Residual disease and immune infiltration as a new surrogate endpoint for TNBC post neoadjuvant chemotherapy

Triple negative breast cancer (TNBC) is distinguished from other breast cancer subtypes by its lack of therapeutic targets, aggressive biology, and poorest survival rates. In the early breast cancer setting, cytotoxic chemotherapy remains the mainstay of systemic treatment options. Multiple clinical trials and meta-analyses have demonstrated that patients who achieve a pathological complete response (pCR) to neoadjuvant chemotherapy (NAC) have an excellent prognosis Therefore, NAC is now extensively used for early stage TNBC (and HER2positive breast cancer) to improve prognostic stratification, but also in the setting of residual disease, to enrich for high risk, treatment resistant patients that may benefit from treatment escalation or change of systemic therapy Reported rates of pathologic complete response (pCR) to neoadjuvant chemotherapy (NAC) regimens in TNBC