Abstract 62P
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: 60.0±5.0 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 (n=24) with luminal A and 1B (n=28) with luminal B subtypes receiving denosumab; 2A (n=26) with luminal A and 2B (n=24) with luminal B subtypes receiving zoledronic acid. The bone tissue status was assessed by bone scintigraphy and osteodensitometry. P1NP, β-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 – 16, 2B – 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 β-Cross laps in all patients were 1.020±0.009 ng/ml (vs. normal levels 1.009 ng/ml); in 24 months, their decrease was noted, more pronounced in groups 1B (0.882±0.024 ng/ml, p<0.01) and 2B (0.816±0.037, 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 (62.36±6.30 ng/ml) and 2A (61.65±6.10 ng/ml), which indicated bone metabolism suppression. The values decreased during the treatment, especially in groups 1A (40.93±4.30 ng/ml) and 1B (45.09±4.4 ng/ml), compared to initial levels (p<0.05). Patients in groups 2A and 2B did not show statistically significant changes in osteocalcin levels.
Conclusions
P1NP, β-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.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.