乳がん経験者が監視下での骨形成負荷運動と高い順守度での生活習慣改善により骨粗しょう症を克服した症例報告

Breast cancer survivors are at elevated risk for osteoporosis due to chemotherapy-induced ovarian dysfunction, prolonged endocrine therapy, and premature menopause, and anti-resorptive therapy remains the standard of care even though some patients decline pharmacologic treatment. We describe a 55-year-old postmenopausal woman, treated 19 years earlier for stage II hormone receptor-positive, human epidermal growth factor receptor 2-positive ductal carcinoma of the right breast, who developed osteoporosis on routine screening. Treatment had included neoadjuvant chemotherapy, modified radical mastectomy, regional nodal irradiation, one year of trastuzumab, and 10 years of tamoxifen. A scan at age 41 had shown bone density within the expected range for age, but a repeat scan on Day -20 (relative to the start of the lifestyle intervention, defined as Day 0) demonstrated osteoporosis, with a total lumbar spine -score of -2.5, femoral neck -score of -2.1, and total hip -score of -1.9. She declined alendronate and began a structured lifestyle program on Day 0 consisting of weekly supervised osteogenic loading, progressive resistance training, increased aerobic activity, balance and mobility work, a whole-food plant-forward diet, and supplementation. A follow-up scan on Day 486 demonstrated a 4.3% increase in lumbar spine bone mineral density (-score -2.2), a 4.7% increase at the femoral neck (-score -1.8), and a 2.0% increase at the total hip (-score -1.8), with the most severely affected vertebrae recovering the most; calcium and vitamin D remained within target ranges throughout. Over approximately 16 months without anti-resorptive medication, this patient's lumbar spine moved from the osteoporotic to the osteopenic range, with concordant improvement at the femoral neck. Causality cannot be attributed to any single component of the intervention, but the case supports further study of structured lifestyle-based bone health strategies in breast cancer survivorship.