Abstract P5-11-05: Examining bone degeneration as a side effect of treatment in premenopausal breast cancer patients

Abstract

Abstract Background: Although it is widely known that adjuvant treatments cause osteoporosis in postmenopausal women, the effect of treatment and the exact degree of bone loss in premenopausal women is not well understood. For this reason, this study examined the relationship between the changes of bone mineral density(BMD) and the types of treatment in premenopausal breast cancer patients. Method: This retrospective study looks at preoperative and annual spine bone densitometry tests conducted on breast cancer patients during their observational period following initial treatment for their diagnosis. 461 premenopausal patients who received treatment from January 2006 to April 2007 were the study cohort because of the availability of bone mineral density (BMD) data (L-spine and femur T scores) for a two-year period. The data from the patients were separated into groups according to their treatment plans: observation, adjuvant chemotherapy, adjuvant chemotherapy followed by use of Tamoxifen, and GnRHa(Gonadotropin Releasing Hormone agonist) followed by Tamoxifen. Results: Of the 461 patients, 21 received no treatment aside from surgery, 75 received only Tamoxifen, 34 only chemotherapy, 166 chemotherapy and Tamoxifen, and 165 Zoladex and Tamoxifen. The no treatment group demonstrates the standard annual change in BMD. At first year, the chemotherapy only group and tamoxifen after chemotherapy group showed significant bone loss in the first year (p<0.005, both). The patients who received tamoxifen alone or tamoxifen with goserelin showed decrease BMD but not significant. After 2 years, tamoxifen with goserelin group showed significant decreased BMD in both spine and femur (p<0.001, p=0.001, both). Chemotherapy group showed partial recovery from the first year bone loss. Conclusion: The patients who received chemotherapy or GnRHa as treatment showed the greatest degree of bone degeneration but at different periods. However, Tamoxifen used along with these treatments seemed to lessen the extent of bone degeneration. Significant bone loss from hormone treatment occurred two years after surgery as compared to one year for chemotherapy. Citation Format: Kim M, Kim HJ. Examining bone degeneration as a side effect of treatment in premenopausal breast cancer patients [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-11-05.