A study suggesting that breast cancer patients on aromatase-inhibitors (AIs) are at higher risk of fractures has prompted several international medical associations to revise guidelines aimed at preventing bone loss in these patients.

The organizations include the International Osteoporosis Foundation, Cancer and Bone Society, International Expert Group for AIBL, European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, European Calcified Tissue Society, International Menopause Society, and the International Society for Geriatric Oncology (SIOG).

Their recommendations can be found in the study “Management of Aromatase Inhibitor-Associated Bone Loss (AIBL) in postmenopausal women with hormone sensitive breast cancer.” It was published online ahead of the print edition of the Journal of Bone Oncology.

Women receiving AIs as an adjuvant breast cancer therapy have two to four times the bone loss of women in menopause, a condition that itself increases the risk of fracture, the study said. An adjuvant therapy is one aimed at increasing the effect of another treatment.

“While clinical trials have shown an approximately 10% increase in absolute fracture risk for women on AI therapy, other real-world studies indicate that the fracture risk may be significantly higher,” René Rizzoli, chairman of the International Osteoporosis Foundation’s Bone and Cancer Working Group, said in a press release. “Additionally, breast cancer patients hospitalized for a bone fracture showed a higher risk of death compared to breast cancer patients without a bone fracture. These are compelling reasons to ensure that all women on AI therapy for breast cancer receive early assessment and treatment.”

The revised guidelines the organizations put together include such strategies for preventing bone loss as:

• Assessing the condition of patients starting AI treatment, and giving them advice on exercising and using calcium and vitamin D supplements.
• Recommending bone-retention therapy for some patients receiving AIs.
• Using patients’ bone mineral density loss during their first year to management their bone situation, along with guidelines on postmenopausal osteoporosis.
• Giving patients six months of denosumab or a year of zoledronate, depending on one of two treatment priorities. Denosumab should be used if the priority is preventing a recurrence of breast cancer. Zoledronate should be used if the priority is reducing the risk of fracture.
• Recommending adjuvant bisphosphonates for postmenopausal women at risk of their breast cancer recurring.
• Checking whether patients are complying with bone-related treatment recommendations, and measuring bone density 12 to 24 months after they finish treatment.

Chemotherapy, radiotherapy,  a family history of hip fractures, and low weight also can raise the risk of fractures, the study’s authors noted. They called for additional research to examine the role these factors play in breast cancer patients experiencing fractures.