Diagnosing and Prognosing Bone Metastasis in Prostate Cancer: Clinical Utility of Blood Biomarkers

Abstract Bone metastasis (BM) may occur in any type of cancer. The diagnosis of patients with BM has increased due to improved imaging technologies and advances in cancer drug therapy that have prolonged the survival time of cancer patients. BM may be asymptomatic in the early stages; however, as the disease progresses, it causes pain, fracture, neurological symptoms associated with spinal cord compression, hypercalcemia, and other specific symptoms that significantly impair the patient’s quality of life (QOL). Imaging modalities have disadvantages, such as high cost, radiation exposure, and bone pain associated with holding posture for imaging test; further, they are time-consuming. Hence, patients with BM require convenient and useful biomarkers. However, no blood biomarkers generally useful for diagnosis and therapeutic monitoring of BM are established. Prostate cancer (PC) and breast cancer, in particular, are among the most prone to BM because BM occurs in approximately 70% of patients with advanced disease. Herein, we reviewed various potential bone turnover markers and liquid biopsy for diagnosis and prognosis prediction in patients with BM of PC based on PubMed literature search. The usefulness of conventional bone turnover markers of BM in PC is limited, and cut-off values vary. In the future, the creation of algorithms using these conventional markers and multiple tests, such as liquid biopsy and imaging tests, will help to develop highly accurate techniques for the diagnosis of BM.