Vertebral fractures after denosumab discontinuation in breast cancer
survivors---a single institution experience
Abstract
Aim: To evaluate clinical vertebral fractures after denosumab
discontinuation in patients with breast cancer. Methods: To evaluate the
occurrence of clinical vertebral fractures after denosumab
discontinuation, we conducted a retrospective chart review to identify
patients with a history of breast cancer who were treated with denosumab
between June 1, 2010 and July 18, 2018 at Memorial Sloan Kettering
Cancer Center. We identified 335 postmenopausal female patients and one
male patient with nonmetastatic breast cancer who received at least two
doses of denosumab (60 mg) and had received their final denosumab
injection at least 6.5 months earlier. Results: The median age of
patients was 62 years (54–69). Patients received between two and 13
denosumab doses before drug discontinuation. The majority of patients
(310; 92.3%) were also treated with aromatase inhibitors. Of the 194
patients with baseline bone-density data, 50 (25.8%) had normal bone
density, 97 (50.0%) had osteopenia, and 47 (24.2%) had osteoporosis.
The median follow-up duration from the last denosumab dose was 18.5
months (12.5–23.5). We identified one case of spontaneous vertebral
fractures after denosumab stoppage. We found no cases of osteonecrosis
of the jaw or atypical femur fracture. A majority of patients (88%) had
a gap in denosumab dosing. Conclusions: Patients with breast
cancer—especially those taking aromatase inhibitors—taking denosumab
should be warned of the risks of delaying denosumab. Larger prospective
studies are needed to fully evaluate the risks of stopping or delaying
denosumab