Findings from an analysis of the Women’s Health Initiative showed that women
taking oral bisphosphonates for osteoporosis were less likely to develop
invasive breast cancer.
A total of 2,216 of 151,592 postmenopausal women enrolled in the initiative were
taking either alendronate (89.7%) or etidronate (10.1%) at their entry into the
program.
Rowan Chlebowski, MD, PhD, a medical oncologist at the Los Angeles Biomedical
Research Institute at Harbor-University of California, said that researchers
found a mean 32% fewer breast cancers among women using bisphosphonates compared
to women who did not.
Chlebowski presented the findings during the 32nd Annual CTRC-AACR San Antonio
Breast Cancer Symposium.
The rate of invasive breast cancer was 4.38 per 1,000 person-years of follow-up
for non-bisphosphate users compared to 3.29 per 1,000 person-years for
bisphosphonate users.
“Oral bisphosphonate use may directly inhibit breast cancer incidents,”
Chlebowski said. “There are ongoing randomized trials in an adjuvant setting
looking at contralateral breast cancer and may, in a year or so, be able to
provide confirmation for this observational cohort finding.”
Using the hip fracture risk score to control for bone mineral density between
bisphosphonate users and non-users, the researchers observed 30% fewer estrogen
receptor-positive cancers and 34% fewer entry receptor-negative cancers in
bisphosphonate users.
Reference: Chlebowski R. Oral bisphosphonate and breast cancer: Prospective
results from the Women's Health Initiative. Paper #21 Presented at: 32nd Annual
CTCR-AACR San Antonio Breast Cancer Symposium; Dec. 9-11, 2009. San Antonio,
Texas.
Source : www.orthosupersite.com
