Аннотация:Background: Our purpose was to evaluate bone remodeling markers in assessing the efficiency of osteoporosis therapy in hormone-dependent breast cancer (BC).
Methods: The study included 102 patients: 60.05.0 years, in menopause for 5 years, luminal BC after mastectomy, receiving adjuvant hormonal therapy with aromatase inhibitors and osteoporosis therapy with denosumab (120 mg subcutaneously) or zoledronic acid (4 mg intravenously) every 6 months. The groups were: 1A (n1⁄424) with luminal A and 1B (n1⁄428) with luminal B subtypes receiving denosumab; 2A (n1⁄426) with luminal A and 2B (n1⁄424) with luminal B subtypes receiving zoledronic acid. The bone tissue status was assessed by bone scintigraphy and osteodensi- tometry. P1NP, b-Cross laps, and osteocalcin were studied before and after 6, 12, 18, and 24 months of osteoporosis therapy.
Results: Before the treatment, osteoporosis was found in group 1A - 15 patients, 1B - 13, 2A e 16, 2B e 17. An increase in the bone mineral density in comparison with the initial values was observed in groups 1A and 1B during treatment, unlike groups 2A and 2B. Initial levels of b-Cross laps in all patients were 1.0200.009 ng/ml (vs. normal levels 1.009 ng/ml); in 24 months, their decrease was noted, more pro- nounced in groups 1B (0.8820.024 ng/ml, p<0.01) and 2B (0.8160.037, p<0.001), indicating reduced intensity of pathological bone resorption. Initial P1NP levels were within the reference range in all patients (16.27-73.87 mcg/l). In 24 months, P1NP increased in groups 1B and 2B, indicating the activation of osteosynthesis processes. Initial osteocalcin levels were increased (vs. the norm - 46 ng/ml) in all patients, with the maximum values in groups 1A (62.366.30 ng/ml) and 2A (61.656.10 ng/ml), which indicated bone metabolism suppression. The values decreased during the treatment, especially in groups 1A (40.934.30 ng/ml) and 1B (45.094.4 ng/ml), compared to initial levels (p<0.05). Patients in groups 2A and 2B did not show sta- tistically significant changes in osteocalcin levels.
Conclusions: P1NP, b-Cross laps, and osteocalcin values are promising in monitoring the efficiency of osteoporosis therapy in BC patients. Denosumab is more effective in preventing pathological bone resorption.