A recent comprehensive study has offered new insights into the role of human epidermal growth factor 2 (HER2) in male breast cancer (MBC), an area that has been poorly defined until now. Researchers analysed data from 6,015 MBC patients across 45 studies, alongside sequencing data from 135 MBC patients, to assess HER2 positivity and its impact on overall survival (OS).
The study found that approximately 10% of MBC patients tested positive for HER2, with a prevalence that varied across regions. Notably, Asian MBC patients had the highest incidence, with 17% testing positive for HER2. Furthermore, 7% of patients exhibited HER2 protein overexpression, while 10% had gene amplification or overexpression.
When considering survival outcomes, the study showed that HER2-positive MBC patients had significantly worse OS, with a hazard ratio of 1.92, indicating nearly double the risk of poorer survival compared to HER2-negative patients. This suggests the importance of HER2 status as a key prognostic factor in male breast cancer.
The study also revealed distinct genomic differences between HER2-positive MBC and HER2-positive female breast cancer (FBC), though certain altered genes were exclusive to MBC cases. The authors concluded that assessing HER2 status in MBC may require a multifaceted approach, as the prevalence and implications of HER2 positivity in male breast cancer differ from that of women.
This research is a crucial step towards better understanding and potentially improving treatment strategies for male breast cancer patients.
Helena Bradbury, EMJ
Reference
Lyu B et al. HER2 expression and pathway status in male breast cancer patients: results of an integrated analysis among 6,150 patients. Sci Rep. 2025;15(1):3354.
