Breast Cancer Risk Linked to Bone Density
Calculating a woman's bone mineral density appears to
shed light on her risk for breast cancer, says a report in the journal
Cancer.
The study found that high bone mineral density predicts
a greater likelihood of developing breast cancer - independent of how high a
woman’s risk is on the often-used Gail model.
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.
The two measurements together might be used in tandem
to better predict breast cancer risk, the researchers say.
The findings 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 meeting found that Zometa® (zoledronic
acid), a medication 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 new study incorporates Gail scores and hip bone
mineral density 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 bone
mineral density, a woman's risk rose 25 percent.
There was a particularly high increase in risk for
women with the highest bone mineral density 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, says Dr. Jay Brooks, at Ochsner Health
System in Baton Rouge, Louisiana.
"This is more information that shows a link in my
opinion, between increasing weight, obesity, and the development of breast
cancer," he adds.
But the picture for women remains a complicated one,
another expert says.
"Even with these additional findings, however, it's
still not clear what the precise relationships are between estrogen, bone
density, and breast cancer," says Dr. Mary Daly, at the Fox Chase Cancer
Center in Philadelphia.
Always consult your physician for more information.