoestrogen) that is found in many plastics and processed foods was found to increase the risk of breast cancer 8. This is especially troubling considering how common BPA is in modern environments.

 

XENOESTROGENS AND TESTICULAR CANCER

Though it may be surprising, a relationship has also been found between estrogen and the development of testicular cancer. For one, the children of mothers exposed to exogenous sources of estrogen (like xenoestrogens or from milk) during pregnancy have a higher chance of developing testicular cancer later in life 9. This same exposure also seems to increase those men’s risk of infertility. Yet another reason that pregnant women should be wary of xenoestrogens.

That’s one thing, but what about grown men being exposed to xenoestrogens? There hasn’t been a whole lot of research done on the possible relationship between estrogen and testicular cancer, but what little there is strongly suggests they are related. We know that estrogen does play an important role in the healthy function of the testicles 10. Unfortunately, it seems that estrogenic influences, like from xenoestrogens, may also be partly responsible for an increase in testicular germ cancer (the most common type of testicular cancer in young men) 11. It was also found that men who frequently work with PVC (a type of plastic) have an increased risk of testicular cancer 12. This is likely due to the phthalates used in PVC, which are known to be xenoestrogens, but this is not confirmed.

 

XENOESTROGENS AND PROSTATE CANCER

Estrogen has also been found to play a role in the development of prostate cancer, which means xenoestrogens do as well. Paradoxically, estrogen may function both as a treatment for prostate cancers, and as a trigger for the development of it. DES (diethylstilbestrol) treatment is used in some cases as a treatment for prostate cancer, with varying levels of success 13. DES is a very strong estrogen.

There are a number of potential mechanisms behind estrogen contributing to the development of prostate cancer. This is an area of active research today. But it is clear that some sort of relationship exists between the two 14 as these comprehensive reviews show 15. And as estrogen has these effects, so too do xenoestrogens. Additionally, a specific xenoestrogen, BPA, has been found to be involved with the development of prostate cancer 16.

 

HOW TO MITIGATE THE EFFECTS OF XENOESTROGENS ON CANCER

The best way to avoid the likely increased risk of cancer from xenoestrogen exposure is to simply avoid being exposed to xenoestrogens. This is much easier said than done in the modern world, however. And not all potential sources of xenoestrogens are equally troublesome. Identify sources of xenoestrogens in your lifestyle, decide which are the biggest threats, and gradually work to reduce or eliminate them.

BPA is probably the best researched xenoestrogen and more than one of the referenced studies mention it in particular as a cancer risk. It also happens to be extremely common in modern environments, two common sources being plastic and processed foods. Minimizing your exposure to BPA is a great start to living healthier, and you can read more about how to do that here.

Xenoestrogens are also found in a number of personal hygiene products, like shampoo, moisturizing lotion, and makeup. You can reduce or eliminate your exposure in this area by switching to alternative products that are free of xenoestrogens like parabens, or making your own hygiene products using simple ingredients.

A few other common sources of xenoestrogens to be aware of are tap water, nonstick pans, and dairy products. It’s nearly impossible to completely eliminate every potential xenoestrogen in your life overnight, so prioritize them based on your individual lifestyle and address them one at a time.

(Header image credit to Destroyer of Furries at Wikimedia)

Notes:

  1. https://www.niehs.nih.gov/news/newsroom/releases/2002/december11/index.cfm
  2. Chen GG1, Zeng Q, Tse GM. Estrogen and its receptors in cancer. Med Res Rev. 2008 Nov;28(6):954-74.
  3. Post-menopausal estrogen therapy. IARC Mongr Eval Carcinog Risks Hum. 1992;72:399–530
  4. Aleksandra Fucic, Marija Gamulin, Zeljko Ferencic, Jelena Katic, Martin Krayer von Krauss, Alena Bartonova and Domenico F Merlo. “Environmental exposure to xenoestrogens and oestrogen related cancers: reproductive system, breast, lung, kidney, pancreas, and brain” Environmental Health201211(Suppl 1):S8 28 June 2012
  5. https://www.cancer.org/content/dam/cancer-org/research/cancer-facts-and-statistics/breast-cancer-facts-and-figures/breast-cancer-facts-and-figures-2013-2014.pdf
  6. Russo J1, Russo IH. “The role of estrogen in the initiation of breast cancer.“ J Steroid Biochem Mol Biol. 2006 Dec;102(1-5):89-96.
  7. Michael E Jones, et al “Menopausal hormone therapy and breast cancer: what is the true size of the increased risk?” British Journal of Cancer (2016) 115, 607–615. doi:10.1038/bjc.2016.231 www.bjcancer.com  28 July 2016
  8. S.V. Fernandez and J. Russo “Estrogen and Xenoestrogens in Breast Cancer” Toxicol Pathol. 2010; 38(1): 110–122. Published online 2009 Nov 21
  9. Depue RH, Pike MC, Henderson BE. “Estrogen exposure during gestation and risk of testicular cancer.” J Natl Cancer Inst. 1983 Dec;71(6):1151-5.
  10. Margaret E.E. Jones, Evan R. Simpson “Oestrogens in male reproduction” Best Practice & Research Clinical Endocrinology & Metabolism Volume 14, Issue 3, September 2000, Pages 505–516
  11. Adil Bouskine, Marielle Nebout, Baharia Mograbi, Françoise Brücker-Davis, Cyril Roger, Patrick Fenichel “Estrogens Promote Human Testicular Germ Cell Cancer through a Membrane-Mediated Activation of Extracellular Regulated Kinase and Protein Kinase A” Endocrinology (2008) 149 (2): 565-573. 26 November 2007
  12. Ohlson CG1, Hardell L. “Testicular cancer and occupational exposures with a focus on xenoestrogens in polyvinyl chloride plastics.” Chemosphere. 2000 May-Jun;40(9-11):1277-82.
  13. Malkowicz SB. The role of diethylstilbestrol in the treatment of prostate cancer. Urology. 2001;58(suppl 1):108–113.
  14. Maarten C Bosland “The Role of Estrogens in Prostate Carcinogenesis: A Rationale for Chemoprevention” Rev Urol. 2005; 7(Suppl 3): S4–S10.
  15. Jason L Nelles, Wen-Yang Hu, and Gail S Prins “Estrogen action and prostate cancer” Expert Rev Endocrinol Metab. 2011 May; 6(3): 437–451.
  16. Wetherill YB1, Fisher NL, Staubach A, Danielsen M, de Vere White RW, Knudsen KE. “Xenoestrogen action in prostate cancer: pleiotropic effects dependent on androgen receptor status.” Cancer Res. 2005 Jan 1;65(1):54-65.

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