Supportive Therapy for Bone Density Loss due to Aromatase Inhibitors

Abstract

The effect of supportive therapy on bone density loss was investigated in 87 postmenopausal breast cancer patients who received an aromatase inhibitor (AI) for five years as postoperative adjuvant therapy. Before administering AI, bone density was measured at two sites : the lumbar spine and femoral neck. An active vitamin D3 preparation (D3) was concurrently administered with AI in patients with a lower T score (≤-1.0) while a bisphosphonate (Bis) or denosumab preparation was concurrently administered in those with a T score ≤-0.25. They were re-evaluated every year to adjust the supportive therapy accordingly. The bone density change rates at five years were -6.11%, -3.11%, and +5.04% in patients without supportive therapy at the beginning of AI administration (n=42), those with concomitant D3 administration (n=34), and those with concomitant Bis administration (n=11), respectively, indicating that the bone density improved even under AI treatment with concurrent Bis administration. Examination of the clinical risk factors for bone density loss demonstrated that bone density significantly reduced in patients who received AI before the age of 60, indicating that more attention should be paid regarding when AI is administered to patients immediately after menopause.