Topoisomerase II alpha and microtubuleassociated protein-tau as a predictive marker in axillary lymph node positive breast cancer

Aims and background. The aims of this study were to investigate the correlation between topoisomerase II alpha (TOP2A), microtubule-associated protein-tau (MAPtau) and other prognostic factors in breast cancer and to evaluate the predictive value of TOP2A and MAP-tau in breast cancer patients who received anthracycline and taxane-containing adjuvant chemotherapy. Methods and study design. Seventy patients with axillary lymph node positive breast cancer who underwent curative surgery between January 2000 and December 2005 were evaluated retrospectively. The levels of protein expression of TOP2A and MAPtau were assessed using immunohistochemistry. Results. Among the 70 patients, 43 (61.4%) showed TOP2A overexpression and 30 (42.9%) showed MAP-tau positivity. TOP2A overexpression was associated with p53 positivity and high histological grade. MAP-tau positivity was associated with a lower positive lymph node ratio, lower proliferative activity, and hormone receptor positivity. Based on the TOP2A and MAP-tau expression, there was no significant difference in disease-free survival in the breast cancer patients who received anthracycline and taxane-containing adjuvant chemotherapy. Conclusions. We conclude that immunohistochemical analysis of TOP2A and MAPtau protein expression may not predict the benefits of adjuvant anthracycline and taxane chemotherapy in axillary node positive breast cancer.