Would multifocality impact your endocrine therapy recommendations for a female in her 20s with two foci of 1.7 mm HR+ HER2- IDC after bilateral mastectomy?

With two foci, both about 2 mm, the risk of distant metastases is very, very low. After bilateral mastectomy, the risk of local recurrence is, likewise, very, very low. So, even though this patient is in her 20s, the benefits of 'adjuvant' therapy probably don't outweigh the risks/side effects, and ...

Given the small size of her tumor foci (1.7 mm each) (I'm assuming that her axillary lymph nodes were negative for metastatic disease), her risk of occult metastatic disease - and thus distant recurrence - is very low and may not warrant any form of adjuvant endocrine therapy; and, having undergone ...

I apologize for missing that the tumor was T1a. I agree with the others.

Given only a pT1a tumor, both observation and endocrine therapy for 5 years are reasonable options. Given her young age pt may be wanting to try endocrine treatment even for the minimal benefit it will offer in her case. If she prefers to take endocrine therapy, I would agree with single-agent tamox...