Bone Density Predicts Chances of Breast Cancer

By Amanda Gardner
HealthDay Reporter
Monday, July 28, 2008; 1:00 PM

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MONDAY, July 28 (HealthDay News) -- Calculating a woman's bone mineral density appears to shed light on her risk for breast cancer.

A new study has found that high bone mineral density (BMD) predicts a greater likelihood of developing breast cancer, independent of how high her risk is on the often-used Gail model.

The two measurements together might be used in tandem to better predict breast cancer risk, the researchers said.

The findings, which were expected to be published in the Sept. 1 issue of Cancer, follow closely on the heels of other research linking different aspects of bone health with breast cancer risk. One study presented at the American Society of Clinical Oncology annual meeting in May found that Zometa (zoledronic acid), a drug used to treat osteoporosis, lowered the risk of breast cancer recurrence in premenopausal women.

And another study released this spring found that women with breast cancer who have a vitamin D deficiency at the time of their diagnosis were more likely to have a recurrence or to die from their disease. Vitamin D is also critical to bone health.

The Gail model incorporates information on family history, age and other factors to estimate a woman's risk of breast cancer over five years and over her lifetime. The model does not, however, include data on bone mineral density, which is known to be a risk factor for breast cancer.

This study, led by researchers at the University of Arizona, Tucson, incorporated Gail scores and hip BMD information on almost 10,000 postmenopausal women participating in the Women's Health Initiative.

After an average of almost nine years of follow-up, women with a high Gail score were, overall, 35 percent more likely to develop breast cancer. And for each unit of increase in total hip BMD, a woman's risk rose 25 percent.

There was a particularly high increase in risk for women with the highest BMD and Gail scores.

Women with high bone density often are overweight or obese, a condition which elevates their risk of breast cancer and which may well be the common denominator, said Dr. Jay Brooks, chairman of hematology/oncology at Ochsner Health System in Baton Rouge, La.