In ER-negative and HER2-negative MedBC, the risk of recurrence and death was significantly lower than that of IDC, about half. Postoperative chemotherapy reduced recurrence and mortality. ER-positive and HER2-negative MedBC may have a lower risk of recurrence compared to IDC.
Patients with ER-positive MBC had greater odds of receiving quality end-of-life care than those with ER-negative MBC. HER2 status was not associated with differences in the quality of end-of-life care.