The prognostic value of Ki67 in systemically untreated patients with node-negative breast cancer.

Aim: To evaluate the utility of Ki67 as a prognostic marker in a series of patients with node-negative breast cancer untreated with adjuvant systemic therapy.

Methods: The cohort consisted of 203 cases treated with breast conserving surgery and radiation only; median follow-up was 183 months (range 156-277 months). An immunohistochemical panel of oestrogen receptor (ER), progesterone receptor (PR), cytokeratin (CK)5/6 and Ki67 and human epidermal growth factor 2 in situ hybridization (HER2-ISH) was performed on the tumour samples.