Incidence of Hypercalcemia and Vertebral Fractures Following Denosumab Withdrawal in Lung Cancer Patients: A
Marta Villanova1, Sharon H Chou1, Le Min1
1Division of Endocrinology, Diabetes and Hypertension, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
Background:
Bone-target agents (BTAs), including denosumab (DMAb), are one of the bone metastasis treatments that should continue indefinitely. However, BTAs may be interrupted in some cases. In osteoporosis, DMAb withdrawal causes a rebound effect characterized by an increased bone turnover with spine fractures and hypercalcemia; evidence of the DMAb withdrawal effect in oncology is lacking.
Methods:
This study aimed to identify the DMAb withdrawal effect amongst lung cancer patients treated with DMAb for bone metastases between January 2020 and December 2021. Patients who discontinued DMAb were included. Encounter notes, radiological and laboratory findings were comprehensively reviewed.
Results:
Thirty patients were included with a median follow-up of 21 months (interquartile range [IQR], 10-30) after DMAb discontinuation. Bisphosphonates were administered before starting DMAb in 7 patients (23.3%) and after DMAb withdrawal in 4 cases (13.3%). Three cases of DMAb withdrawal-related hypercalcemia and 3 cases of spine fractures following DMAb cessation were identified in 5 patients (16.7%), all of them were females and the median age was 65 years old (IQR, 65-70). No statistical difference in DMAb duration or number of injections was found in patients developing DMAb withdrawal-related spine fractures or hypercalcemia compared with others (binary logistic regression, p=0.688 and p=0.938, respectively).
Conclusions:
Patients with bony-metastatic lung cancer, especially post-menopausal women, are at risk of fractures and calcium abnormalities after DMAb discontinuation, suggesting that DMAb withdrawal effect may also be present in the oncological setting. A close follow-up and careful monitoring during and after discontinuation of DMAb is necessary.
Related Concept Videos
01:29Bone Disorders
Bone deposition is also affected by the levels of sex hormones like estrogen and testosterone that promote osteoblast activity and bone matrix synthesis. When the level of these hormones decreases due to aging, it causes a reduction in bone deposition. As a result, bone resorption by osteoclasts...
01:40Bone Remodeling
01:21Skeleton and Calcium Homeostasis
01:31Osteoclasts in Bone Remodeling
01:25Role of Vitamins in Maintaining Bone Health
Vitamin A
Vitamin A is involved in the process of bone remodeling. Retinoic acid, the active metabolite of Vitamin A, has nuclear receptors in osteoblasts and osteoclasts, which are involved in bone remodeling.
Vitamin B12
Vitamin B12 acts as a cofactor during the formation of osteoblast-related proteins, such as osteocalcin. Vitamin B12 plays a role...