- Unlike female breast cancer, higher histological grade of male breast cancer is not associated with OS.
- Other histological features are associated with OS, similar to female breast cancer.
Why this matters
- Findings suggest more research is needed to enable risk stratification of male patients, which affects treatment decisions.
- 1483 male breast cancer specimens were collected from 1990 to 2010 through the European Organisation for Research and Treatment of Cancer (EORTC).
- Central pathology review focused on histological subtype, grade, mitotic activity index (MAI), presence of a fibrotic focus, and density of tumor-infiltrating lymphocytes (TILs).
- Histological characteristics were correlated with clinical outcome.
- Funding: Breast Cancer Research Foundation, the Dutch Pink Ribbon, the European Breast Cancer Council, and Susan G. Komen for the Cure.
- Overall histological grade was not significantly correlated with OS (P=.129).
- MAI (P=.023), the presence of fibrotic focus (P=.004), and low TIL density (P=.011) were, similar to female breast cancer, correlated with unfavorable OS.
- There was no association between subtype and fibrotic focus.
- Treatments were not highly standardized, which could have confounded findings.