Shihan Zhou,1 Mingxia Jiang,1 Jiaxuan Liu,1 Mengqi Zhang,1 Mingxiao Li,1 Maiyue He,1 Nilupai Abudureheiyimu,1 Wenna Wang,1 Xiuwen Guan,1 Fei Ma,1 Binghe Xu,2 Qiao Li1 

1Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China; 2Department of Medical Oncology, State Key Laboratory of Mocelular Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China

Correspondence: Binghe Xu, Department of Medical Oncology, State Key Laboratory of Mocelular Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China, Email xubinghebm@163.com Qiao Li, Department of Medical Oncology, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China, Email liqiao@cicams.ac.cn

Purpose: Bone metastasis is a common complication in advanced breast cancer. Bisphosphonates like incadronate disodium have shown potential in reducing bone resorption and skeletal-related events. We therefore performed a retrospective study to evaluate the safety profile of incadronate disodium in breast cancer patients with bone metastases.
Patients and Methods: This retrospective study was conducted involving 84 breast cancer patients with bone metastases who received incadronate disodium treatment between February 2022 and August 2024 in our center. The primary endpoint was the incidence of dental-related issues and acute phase reactions, with an analysis of the associated risk factors. The secondary endpoint was the incidence of other adverse events. Adverse events were recorded during treatment and within 90 days post-treatment.
Results: Dental-related issues were observed in 33.3% of patients and only one (1.2%) developed medication-related osteonecrosis of the jaw. Higher risk was significantly associated with prolonged treatment duration (OR = 4.33, 95% CI:1.21– 15.50), secondary bone metastases (OR = 6.3, 95% CI:1.58– 25.00), and lower hemoglobin levels (OR = 4.16, 95% CI:1.31– 13.2) at multivariate analysis. 26.2% patients occurred acute phase reactions. Higher medication doses (OR = 1.41, 95% CI:1.07– 2.05), multiple metastatic sites (OR = 4.22, 95% CI:1.39– 15.89) and lower hemoglobin levels (OR = 3.27, 95% CI:1.21– 9.22) were significant in univariate analysis, but not in multivariate analysis. Rare adverse effects included renal dysfunction (1.2%) and hypocalcemia (4.76%).
Conclusion: Incadronate disodium demonstrates a favorable safety profile for treating bone metastases in breast cancer patients. Identified risk factors, such as prolonged treatment duration and lower hemoglobin levels, highlight the need for intensified dental health management and personalized treatment strategies.

Keywords: breast cancer, bone metastasis, bisphosphonate, incadronate disodium, adverse effect