Chemicals in shampoos may increase risk of breast cancer

Estrogen-mimicking chemicals called parabens, which are commonly found in an array of personal care products like shampoos, may be more dangerous than previously thought, according to a new study. The findings, published online October 27 in Environmental Health Perspectives, could have implications for the development of breast cancer and other diseases that are influenced by estrogens. The study also raises questions about current safety testing methods that may not predict the true potency of parabens and their effects on human health.

Parabens are a class of preservatives widely-used in consumer products like shampoos, cosmetics, body lotions, and sunscreens. The chemicals are considered estrogenic because they activate the same estrogen receptor as the natural hormone estradiol. Studies have linked exposure to estradiol and related estrogens with an increased risk of breast cancer, as well as reproductive problems. As a result, the use of parabens in consumer products increasingly has become a public health concern.

How much parabens might contribute to breast cancer risk is unclear. “Although parabens are known to mimic the growth effects of estrogens on breast cancer cells, some consider their effect too weak to cause harm,” says lead investigator Dale Leitman, a gynecologist and molecular biologist at University California, Berkeley. “But this might not be true when parabens are combined with other agents that regulate cell growth.”

However, existing chemical safety tests, which measure the effects of chemicals on human cells, look only at parabens in isolation and fail to take into account that parabens could interact with other types of signaling molecules in the cells to increase breast cancer risk. “Scientists and regulators are using potency estimates from these kinds of tests and are assuming they are relevant to what goes on in real life. But if you don’t design the right test, you can be off by a lot,” says co-author Ruthann Rudel, a toxicologist at Silent Spring Institute.

To better reflect what goes on in real life, the researchers looked at breast cancer cells expressing two types of receptors: estrogen receptors and HER2. Approximately 25 percent of breast cancers produce an abundance of HER2, or human epidermal growth factor receptor 2. HER2-positive tumors tend to grow and spread more aggressively than other types of breast cancer.

The researchers activated the HER2 receptors in breast cancer cells with a growth factor called heregulin that is naturally made in breast cells, while exposing the cells to parabens. Not only did the parabens trigger the estrogen receptors by turning on genes that caused the cells to proliferate, the effect was significant: The parabens in the HER2-activated cells were able to stimulate breast cancer cell growth at concentrations 100 times lower than in cells that were deprived of heregulin.

The study demonstrates that parabens may be more potent at lower doses than previous studies have suggested, which may spur scientists and regulators to rethink the potential impacts of parabens on the development of breast cancer, particularly on HER2 and estrogen receptor positive breast cells.

Since people come into contact with multiple chemicals every day through consumer products, understanding how mixtures of hormone-mimicking chemicals and growth factors interact to promote cell growth might better reflect a person’s potential cancer risk from exposure. In particular, one area of increasing concern is how exposure to multiple chemicals during critical periods of development including puberty and pregnancy increases a person’s susceptibility to breast cancer later in life.

This brings us to the all important question: Do we stop using products like shampoos, sun-screen? 

Few points:

  1. Paraben free products are freely available in the market. Though a bit expensive, they are a good alternate to products which contain these harmful products
  2. Authorities should lay down more stringent guidelines to detect these harmful chemicals in daily use products and determine the minimum tolerable dose of these chemicals in these products
  3. More studies should be carried out to assess the role of parabens in the development of breast cancer 
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Updated Breast Cancer Screening Guidelines

American Cancer Society has recently revised the breast cancer screening guidelines and they were featured in the a recent article in JAMA.

The most significant change has been the age of starting mammographic screening, which has been increased from 40 to 45 years. This change has been made after taking into account the lower incidence rate of breast cancer in this age group. Another factor which led to the delay in initiating screening was the higher number of false positive mammograms observed within this age group.

Recommendations:

  • Women with an average risk for breast cancer should undergo regular screening mammography starting at age 45 years (strong recommendation).
  • Women aged 45 to 54 years should be screened annually (qualified recommendation).
  • Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually (qualified recommendation).
  • Women should have the opportunity to begin annual screening between the ages of 40 and 44 years (qualified recommendation).
  • Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer (qualified recommendation).
  • The ACS does not recommend clinical breast examination for breast cancer screening among average-risk women at any age (qualified recommendation)

These guidelines are quite different from those of the US Preventive Services Task Force (USPSTF) and this is a cause of concern & confusion among patients. The following table highlights the differences between the two guidelines:

Mammography Screening Parameter ACS USPSTF
Starting age (y) 45 50
Screening frequency Annually to age 54 y, then biennially Biennially, beginning at age 50 y
Stopping age (y) For as long as a woman is in good health and has a life expectancy of at least 10 y 75
Total lifetime mammograms if screening continued to age 74 y (n) 20 13
Lifetime risk of dying of breast cancer (%) 1.8-1.9 2.0
Lifetime risk of dying of breast cancer with no screening is 2.7%.

Do these guidelines affect Indian patients?

Well, firstly India has no screening guidelines and only opportunistic screening is practiced by a very small segment of the population. Secondly, there are some studies which say that Indian breast cancer occurs at an earlier age and therefore screening should be initiated early.

These questions be answered if proper trials on this topic are carried out in the country. For the time being, we should lay more stress on creating awareness regarding breast cancer.

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Breast Cancer Awareness Drive

During my training in America, doctors there used to ask me “Why doesn’t India have a Breast Cancer Screening Program?”
Well today, I can proudly say that we are working towards it. You always have to take small steps to fulfill big dreams and that is what we did yesterday by launching the W Pratiksha Hospital Cancer Awareness Drive.
I was happy to see the media supporting the project and giving it the importance it deserves.
We are going to having regular camps in the surrounding villages for the next six months and anyone who would like to volunteer is most welcome.

It was heartening to see one of my treated patients (a breast cancer conqueror) being felicitated during the event. She shared her thoughts with the media as well and told them about the importance of early detection and management.

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BRASCON 2015 – International Breast Surgery Conference

The Pink City (Jaipur) hosted BRASCON 2015, an international breast surgery conference which attracted leading breast surgeons from not only India but also UK. It included a live operative workshop and was attended by more than 400 delegates.

I had the pleasure of presenting an invited talk on “Management of Non Palpable Breast Lesions”, which is a very interesting topic because with the increase in opportunistic screening in our country, we are seeing more and more non palpable lesions and there are special techniques required to manage these lesions.

In my talk, I spoke about my experience regarding wire guided localization (WGT) and ROLL (radio-guided occult lesion localization), both of which are the standard techniques to manage such lesions.

Many British Breast Surgeons were happy to see that we were performing such surgeries in India as well and they appreciated my operative videos.

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