Significance of hormone therapy & bisphosphonate use on vertebral compression fracture (VCF) incidence following spine stereotactic body radiation therapy (SBRT) for breast cancer metastases.

Introduction: Spinal metastases are increasingly being treated with SBRT. Though effective, a potential toxicity of SBRT is VCF. Breast cancer (BC) is one of the most common primary sites to metastasize to the spine, & due to factors such as HT use, these patients may be at higher risk for VCF following SBRT. Our study aimed to determine the rate of SBRT induced VCF (S-VCF) in BC patients, & to understand if there is a significant relationship between hormone therapy (HT) & bisphosphonate (Bp) use on this risk. Materials/Methods: 335 vertebral bodies (VB) (nZ131 patients) were treated with spine SBRT for BC metastases at a single institution between 06/2001 & 12/2014. EMRs were retrospectively reviewed in this IRB approved study, & data on the use of Bp, Selective Estrogen Receptor Modulators (SERMs), & Aromatase Inhibitors (AIs) were recorded. Development of a new VCF, progression of an existing VCF & requirement of stabilization surgery after SBRT were the primary endpoints of this study. These were evaluated using CT & MRI. Only VCF development/ progression occurring in VB treated with SBRT were considered. VBs with concurrent tumor progression, or surgery prior to SBRT were not included. Statistical significance of VCF incidence, & the use of Bp & HT concurrent with, within 6 m, 1 yr, & 2 yrs of SBRT, was evaluated using the Chi-Square Test for Independence, & Fisher\u27s Exact Test. Results: Follow up was available for 91 patients (69%) & 233 VB. Median survival post SBRT was 21 m. 58.8% of patients were Caucasian, 33.6% African American, & 7.6% were of other ethnicities. Bone density was low in 59% of patients. Median SBRT dose was 18 Gy/1 fx. Median tumor volume was 35.83 cc. Median follow-up was 15.6 m. 33 VCFs in 20 patients were observed. 48% were new, 24% progressed, & 27% were VB that required surgical stabilization after SBRT. The overall S-VCF rate was 14%. 70 patients (192 VB), 50 patients (146 VB), & 78 (221 VB) were exposed to AIs, SERMs, & Bp, with S-VCF rates of 14.6%, 14%, & 13% respectively. The following were found to be statistically significant in relation to S-VCF: SERM use concurrent (p= .003), within 6 m of (p= .028), & within 2 yrs of (p= .021) SBRT. Also significant was Bp use within 1 yr of SBRT (p\u3c .0001). AI use was not found to be statistically significant for any of the time frames evaluated in our study. Conclusions: Rate of developing a VCF in our cohort was 14%. The overall rate of S-VCF in BC patients is not considerably higher than rates previously reported in non-histology specific series. We will further analyze our cohort to better understand the protective or adverse effects of HT & Bp use in BC patients receiving spine SBRT. To the best of our knowledge, this is the only reported series analyzing S-VCF in BC with an emphasis on the relation of Bp & HT use. Elshaikh M, Ghanem AI, Schaugle S, and Burmeister C. The impact of adjuvant therapies on survival for women with state II endometrial carcinoma. Int J Radiat Oncol Biol Phys 2018; 101(2):E31. Objectives: To report survival outcomes in women with stage II uterine non-endometrioid carcinoma (NEC) after surgical staging with various adjuvant management options using the National Cancer Database (NCDB). Methods: The NCDB was queried for women with 2009 International Federation of Gynecology and Obstetrics (FIGO) stage II uterine NEC diagnosed from 2004 to 2012 who underwent hysterectomy followed by adjuvant management [active surveillance, radiation treatment (RT) or chemotherapy (CT)]. Chi-squared tests were performed to compare differences in outcome by type of adjuvant management. Overall survival (OS) was assessed by Kaplan-Meier and log-rank tests. Univariate and multivariate analyses were performed to identify statistically significant predictors of OS. Results: We identified 1238 women who met our inclusion criteria. The median follow-up time was 51.5 months. Simple hysterectomy was performed in 1009 women (82%) with lymph node dissection performed in 1004 women (81%). Median number of dissected lymph nodes was 13. 35% of patients were diagnosed with carcinosarcoma. Adjuvant RT was used in 49% of patients and CT in 45%. On multivariate analysis of OS, old age, African-American race, no or fewer number of examined LNs, carcinosarcoma and not receiving any adjuvant therapies were independent predictors of worse OS. For those patients who received adjuvant RT with CT, administering CT first was associated with a better 5-year OS compared to those who received RT first (PZ0.02). The 5-year OS for the entire cohort was 65%. Conclusions: In this nationwide hospital-based study of women with FIGO stage II uterine non-endometrioid carcinoma, adjuvant radiation and chemotherapy improved overall survival. The sequence of administering chemotherapy before radiation treatment was associated with a better overall survival