Correlation between bone mineral density and endometrial thickness over time in women with breast cancer history

As the efficacy of chemotherapy and adjuvant endocrine therapy for breast cancer increase, the quality-of-life to cancer survivors could be more important issue in strategies of breast cancer treatment. Bone health has become more compelling in care of breast cancer survivor than ever before. This retrospective study was aimed to evaluate factors relating to the change in BMD and to ascertain the correlation between changes in BMD and EMT of women with breast cancer in follow-up. Records of 164 women who underwent surgery for breast cancer were reviewed in this study. The basal characteristics included parity, menopausal state, medication with vitamin D, bisphosphonate, selective estrogen modulator (SERM), aromatase inhibitor (AI), gonadotrophin releasing hormone agonist (GnRHa), chemotherapy, radiotherapy, cancer type including positivity of estrogen receptor, progesterone receptor and HER2, combined the other gynecologic disease or the other origin cancer. At initial and follow-up visit, all subjective were checked with BMD, endometrial thickness (EMT). The mean age was 52.1 ± 8.5 years old and overall interval between initial and follow-up visits were 17.6 ± 7.5 month in this study. The BMDs of L1–4 (1.040 ± 0.166 g/cm² vs 1.070 ± 0.181 g/cm², p < 0.001), femur neck (0.850 ± 0.121 g/cm² vs 0.870 ± 0.136 g/cm², p < 0.001), and femur total (0.902 ± 0.132 g/cm² vs 0.915 ± 0.138 g/cm², p < 0.001) at follow-up visit were significantly lower than those at initial visit. The change in BMDs of L1–4 (ΔBMD_L1–4, r = 0.353, p < 0.001, and r = 0.228, p = 0.003), femur neck (ΔBMD_Neck, r = 0.198, p = 0.011, and r = 0.282, p < 0.001), femur total (ΔBMD_Total, r = 0.294, p < 0.001, and r = 0.327, p < 0.001) had positive correlation with age and the change in EMT (ΔEMT). After age correction, ΔEMT had positive correlation with ΔBMD_Neck (r = 0.245, p = 0.002) and ΔBMD_Total (r = 0.273, p < 0.001). ΔBMD_L1–4 and ΔBMD_Neck differed according to menopausal state (p < 0.001 and p = 0.035), bisphosphonate (p < 0.001 and p < 0.001), and GnRHa (p < 0.001 and p < 0.001). In follow-up of women with history of breast cancer, ΔEMT could be an alternative screening marker for BMD decrease.