Objective: M30 and M65 levels reflect tumor cell activity in patients with epithelial cancer. Cytokeratin 18 is one of the cell skeletal elements. M30 is a apoptotic marker of cytokeratin 18. M65 levels are both an apoptosis and a necrosis marker. The aim of our study was to determine the predictive value of M30 and M65 levels in neoadjuvant treatment of breast cancer.