Would you add neoadjuvant pembrolizumab to chemotherapy in a premenopausal female with T2N1 breast cancer that is weakly ER or PR positive?  

I would not give neoadjuvant pembrolizumab. Although cancers like the one described tend to behave more like triple negative cancers than hormone receptor positive ones, the KEYNOTE-522 study defined triple negative by the ASCO-CAP guidelines which (without knowing the details of this patient's path...