Abstract P4-16-10: Bone health in young women with breast cancer
Authors: KB Wendell, S Nadeem, B Martin, PM Camacho, KS Albain, P Robinson, SS Lo
Journal: Cancer Research (2019)

Abstract Introduction: There are limited data and consensus regarding bone mineral density (BMD) monitoring, and management of bone loss in younger women with breast cancer (BC). Adjuvant endocrine therapy for estrogen receptor positive (ER+) BC may include ovarian function suppression (OFS) plus use of aromatase inhibitors (AIs) for 5-10 years, both of which contribute to bone loss. The WHO risk prediction tool FRAX does not include BC or AI use as independent risk factors in its calculation thus underestimating risk of fracture. This study aims to evaluate current screening and management of bone health in young women with BC. Methods: A retrospective, IRB-approved chart review was performed in consecutive women ≤40 with BC diagnosed at Loyola University Chicago Medical Center between 01/01/2015 and 12/13/17. Demographic data, BC treatment, and factors contributing to secondary causes of bone loss were collected through 4/1/18. A descriptive analysis included summary values for all categorical and continuous risk factors. Results: BC ≤40yrs was identified in 136 women; 18 were excluded due to missing data. The analysis was performed on 118 patients (pts). Mean pt age was 34.6 yrs (SD 4.7). Stage at diagnosis included: stage 0 = 9 (7.6%), stage 1 = 26 (22%), stage 2 = 44 (37.3%), stage 3 = 23 (19.5%), stage 4 = 7 (5.9%), unknown = 9 (7.6%). Seventy-nine (67%) had ER+ BC; 32 (27.1%) had HER2-positive disease. The majority of pts (101, 85.6%) received chemotherapy in their treatment plan. Menopause was documented in 69 (59.0%) pts. Goserelin was used in 31 pts (44.9%), oophorectomy in 17 (24.6%), both in 5 (7.2%). Tamoxifen was used in 44 (55.7%) ER+ pts; 34 (43.0%) received an AI, and 18 (22.8%) received sequential tamoxifen and AI. 25 Hydroxy-Vitamin D (25 OHD) levels were checked in 61 (51.7%); 43 (70.5%) had levels &amp;lt;30 ng/ml; 24 (55.8%) received vitamin (vit) D supplementation. There was no difference in the 25 OHD in pre- and post-menopausal women (p=0.64). Pts with vit D deficiency had a median BMI of 26.8 vs 23.8 in those with sufficient vit D levels (exact p=.049). Secondary diagnoses contributing to low BMD were identified in 14 (11.8%). Dual energy xray absorptiometry (DXA) scans were checked in 23 pts (19.7%), 18 of whom were post-menopausal. At the femur, 0 pts had a z-score (age-matched standard deviation) of ≤-2.0, 9 pts (39.1%) had a score between 0 to -2.0. At the lumbar spine, 1 pt (4.3%) had a z-score ≤-2.0, 9 pts (39.1%) had a z-score between 0 to -2.0. No T-scores were in the osteoporosis range; 11 pts had T-scores at both femur and lumbar spine in the osteopenia range. The median 10 yr probability of a major osteoporotic fracture (FRAX score) was 1.9% (1.6-2.7%); the median 10 yr probability for hip fracture was 0.1% (0.10-0.20%). There were no differences in FRAX scores between pre- and post-menopausal women. No fractures were reported in the time period studied. Anti-resorptive therapy was used only in patients with metastatic bone disease. Conclusions: 25 OHD and DXA scans are not routinely checked in younger women diagnosed with BC. Vit D deficiency and evidence of bone loss is prevalent in those pts who do undergo testing. Further research and guidelines are necessary to address management of bone health in young women with BC to minimize future fracture risk and morbidity. Citation Format: Wendell KB, Nadeem S, Martin B, Camacho PM, Albain KS, Robinson P, Lo SS. Bone health in young women with breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-16-10.