Yakup Ergün, Medical Oncologist at Antalya City Hospital, shared an article on X:
“I think this was one of the most important datasets for breast oncologists at ASCO26: the ET-use analysis in the HR+/HER2+ cohort of HER2CLIMB-05.
In HER2CLIMB-05, PFS curves in HR+ patients who received ET appear to be maintained for a longer period, with a lower rate of early progression. In contrast, the curve in patients who did not receive ET starts to decline earlier and more prominently.
This was not an ET-randomized analysis. So it would be methodologically wrong to say directly that ‘ET improved PFS.’ But the direction of the curves is highly consistent with the biology of HR+/HER2+ disease: Suppressing HER2 while leaving the ER axis untreated may represent undertreatment, particularly in the maintenance setting.
PATINA provides the cleanest comparison here. In PATINA, ET was not the question; it was the backbone. All patients received anti-HER2 therapy plus ET. Even the control arm included ET. Palbociclib was added on top of this backbone and improved PFS from 29.1 to 44.3 months.
So one of the key messages of PATINA was not only ‘add a CDK4/6 inhibitor.’ The more fundamental message was this: In HR+/HER2+ metastatic breast cancer, the biological backbone of maintenance therapy should be anti-HER2 therapy plus ET.
HER2CLIMB-05 reminds us of the same point from another angle. Disease control appears to be maintained longer in patients receiving ET, while early progression seems more evident in those not receiving ET.
In my view, maintenance treatment in HR+/HER2+ metastatic breast cancer should no longer be thought of simply as ‘continue anti-HER2 therapy.’
Anti-HER2 therapy is the backbone. But the ER axis should not be left untreated.
In this patient group, maintenance ET should not be viewed as an optional add-on; omitting it should require a clear clinical justification.”
FAST-Forward 10-Year Results Support 1-Week Breast Radiotherapy As Standard Of Care
