In a retrospective study by Akram Yazdani et al., carcinoembryonic antigen (CEA) and CA-153 levels were not significantly different in breast cancer patients with or without bone metastasis, and serum concentrations of alkaline phosphatase (ALP) (OR = 1.005) were an independent risk factor associated with bone metastases [60]. Here, CEACAM5 is linked to breast cancer.