Triple positive breast cancer: a distinct subtype?

•HER-2, ER and PgR have a key role in treatment decision making in breast cancer.•Triple positive (TP) tumours exhibit a unique clinical and biological behavior.•TP breast cancer behavior might be also driven by HR status.•TP tumors with low disease burden and high HR expression resemble luminal tumours.•The identification and characterization of this subset may avoid overtreatment.