How would you approach adjuvant endocrine therapy after excision of a hormone positive recurrence after mastectomy who finished 5 years of aromatase inhibitor for the same primary tumor in the context of NATALEE and MonarchE trials?

The key question is whether this is an endocrine-sensitive or endocrine-resistant disease. If this recurrence happened after discontinuation of endocrine therapy, then most likely it is because of withdrawing therapy that was effectively suppressing the disease. This is not an uncommon scenario, and while the evidence for extended endocrine therapy is mixed, in this type of situation it is a signal that extended endocrine therapy is most appropriate. View it as an opportunity to be informed about the biology of disease in an individual patient and a second chance to extend an effective treatment since the clinical recurrence is only local. You get a break in a way.

If this recurrence occurred while the patient is ON endocrine therapy, then t...