What neoadjuvant therapy will you give to a premenopausal woman with cT2N0 metaplastic triple negative breast cancer?

A stage 2 metaplastic TNBC is considered a high risk, relatively chemorefractory rare subtype case with limited data regarding optimal treatment. Multiple studies have shown metaplastic tumors demonstrate higher levels of PDL1. (Grabenstetter et al., PMID 34115674) Sylvia Adams has published some reports of checkpoint blockade activity in metaplastic breast cancer cases as well. For these reasons, I would try to use the KEYNOTE-522 regimen just approved by the FDA or clinical trial with immunoth...

I completely agree with Dr. @Dr. First Last. Given the high risk nature of her cancer and younger age, I would follow the KEYNOTE-522 regimen. We understand that metaplastic tumors are less responsive to chemotherapy but our current approach is to treat these tumors like non-metaplastic triple negative breast cancers. There is a good recent comprehensive review of metaplastic cancers (Reddy et al., PMID 33148288). Given the data regarding benefit from check point inhibitors in metaplastic breast...

I agree with the above comments (excluding Dr. @Dr. First Last's suggestion to give AC-T with pembrolizumab - omitting carboplatin would be a mistake as this is likely to reduce achievement of pCR and compromise long-term outcomes, based on results from a number of trials, including the one presented by Gupta et al. at SABCS 2022) about the use of the KEYNOTE-522 regimen for such a patient. While responses to neoadjuvant therapy in metaplastic triple-negative cancers are less predictable than in...