Key clinical point: Compared with female counterparts, male breast cancer patients had higher mortality that was explained in large part by clinical characteristics and undertreatment.

Major finding: Compared with women, men had higher overall mortality (adjusted hazard ratio, 1.19), 3-year mortality (adjusted hazard ratio, 1.15), and 5-year mortality (adjusted hazard ratio, 1.19).

Study details: Nationwide registry-based cohort study of 16,025 men and 1,800,708 women who received a breast cancer diagnosis between 2004 and 2014.

Disclosures: Dr. Shu disclosed no relevant conflicts of interest. One author was funded by the program of the China Scholarship Council.