MP51-09 CHARACTERIZING TESTOSTERONE AND BONE DENSITY PROFILES OF MEN AFTER STEM CELL TRANSPLANT

Abstract

INTRODUCTION AND OBJECTIVES: Over 18,000 Stem Cell Transplants (SCT) are performed each year. Such patients routinely receive gonadotoxic therapies. Chemotherapy, total body irradiation (TBI), and chronic steroid use are well-recognized causes of Leydig cell damage. Our aim was to characterize total testosterone (TT) profiles of men who underwent SCT, and identify any correlations between decline in T and subsequent diagnosis of decreased bone density. METHODS: All men who underwent an allogeneic SCT at a single institution in the past 15 years who had at least one TT level measured within 90 days prior to their SCT and one within three years following their treatment were included. Men who were on T replacement therapy pre-SCT were excluded. Bone densitometry (DXA) was performed per institution standard of care guidelines. Descriptive statistics are provided and a within subjects t-test was used to compare pre and post T values. RESULTS: 32 men were included. Mean age 1⁄4 55 14 (range 24-71) years. 28% died a mean of 14 8 months post SCT. 100% of patients received at least one alkylating agent, and 63% received two alkylating agents as part of their chemotherapy regimen. The most common chemotherapeutic regimens were Fludarabine/Busulfan/ Melphalan (38%), Thiotepa/Cyclophosphamide (16%), and Fludarabine/Melphalan (13%). 28% received TBI in addition to their chemo. 100% of patients were on long-term or intermittent corticosteroids. Mean T pre-SCT 1⁄4 401 154, post-SCT 1⁄4 389 205 ng/dL, p1⁄40.65. Pre-SCT, 66% had TT levels >300, and 47% had TT levels 200ng/dL decrease after treatment. Mean LH was 12.9 (SD 8.2) at 13 months post-SCT. On DXA, 42% had a diagnosis of osteopenia or osteoporosis. 6% of men had a documented non-pathologic fracture during study follow-up period, all of whom had post-SCT TT levels <150 ng/dL. CONCLUSIONS: Men post-SCT are at a significant risk for testosterone deficiency and bone mineral density loss. There is evidence of testicular damage early after SCT. The fracture risk appears greatest in men with the lowest TT levels post-SCT.