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 clinicopathologic characteristics in breast cancer (BC), as well as explore the relationship between pre-treatment elevated platelet count and HER2 status and prognosis of BC patients.

Materials And Methods: A retrospective cohort of BC patients who were newly diagnosed or treated by surgery only and had pathological detection results and platelet values in the Department of Oncology, the First Affiliated Hospital of Liaoning Medical College were enrolled from 1/1/2008 until 31/12/2009, and followed up until 31/12/2014. Age, thrombocyte parameters before 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 subjects were included in this research. As we analyzed, for HER2, positive and negative, the incidence rates of elevated platelet count were 25.8% and 14.7% (P<0.05). In the Cox proportional hazards model both variables were independent risk factors for BC (for HER2, OR, 0.592, 95% confidence interval, CI, 0.355 to 0.985, P=0.044;f or PLT, OR, 0.998, 95% CI, 0.996 to 1.000, P=0.042). For ER, PR, Ki67 and LN involvement, the differences were not statistically significant (P>0.05).

Conclusions: In this research, pre-treatment elevated level of platelet count demostrated a significantrelationship with HER2 amplification/overexpression, and both variables significantly influenced the prognosis of BC. However, elevated platelet count did not exhibit any association with ER, PR, Ki67 and LN involvement.