Although hip fractures are rare in people younger than 70 years, they appear to strike at a much younger age in women who have been treated for breast cancer.
The study generating this finding combined clinical assessment of six female breast cancer survivors (median age: 53.5 years) and a systematic review of case reports, FDA Adverse Event Reporting System (AERS) data, and the medical literature from January 1998 to December 2008. The six participants all had early-stage breast cancer. Treatments included lumpectomy, radiation therapy, and chemotherapy 1 to 4 years prior to hip fracture.
Five of the women had been administered the aromatase inhibitor (AI) anastrozole (Arimidex). Recent research has linked AIs with hip fractures, and the AERS and other databases revealed aromatase inhibitors to be the most common drug class associated with these injuries. The AERS data also showed that 77 of 228 fractures (29%) associated with breast cancer therapy were hip or femur fractures. There were 78 fractures in middle-aged women younger than 64 years.
The women underwent bone mineral density (BMD) testing from January 2005 to December 2008, and the researchers evaluated data on their functional status both before the fracture and 1 year post-fracture. The patients were all perimenopausal when their fractures occurred.
At the 1-year mark, the investigators noted functional decline. The women had difficulty doing heavy housekeeping, climbing stairs, and shopping.
Only one women had osteoporosis; the remaining five had osteopenia—a finding that surprised Beatrice J. Edwards, MD, the lead author of the study. (Dr. Edwards also is the director of the bone health and osteoporosis program at Northwestern University Feinberg School of Medicine, Chicago, Illinois, and a member of Northwestern’s Robert H. Lurie Comprehensive Cancer Center.) In a statement describing her team’s results, which were published in Clinical Care Research (2011;17:560-568), Dr. Edwards explained that the finding of osteopenia rather than osteoporosis suggests that BMD tests may not pick up the rapid change in bone architecture caused by chemotherapy, early menopause, and adjuvant therapy.
“Although the majority of women with breast cancer can expect to be fully cured from the disease, the prevention of cancer treatment-induced bone loss is important to consider in cancer survival,” Dr. Edwards commented in the statement.
The research team concluded that cancer treatment-induced bone loss results in hip fractures among mid-life women with breast cancer. “Hip fractures occur at younger ages and higher BMD than expected for patients in this age group without breast cancer,” they wrote.
Acknowledging that more research needs to be done before treatment guidelines are changed, Dr. Edwards called for greater awareness of the adverse effects of certain drugs used for breast cancer. She recommended performing bone-density screenings on women with breast cancer before initiating chemotherapy. High-risk patients could then be flagged, given preventive treatment for bone loss, and be monitored for premature hip fractures. Such early intervention might reduce pain, suffering, and hospital stays for the patient, as well as the associated health costs.