The role of preoperative systemic treatment in patients with breast cancer.

The goal of preoperative pharmacotherapy in patients with breast cancer is to enable breast conserving surgery in stage T3N0-1M0 or radical mastectomy in patients with primary inoperative tumors (T1-4N0-3M0). The choice of optimal treatment should be based not only on risk factors resulting from the stage but also on predicted cancer responsiveness to the treatment. The breast cancer subtypes defined by immunohistochemical profile (expression of ER, PR, HER2 and Ki67) are characterized by different responsiveness to therapy.

Prognostic value of HER3, PTEN and p-HER2 expression in patients with HER2positive breast cancer.

Background: HER2 overexpression is an unfavorable prognostic factor in patients with breast cancer, but it is also a target for the monoclonal antibody trastuzumab, which is effective in adjuvant and palliative settings. HER2 positivity is an inclusion criterion for immunotherapy, but it is not a positive predictive factor, and only half of patients benefit from the treatment.

Aim: The aim of this study was to evaluate the prognostic and predictive value of HER3, PTEN and phosphorylated HER2 (p-HER2) expression in primary breast tumors of patients treated with trastuzumab in an adjuvant or palliative regimen.