Breast cancer risk may rise with high hormone levels

Elevated levels of hormones increase breast cancer risk in postmenopausal women, and as the number of different elevated hormones rises, so does the risk, a new study has found

Researchers from Brigham and Women's Hospital and Harvard Medical School in Boston examined levels of eight different sex and growth hormones in blood samples collected from nurses up to nine years before their health information was recorded the risk of breast cancer increased 16 percent with each elevated hormone level, according to the study published online Oct. 21 in the journal Breast Cancer Research.

The investigators found that the highest levels of circulating estrogens (estrone and estrogen), prolactin, and androgens (testosterone, androstenedione, DHEA, or DHEA-sulfate) were each associated with between a 50 and 200 percent increased risk of developing breast cancer.

A woman with elevated levels of one hormone had a 10 percent increased risk, while the risk was doubled for those with elevated levels of five or six hormones, and tripled for those with elevated levels of seven or eight hormones, the study authors explained in a journal news release.

And for women with estrogen receptor-positive (ER-positive) breast cancer, all of these risks were slightly higher, the researchers pointed out.

"Elevated estrogens had the biggest effect on risk, especially for ER-positive cancer. However, androgens and prolactin also contribute to increasing risk of breast cancer. These hormones are known to stimulate the growth of breast cancer cells in the lab and, while androgens can be converted to estrogen in the body, these hormones have also been found to stimulate cancer cell growth in the absence of ER," Shelley Tworoger, of Brigham and Women's Hospital, explained in the news release.

Alternative Health News

Read More

Nervous System Imbalance May Cause Fatigue in Breast Cancer Survivors

The persistent fatigue and exhaustion plaguing some breast cancer survivors after successful treatment stems from a tug of war between the "fight-or-flight" and "resting" parts of the autonomic nervous system, with the former working overtime and the other unable to rein it in, a new study suggests.

Researchers from Ohio State University split 109 women who had completed breast cancer treatment up to two years earlier into two groups -- those who did and didn't report long-term fatigue -- and tested their blood for a baseline level of norepinephrine, a stress hormone. Participants were then asked to give a five-minute speech and do a series of verbal math problems, both tasks aimed at increasing their stress levels.

As expected, further blood tests showed that levels of norepinephrine -- associated with the "fight-or-flight" sympathetic nervous system -- rose in both groups after the stressful experience, researchers said. However, breast cancer survivors who experienced persistent fatigue had higher levels than those who weren't chronically tired.

The study, released online in advance of publication in an upcoming print issue of the journal Psychoneuroendocrinology, was partially funded by the U.S. National Institutes of Health and the American Cancer Society.

The findings are the most recent from a 30-year-long study about the effects of stress on the human body. The researchers used earlier data from a larger ongoing study looking at whether yoga can ward off continuing fatigue in breast cancer patients.

Read More