Fwd: Physical activity as a negative modulator of estrogen-induced breast cancer.

---------- Forwarded message ----------
From: HubMed - breast cancer <rssfwd@rssfwd.com>
Date: Wed, Jun 11, 2008 at 11:46 PM
Subject: Physical activity as a negative modulator of estrogen-induced breast cancer.
To: mesothelioma77@gmail.com


[1]Cancer Causes Control. 2008 Jun 10;
Coyle YM

Physical activity is a protective factor for breast cancer. Exposure to estrogen is an important determinant of breast cancer risk and exercise reduces estrogen levels, with the level of evidence being stronger for post-menopausal women. Possible mechanisms for estrogen induced breast cancer include increased breast epithelial cell proliferation, the metabolism of estrogen to genotoxic metabolites, such as DNA-adducts, and the silencing of tumor suppressor genes (TSGs) that have been implicated in breast carcinogenesis by inducing gene promoter hypermethylation, which is potentially reversible. Animal studies suggest that physical activity decreases breast tumor growth by promoting changes in cellular proliferation and apoptosis. Human studies provide some support for exercise producing favorable changes in estrogen metabolism that may lead to reduced breast epithelial cell proliferation. No studies have been performed to determine whether exercise decreases the accumulation of estrogen metabolite DNA-adducts in breast tissue. However, research supports the hypothesis that physical activity reduces promoter hypermethylation of TSGs implicated in breast carcinogenesis by lowering circulating estrogen levels. Thus, further research is necessary to clarify the mechanisms that relate to physical activity as a negative modulator of breast cancer risk to develop meaningful guidelines for the use of physical activity in breast cancer prevention.



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Source: http://www.hubmed.org/display.cgi?uids=18543069
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Fwd: Pattern of metastatic spread in triple-negative breast cancer.

---------- Forwarded message ----------
From: HubMed - breast cancer <rssfwd@rssfwd.com>
Date: Wed, Jun 11, 2008 at 11:46 PM
Subject: Pattern of metastatic spread in triple-negative breast cancer.
To: mesothelioma77@gmail.com


[1]Breast Cancer Res Treat. 2008 Jun 10;
Dent R, Hanna WM, Trudeau M, Rawlinson E, Sun P, Narod SA

Purpose The prognosis of women with triple-negative breast cancers (defined as cancers that are estrogen receptor-negative, progesterone receptor-negative and HER2/neu negative) is poor, compared to women with other subtypes of breast cancer. It is proposed that the underlying difference in recurrence rates may be explained in part by different routes of metastatic spread. Experimental design We studied a cohort of 1608 patients diagnosed with breast cancer, diagnosed between January 1987 and December 1997 at Women's College Hospital in Toronto. Triple-negative breast cancers were defined as those that were estrogen receptor-negative, progesterone receptor-negative and HER2/neu-negative. We compared the incidence rates of metastatic spread to bone and to other (non-bone) organs in women with triple-negative and other forms of breast cancer. Results Of the 1,608 patients, 180 (11.2%) had triple-negative breast cancer. The 1608 women were followed for a median of 9.0 years (range 0.1-19 years). Compared to other patients, those with triple-negative breast cancer had an increased likelihood of distant recurrence over the study period (adjusted hazard ratio (HR) 1.9; 95% CI: 1.5-2.5, P

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Source: http://www.hubmed.org/display.cgi?uids=18543098
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