Effect of cytotoxic chemotherapy on bone health among breast cancer patients. Does it require intervention?

Treatment affects load to failure and microdamage accumulation in healthy and osteolytic rat vertebrae

Bone turnover and microdamage are impacted by the presence of skeletal metastases which can contribute to increased fracture risk. Treatments for metastatic disease may further impact bone quality. This exploratory study aimed to establish an initial understanding of microdamage accumulation and load to failure in healthy and osteolytic rat vertebrae following focal and systemic cancer treatment (docetaxel (DTX), stereotactic body radiotherapy (SBRT), or zoledronic acid (ZA)). Osteolytic spine metastases were developed in 6-week-old athymic female rats via intracardiac injection of HeLa human cervical cancer cells (day 0). Additional rats served as healthy controls. Rats were either untreated, received SBRT to the T10-L6 vertebrae on day 14 (15 Gy, two fractions), DTX on day 7 or 14, or ZA on day 7. Rats were euthanized on day 21. Tumor burden was assessed with bioluminescence images acquired on day 14 and 21, histology of the excised T11 and L5 vertebrae, and ex-vivo μCT images of the T13-L4. Microstructural parameters (bone volume/total volume, trabecular number, spacing, thickness, and bone mineral density) were measured from L2 vertebrae. Load to failure was measured with axial compressive loading of the L1-L3 motion segments. Microdamage accumulation was labeled in T13 vertebrae with BaSO4 staining and was visualized with high resolution μCT imaging. Microdamage volume fraction was defined as the ratio of BaSO4 to bone volume. DTX administered on day 7 reduced tumor growth significantly (p < 0.05). Microdamage accumulation was found to be increased by the presence of metastases but was reduced by all treatments with ZA showing the largest improvement in HeLa cell injected rats. Load to failure was decreased in untreated and SBRT HeLa cell injected rats compared to healthy controls (p < 0.01). There was a moderate negative correlation between load to failure and microdamage volume fraction in vertebrae from rats injected with HeLa cells (R = -0.35, p = 0.031). Strong correlations were also found between microstructural parameters and load to failure and microdamage accumulation. Several factors, including the presence of osteolytic lesions and use of cancer therapies, influence microdamage accumulation and load to failure in rat vertebrae. Understanding the impact of these treatments on fracture risk of metastatic vertebrae is important to improve management of patients with spinal metastases.

Effect of chemotherapy and different chemotherapy regimens on bone health among Chinese breast cancer women in different menstrual status: a self-control study

PURPOSE

Although the therapy-related bone loss attracts increasing attention nowadays, the differences in chemotherapy-induced bone loss and bone metabolism indexes change among breast cancer (BC) women with different menstrual statuses or chemotherapy regimens are unknown. The aim of the study is to explore the effects of different regimens of chemotherapy on bone health.

METHOD

The self-control study enrolled 118 initially diagnosed BC women without distant metastasis who underwent dual-energy X-ray absorptiometry (DXA) bone mineral density (BMD) screening and (or) bone metabolism index monitoring during chemotherapy at Chongqing Breast Cancer Center. Mann-Whitney U test, Cochran's Q test, and Wilcoxon sign rank test were performed.

RESULTS

After chemotherapy, the BMD in the lumbar 1-4 and whole lumbar statistically decreased (- 1.8%/per 6 months), leading to a significantly increased proportion of osteoporosis (27.1% vs. 20.5%, P < 0.05), which were mainly seen in the premenopausal group (- 7.0%/per 6 months). Of the chemotherapeutic regimens of EC (epirubicin + cyclophosphamide), TC (docetaxel + cyclophosphamide), TEC (docetaxel + epirubicin + cyclophosphamide), and EC-T(H) [epirubicin + cyclophosphamide-docetaxel and/or trastuzumab], EC regimen had the least adverse impact on BMD, while the EC-TH regimen reduced BMD most (P < 0.05) inspite of the non-statistical difference between EC-T regimen, which was mainly seen in the postmenopausal group. Chemotherapy-induced amenorrhea (estradiol 94 pg/ml vs, 22 pg/ml; FSH 9.33 mIU/ml vs. 61.27 mIU/ml) was proved in premenopausal subgroup (P < 0.001). Except the postmenopausal population with calcium/VitD supplement, the albumin-adjusted calcium increased significantly (2.21 mmol/l vs. 2.33 mmol/l, P < 0.05) after chemotherapy. In postmenopausal group with calcium/VitD supplement, β-CTX decreased significantly (0.56 ng/ml vs. 0.39 ng/ml, P < 0.05) and BMD were not affected by chemotherapy (P > 0. 05). In premenopausal group with calcium/VitD supplement, PTH decreased significantly (52.90 pg/ml vs. 28.80 pg/ml, P = 0. 008) and hip BMD increased after chemotherapy (0.845 g/m2 vs. 0.952 g/m2, P = 0. 006). As for both postmenopausal and premenopausal group without calcium/VitD supplement, there was a significant decrease in bone mass in hip and lumbar vertebrae after chemotherapy (0.831 g/m2 vs. 0.776 g/m2; 0.895 g/m2 vs. 0.870 g/m2, P < 0.05).

CONCLUSION

Chemotherapy might induce lumbar vertebrae BMD loss and spine osteoporosis with regimen differences among Chinese BC patients. Calcium/VitD supplementation could improve bone turnover markers, bone metabolism indicators, and bone mineral density. Early interventions on bone health are needed for BC patients during chemotherapy.

Cytotoxic chemotherapy is associated with decreased bone mineral density in postmenopausal women with early and locally advanced breast cancer

PURPOSE

The burden and mechanisms of endocrine therapy-related bone loss have been studied in detail. However, there is limited data regarding cytotoxic chemotherapy's impact on bone health. There are no definitive guidelines for bone mineral density (BMD) monitoring and treatment with bone-modifying agents during cytotoxic chemotherapy. The study's primary objective was to evaluate the changes in BMD and fracture risk assessment tool (FRAX) scores among breast cancer women on cytotoxic chemotherapy.

METHODS

One hundred and nine newly diagnosed early and locally advanced postmenopausal breast cancer patients planned for anthracycline and taxane-based chemotherapy were recruited prospectively during the study period from July 2018 to December 2021. BMD of the lumbar spine, the femoral neck, and the total hip were assessed by dual-energy X-ray absorptiometry scan. BMD and FRAX scores were evaluated at baseline, end of chemotherapy, and 6 months of follow-up.

RESULTS

The median age of the study population was 53 (45-65) years. Early and locally advanced breast cancers were seen in 34 (31.2%) and 75 (68.8%) patients, respectively. The duration of follow-up between two BMD measurements was 6 months. The percentage of decrease in BMD at the lumbar spine, femoral neck, and total hip were - 2.36 ± 2.90, - 2.63 ± 3.79, and - 2.08 ± 2.80, respectively (P-value = 0.0001). The median risk of major osteoporotic fracture (MOF) at 10 years (FRAX score) increased from 1.7 (1.4) to 2.7% (2.4) (P-value = 0.0001).

CONCLUSION

This prospective study in postmenopausal breast cancer women shows a significant association of cytotoxic chemotherapy with the worsening of bone health in terms of BMD and FRAX score.