The role of tumor marking prior to neoadjuvant chemotherapy and its relationship with pathologic response and surgical treatment of locally advanced breast cancer

Abstract

Patients with locally advanced breast carcinoma are candidates for the neoadjuvant chemotherapy. The majority of them have partial response to treatment, i.e., reduction in tumor size; however, the rate of pathological complete response is of only 24%, even with the association of anthracycline and taxane. One benefit of the neoadjuvant chemotherapy is the possibility of breast-conserving surgery, and the challenge is the accurate assessment of the tumor response degree to treatment. Clinical response is determined by physical exam and imaging studies, which are not sufficient to predict accurately the tumor size or the pathological complete response in relation to the golden-standard test, which is the surgical histopathology. Moreover, it is necessary to consider that after the neoadjuvant chemotherapy there may be tumor fragmentation, originating multifocal lesions, which are difficult to be detected by imaging methods. In studies regarding neoadjuvant chemotherapy, there is no uniformity in the type of test used for clinical and pathological assessments of tumor response, and there is no exact description of the methodology used in the preoperative markup of the tumor bed, which is not always resected after the neoadjuvant chemotherapy. This is a fact that hinders the accurate assessment of response to the neoadjuvant chemotherapy. Therefore, the question is: under which circumstances a breast-conserving surgery after neoadjuvant chemotherapy is well indicated? This article has discussed the different ways of tumor marking, the evaluation of pathological response and its importance, especially considering breast-conserving treatment of locally advanced breast carcinoma.