Aromatase inhibitors and fracture prevention - do 2017 guidelines work in real world?

Aromatase inhibitor induced bone loss (AIBL) is a recognised adverse event with resultant increase in fracture risk. We aimed to determine the real-world impact of the 2017 consensus guidelines on AIBL and see if it is effective in fracture prevention.

Over a 7-year study period, 1001 women prescribed AI were split in two groups. First group were offered bone active treatment based on NOS 2008 guidelines whereas the second group followed the 2017 consensus guidelines.

1001 women were included. First group: 361 women had a baseline DEXA with 143 (40%) women who had a normal DEXA, 174 (48%) had osteopenia and 44 (12%) had osteoporosis. Of the women with osteopenia, 44 (25%) women were offered treatment, and 22 (13%) women had a fracture. Second group: 640 women had a baseline DEXA with 216 (33%) women with a normal result, 322(50%) had osteopenia and 107 (17%) had osteoporosis. Of the women with osteopenia, 127 (39%) women were offered treatment, and 8 (2.5%) women had a fracture.

Our study provides real world evidence of the success of 2017 consensus statement in lowering fracture risk. A significant reduction in fractures pre (13%) and post guidelines change (2.5%) was demonstrated (absolute risk reduction of 10.5%) which has implications for healthcare systems worldwide as we have demonstrated this approach can reduce morbidity. Breast cancer is the most common cancer in women with over two million women diagnosed with it annually. Early diagnosis and treatment with hormonal therapies have helped reduce mortality. Aromatase inhibitors (AIs) are the main drugs in this class and have demonstrated improved survival. However, whilst conveying major benefits, AIs reduce oestrogen levels leading to significant bone loss and increasing fracture risk. Several protocols have been recommended to address this concern. We compared the two guidelines published by National Osteoporosis Society UK in 2008 and consensus statement recommended by seven breast cancer and bone health groups in 2017 to see which work better in preventing fractures in women prescribed AIs for breast cancer. Our study shows that the 2017 guidelines are better at preventing fractures in the real world. Hence, we suggest that these should be adopted by specialists treating breast cancer which can help women avoid fractures and improve long term health.