How long would you keep a patient on endocrine/dual anti HER-2 therapy after resection of a late (>5 years) oligometastatic recurrence of ER+ HER2+ breast CA?

I have struggled with this a few times. The handful of times I have discontinued her 2 directed treatment, there has been recurrence within a year and then it took chemotherapy plus her 2 directed therapy to achieve remission. It is now my practice to continue endocrine+her 2 directed therapy till p...