CYP27A1 and breast cancer: When the group of BC patients considered for this study was segregated into subgroups on the basis of the existence of metastases, the urine α-CTx values (p = 0.001) for both urine α-CTx (μg/mL) and urine α-CTx (μg/mmol Cr) were found to be substantially higher in BC patients suffering from metastases.