OBJECTIVETo investigate the relationship between Ki67 expression and tumor response to neoadjuvant chemotherapy with anthracyclines plus taxanes in breast cancer.

METHODSFrom January 2008 to June 2009, 129 patients with primary breast invasive ductal cancer received neoadjuvant chemotherapy with anthracyclines plus taxanes. The expression of Ki67 in the tumor tissues was determined by using immunohistochemistry with core needle biopsy specimens prior to the chemotherapy. The tumor response to the chemotherapy was evaluated by dynamic enhanced MRI based on RECIST2000 criteria, pathologic response was assessed according to Miller-Payne grading system, and the clinical comprehensive response was evaluated based on MRI combined with pathologic response.

RESULTSDynamic enhanced MRI classified 87 cases (67.4%) as effective. According to the Miller-Payne grading system, 99 cases (76.7%) were ranged effective. One hundred and ten cases (85.5%) were recognized as clinically comprehensive effective. The effective rates of neoadjuvant chemotherapy in patients with a Ki67 expression >10% evaluated by the above-mentioned three standards were 73.2%, 81.4% and 89.7%, respectively; and those in patients with a Ki67 expression < or = 10% were 50.0%, 62.5% and 71.9%, respectively. Compared with patients with a Ki67 expression < or = 10%, the patients with a Ki67 expression >10% had better response rates determined by all the three standards (P values were 0.020, 0.030 and 0.010, respectively). The Ki67 expression in the tumor tissue was linearly correlated with clinically comprehensive response on the Linear-Linear association analysis.

CONCLUSIONSThere is a statistic association between Ki67 expression and tumor response to the neoadjuvant chemotherapy with anthracyclines plus taxanes in breast cancer, and the patients with a higher expression of Ki67 has a better tumor response to the chemotherapy.