Effect of Adjuvant Chemotherapy is Responsible for Decreasing Segmental and Total BMD in BC Postmenopausal Women

Background: Women with breast cancer are at increased risk for the development of osteoporosis and skeletal fractures, as consequences of aromatase inhibition or chemotherapy-induced ovarian failure. We investigated the effect of adjuvant chemotherapy on biochemical markers of bone formation and resorption as well as on bone mineral density (BMD) of non-metastatic breast cancer (NMBC) postmenopausal Egyptian women. Methods: We followed 100 newly diagnosed women with T1-3 N0-2 M0 breast cancer, who had a mean age (±SD) of 55.06±8.78 year, before and after receiving 6-cycles of CAF chemotherapy treatment protocol. All participant women were subjected to blood biochemical analysis for determining serum levels of: erythrocyte sedimentation rate, calcium, alkaline phosphatase (ALP), bone specific alkaline phosphatase (S.ALP), Osteocalcin, carboxytelopeptide of collagen type I (CTx-I), 25-Hydroxyvitamin D, Parathyroid Hormone (PTH) and tumor marker CA15-3. Segmental and total BMD were also investigated using Dual X-ray Absorptiometry technique. Results: We found ALP, S.ALP, and CTx-I levels were significantly lower (p<0.001), while PTH levels to be significantly higher for all women after chemotherapy as compared to their initial state before chemotherapy. Both segmental and total BMD, and consequently T- and Z-Scores after chemotherapy were significantly (p<0.01) lower than their levels before chemotherapy. We developed prediction mathematical formulae for spine, pelvis and total BMD for all women before and after chemotherapy. Conclusions: Adjuvant chemotherapy is responsible for decreasing both biochemical markers of bone formation and resorption as well as for decreasing segmental and total BMD in NMBC postmenopausal Egyptian women. We believe the mathematical formulae developed on basis of the two individual variables Age and BMI can be useful for assisting the clinician to frequently monitor bone health status of breast cancer patients in similar conditions.