Current approaches and challenges in monitoring treatment responses in breast cancer

Monitoring response to treatment is a key element in the management of breast cancer that involves several different viewpoints from surgery, radiology, and medical oncology. In the adjuvant setting, appropriate surgical and pathological evaluation guides adjuvant treatment and follow up care focuses on detecting recurrent disease with the intention of improving long term survival. In the neoadjuvant setting, assessing response to chemotherapy prior to surgery to include evaluation for pathologic response can provide prognostic information to help guide follow up care. In the metastatic setting, for those undergoing treatment, it is crucial to determine responders versus non-responders in order to help guide treatment decisions. In this review, we present the current guidelines for monitoring treatment response in the adjuvant, neoadjuvant, and metastatic setting. In addition, we also discuss challenges that are faced in each setting.