Pre-treatment Elevated Platelet Count Associates with HER2 Overexpression and Prognosis in Patients with Breast Cancer

Purpose: To research the association between pre-treatment elevated platelet count and clinicopathologiccharacteristics in breast cancer (BC), as well as explore the relationship between pre-treatment elevatedplatelet count and HER2 status and prognosis of BC patients. Materials and
Methods: A retrospective cohortof BC patients who were newly diagnosed or treated by surgery only and had pathological detection resultsand platelet values in the Department of Oncology, the First Affiliated Hospital of Liaoning Medical Collegewere enrolled from 1/1/2008 until 31/12/2009, and followed up until 31/12/2014. Age, thrombocyte parametersbefore chemotherapy and/or radiotherapy, immunohistochemical (IHM) indexes, and regional lymph node(LN) involvement and progression-free survival (PFS) were recorded.
Results: A total of 447 eligible subjectswere included in this research. As we analyzed, for HER2, positive and negative, the incidence rates of elevatedplatelet count were 25.8% and 14.7% (P<0.05). In the Cox proportional hazards model both variables wereindependent risk factors for BC (for HER2, OR, 0.592, 95% confidence interval, CI, 0.355 to 0.985, P=0.044;f orPLT, OR, 0.998, 95% CI, 0.996 to 1.000, P=0.042). For ER, PR, Ki67 and LN involvement, the differences werenot statistically significant (P>0.05).
Conclusions: In this research, pre-treatment elevated level of platelet countdemostrated a significantrelationship with HER2 amplification/overexpression, and both variables significantlyinfluenced the prognosis of BC. However, elevated platelet count did not exhibit any association with ER, PR,Ki67 and LN involvement.