What is your approach to systemic therapy in patients with ER+ HER2- breast cancer with invasion of the pectoralis muscle on imaging without overt chest wall involvement?

I would send the diagnostic biopsy for Oncotype DX testing - if it returns at 26 or higher, I would give neoadjuvant chemo and hope that the tumor shrinks back from the pectoralis. If it is 25 or less, we would consider neoadjuvant endocrine therapy. If this is ineffective would leave it up to her s...

In patients with hormone receptor-positive, HER2-negative early-stage breast cancer whose primary tumor demonstrates apparent invasion of the pectoralis muscle on imaging — without involvement of other chest wall structures, per the AJCC 8th Edition TNM staging system as incorporated in the NCCN Bre...

In cases of hormone receptor-positive, HER2-negative, nonmetastatic but locally advanced breast cancer, neoadjuvant systemic therapy is recommended to facilitate surgery. The specific answer to this question, though, depends on the patient's menopausal status/age and whether or not the surgery team ...