Augmented expression of Polo-like kinase 1 is a strong predictor of shorter cancer-specific overall survival in early stage breast cancer at 15-year follow-up.
Polo-like kinase 1 (PLK1) is a serine-threonine kinase that plays a crucial role in the regulation of cell division. In addition, it acts as a modulator of the DNA damage response and as a novel factor in the maintenance of genome stability during DNA replication. The present study aimed to reveal the associations between PLK1 expression and clinicopathological features of patients with breast cancer (BC), particularly patient survival at 5-, 10- and 15-year follow-up. PLK1 expression was evaluated immunohistochemically in routine diagnostic tissue specimens from 83 patients treated radically for stage II BC. Kaplan-Meier analysis revealed a correlation between PLK1 overexpression and long-term survival. High PLK1 immunoreactivity was associated with shorter cancer-specific overall survival (CSOS) and disease-free survival (P=0.00001 and 0.00013, respectively). Multivariate analysis confirmed the negative prognostic significance of PLK1 overexpression for CSOS in all 83 patients (P=0.00030). Furthermore, analogous correlations were observed in both subgroups with and without nodal metastases (P=0.01400 and 0.01200, respectively). The present results indicate that PLK1 expression has a prognostic role in early BC. Immunohistochemical assessment of PLK1 reactivity may potentially become a qualifier for inclusion of PLK1 inhibitor therapy.
Department of Pathomorphology and Oncological Cytology, Wroclaw Medical University, Wroclaw 50-556, Poland.
Piotr
P
Donizy
Department of Pathomorphology and Oncological Cytology, Wroclaw Medical University, Wroclaw 50-556, Poland.
Agnieszka
A
Halon
Department of Histology and Embryology, Wroclaw Medical University, Wroclaw 50-556, Poland.
Pawel
P
Surowiak
Department of Pathomorphology and Oncological Cytology, Wroclaw Medical University, Wroclaw 50-556, Poland.
Maciej
M
Kaczorowski
Department of Statistics, Wroclaw University of Economics, Wroclaw 53-345, Poland.
Cyprian
C
Kozyra
Department of Oncology and Surgical Oncology, Wroclaw Medical University, Wroclaw 50-556, Poland; Lower Silesian Oncology Centre, Breast Unit, Wroclaw 53-413, Poland.
Rafal
R
Matkowski
Polo-like kinase 1; breast cancer; prognosis; survival analysis