Estrogen receptors, hormonal imbalance, gynecomastia, hyperestrogenemia, and male breast cancer: a literature review

Abstract

Male breast cancer (MBC) is a rare, malignant tumor. It occurs in men where it accounts for less than 1% of all breast cancers. This is linked with the hormonal imbalance of estrogen and androgen levels. The objective of this review is to provide the details about pathophysiology of gynecomastia (GM) caused by estrogen hormone imbalance along with the explanation of hyperestrogenemia caused by excessive estrogen, the treatment, the adjuvant, and preventive management of MBC currently used by clinical research. Treatment, prevention, and management strategies for MBC follow the similar protocols as for female breast cancer, but today’s treatment strategies include hormone-manipulating chemotherapy and biologics. The use of gene metabolites or active isomers, hormonal therapy and resection are also illustrated in clinical cases. Regarding the treatment and prevention of MBC, it is expected that the treatment strategies will shift to personalized medicine in the future, as it is difficult to identify mutant genes and perform effective genetic screening. Nevertheless, through our narrative review, this article discusses the differences between male and female breast cancer, the relationship between male hormones and breast cancer, and potential future treatment strategies.

Keywords

• male breast cancer
• estrogen
• gynecomastia
• hyperestrogenemia