Effects of bisphosphonates combined with calcitriol in treating osteoporosis induced by endocrine therapy for breast cancer.

Objective: To evaluate the therapeutic effects of bisphosphonates (specifically zoledronic acid) combined with calcitriol on osteoporosis (OP) induced by endocrine therapy for breast cancer.

Methods: A retrospective analysis was performed on the clinical data from 150 patients with OP induced by endocrine therapy for breast cancer, who were admitted to Yuebei People's Hospital from May 2020 to March 2022. Patients were divided into two groups based on their treatment regimens: 78 patients received oral calcitriol alone (control group), and 72 patients received zoledronic acid combined with calcitriol (study group). Clinical efficacy, pain severity, bone metabolism, bone mineral density (BMD), quality of life, and medication safety were compared between the two groups.

Results: After 12 months of treatment, the total effective rate was significantly higher in the study group compared to the control group (95.83% vs. 79.49%, P < 0.05). Visual analogue scale (VAS) scores decreased progressively at 3, 6, and 12 months in both groups, with the study group showing significantly lower scores (all P < 0.05). Serum alkaline phosphatase (ALP) levels and BMD of the hip, femoral neck, and lumbar spine significantly increased after 12 months in both groups. Scores on the Quality of Life Questionnaire of the European Foundation for Osteoporosis 41 (QUALEFFO-41) decreased significantly in both groups, with greater improvements seen in the study group (P < 0.05). Compared to the control group, the study group showed increased serum calcium and decreased serum phosphorus after 12 months (both P < 0.05). Fracture Risk Assessment Tool (FRAX) scores decreased at 12 and 24 months in both groups, with lower scores in the study group (both P < 0.05). No adverse events were observed in either group during the treatment period.

Conclusion: The combination of bisphosphonates (zoledronic acid) and calcitriol is effective in treating OP induced by endocrine therapy for breast cancer. This combination therapy can regulate bone metabolism, enhance BMD, improve quality of life, and reduce fracture risk, demonstrating a favorable safety profile.