Chromogranin A: a useful biomarker in castration-resistant prostate cancer

Abstract

Purpose: The natural history of prostate cancer (PC) almost always evolves to castration-resistant prostate cancer (CRPC) status, sometimes comprising pure or mixed neuroendocrine prostate cancers (NEPC) differentiation. In CRPC, monitoring using only prostate-specific antigen (PSA) is not optimal since neuroendocrine differentiated cells do not secrete PSA. Thus, monitoring with PSA and chromogranin A (CgA) may be useful. This review aims to evaluate evidence for the usefulness of CgA assessments during the monitoring of prostate cancer. Method: This review was based on three recent meta-analysis concerning CgA and prostate cancer. Further data were obtained from PubMed and Embase databases by searches using keywords, including chromogranin A and prostate cancer. Results: CgA levels remain largely unchanged during the early PC evolution. The development of NEPC is characterised by lower PSA secretion and increased CgA secretion. Data supporting the prognostic value of high CgA baseline levels for survival are contrasting and scarce. However, increasing CgA levels early during treatment of metastatic (m)CRPC suggests resistance to treatment and predicts shorter survival, particularly in men with high baseline levels of CgA levels. In men with mCRPC, the first-line chemotherapy may be more appropriate than other agents when baseline CgA levels are high. Also, increasing CgA levels during treatment may indicate disease progression and may warrant a change of therapy. Conclusion: CgA monitoring at baseline and regularly during mCRPC management may be useful for monitoring disease evolution. An increased CgA baseline levels and increasing CgA levels may assist physicians with choosing and modifying therapy.