Study links chemical exposure to breast cancer

LONDON Thu Apr 1, 2010 3:02am EDT

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LONDON (Reuters) - Exposure to certain chemicals and pollutants before a woman reaches her mid-30s could treble her risk of developing breast cancer after the menopause, Canadian scientists said on Thursday.

In a study in Occupational and Environmental Medicine, a British Medical Journal title, the researchers found that women exposed to synthetic fibers and petrol products during the course of their work appeared to be most at risk.

"Occupational exposure to acrylic and nylon fibers, and to polycyclic aromatic hydrocarbons may increase the risk of developing postmenopausal breast cancer," they wrote.

But some experts commenting on the study expressed caution, saying such links can crop up by chance.

"In a study of this sort positive associations often occur simply by chance," said David Coggon, a professor of occupational and environmental medicine at Britain's Southampton University. "They carry little weight in the absence of stronger supportive evidence from other research."

The Canadian scientists conceded their findings could be due to chance, but also said they were consistent with the theory that breast tissue is more sensitive to harmful chemicals if the exposure occurs when breast cells are still active -- in other words, before a woman reaches her 40s.

The researchers, led by France Labreche, of the Occupational Health Research Institute in Montreal, Canada, based their findings on more than 1,100 women, 556 of whom were diagnosed with breast cancer in 1996 and 1997 when they were aged between 50 and 75 and had gone through the menopause.

A team of chemists and industrial hygienists investigated the women's levels of exposure to around 300 different substances during their employment history.

After taking account of the usual factors associated with an increased risk of breast cancer, the analysis indicated a link between occupational exposure to several of these substances, Labreche's team wrote.

Compared with the comparison group, the risk peaked for exposures before the age of 36, and increased with each additional decade of exposure before this age, they found.

This meant women who were exposed to acrylic fibers appeared to run a seven-fold risk of breast cancer, while those exposed to nylon fibers almost doubled their risk.

The scientists said more detailed studies focusing on certain chemicals were now needed to try to establish what role chemical exposure plays in the development of breast cancer.

(Reporting by Kate Kelland, editing by Elizabeth Fullerton)

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Comments (3)
Thermoguy wrote:
I applaud the study but they need to give objective medical professionals funding to expand on toxicity studies.

The Environmental Group did a study on umbilical cord blood to see if the umbilical cord protected the fetus from toxins. They found the toxicity ratio was 100% and the fetus was polluted with cancer causing chemicals before their first breath.

Scroll down the link provided and click on the picture of the fetus to link to the study on polluted newborns.

The study was done on US babies and none of the babies worked in an industrial environment, mom passed them to the fetus.

Apr 01, 2010 11:05am EDT  --  Report as abuse
1822sligo wrote:
One study, and we should be concerned about chemical and polutants causing cancer? There have been over two dozen studies that show the connection between abortion and breast cancer, and no one in the media seems concerned about it. Planned Parenthood is aware of these studies, but I doubt they tell abortion clients this information. They probably wouldn’t make the ‘choice’ that Planned Parenthood wants them to make.

Apr 01, 2010 8:06pm EDT  --  Report as abuse
eagreenhalgh wrote:
20 yrs ago I sent material to Pres. Pritchard of U of T (Princess Margaret Cancer Center) explaining Cell Death Signal Gene and the relationship of viruses to genes and hormones having published in this field and peer review by M.D.Anderson Cancer Center as explained on He asked the Dean of Medicine to contact me. Even after I sent courier letters to him he still refused.What people fail to see is the intricate relationship of hormones and chemicals and how they trigger events out of sequence. It is too bad the Dean never helped my research, who knows how many women could have been spared unnecessary suffering and death.

Apr 02, 2010 1:33pm EDT  --  Report as abuse
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