Journal Articles
Job exposure to chemicals 'boosts breast cancer risk'
Workplace exposure to synthetic fibres and certain oil byproducts before her mid-30s triples a woman's risk of breast cancer after menopause, a study among Canadian patients said Thursday
France Labreche of the National Institute of Public Health in Montreal led an investigation into the health records of 1,169 women aged 50 to 75.
Just under half had been diagnosed with breast cancer in 1996 and 1997, after having undergone menopause. The other 613 women were diagnosed during the same period with other forms of cancer and acted as a comparison.
A squad of chemists and industrial hygienists probed the extent to which all the women had been exposed to about 300 different substances throughout their working life. After filtering out other known causes of breast cancer, they found a strong link between higher rates of risk and exposure to several common synthetic materials, found in textile factories and other industrial settings.
Compared to the non-breast cancer group, the risk peaked before the age of 36, when still-active cells in breast tissue are thought to be more sensitive to harmful chemicals. Women occupationally exposed to acrylic fibres ran a seven-fold risk of breast cancer, while exposure to nylon fibres nearly doubled the risk.
Among breast cancer patients, those whose tumours responded well to oestrogen treatment, but not progesterone treatment, were more than twice as likely to have breast cancer for every decade they were exposed to so-called monaromatic hydrocarbons — a byproduct of crude oil — and to acrylic or rayon fibres.
Oestrogen and progesterone are both naturally-occurring hormones used in breast cancer treatment.
Exposure before the age of 36 to another class of hydrocarbons found in petroleum products tripled the risk for women whose tumours responded to both types of hormone treatment. The authors concede that the results are not conclusive, but point out that they are consistent with the theory that breast tissue is more susceptible to chemical toxins in women under 40. They also note the rising rate of breast cancer in rich countries, which could also be due to earlier and better diagnosis and increased rates of alcohol consumption.
The study is published in a British journal, Occupational and Environmental Medicine.
Comparative Effectiveness of Medications To Reduce Risk of Primary Breast Cancer in Women
USA Agency for Healthcare Research and Quality (AHRQ) September 2009
Key questions were:
Key Question 1. In adult women without pre-existing breast cancer, what is the
comparative effectiveness of selective estrogen receptor modulators (SERMs) tamoxifen
citrate and raloxifene, and the selective tissue estrogenic activity regulator (STEAR)
tibolone, when used to reduce risk for primary breast cancer on improving short-term and
long-term outcomes including invasive breast cancer, noninvasive breast cancer, including
ductal carcinoma in situ (DCIS), breast cancer mortality, all-cause mortality, and
osteoporotic fractures?
Key Question 2. What is the evidence for harms of tamoxifen citrate, raloxifene, and
tibolone when used to reduce risk for primary breast cancer?
Key Question 3. How do outcomes for tamoxifen citrate, raloxifene, and tibolone when
used for primary prevention of breast cancer vary by heterogeneity in subpopulations?
Key Question 4. What is the evidence that harms or secondary potential benefits listed
above affect treatment choice, concordance, adherence, and persistence to treatment with
tamoxifen citrate, raloxifene, and tibolone when used for primary prevention of breast
cancer?
Key Question 5. What methods, such as clinical risk-assessment models, have been used to
identify women who could benefit from medications to reduce risk of breast cancer?
Canadian Expert Panel on Tobacco Smoke and Breast Cancer Risk (April 2009)
A recent report from the Canadian Expert Panel on Tobacco Smoke and Breast Cancer Risk (2009) explains the relationship between smoking and breast cancer. It is not only direct inhalation of the 20 known mammory carcinogens that presents a direct risk to smokers: smoldering cigarettes and second hand smoke are associated with increased breast cancer in young/non smoking women. Read the facts and protect yourself and those around you.
Environmental and Occupational Causes of Cancer
(A Review of Recent Scientific Literature) September 2005
This paper summarizes recent scientific evidence of
environmental and occupational links to nearly 30 types of
cancer.