Roles of neutrophil/lymphocyte ratio (NLR) and platelet/lymphocyte ratio (PLR) in prognosis and in differentiation of potential beneficiaries in HER2-positive breast cancer with trastuzumab therapy

HER2 is an oncogene and is associated with aggressive tumor growth and poor prognosis. Oncogene is a kind of gene having the potential to cause a normal cell to become cancerous or to strengthen the ability of invasion and metastases of cancerous cell. HER2 is over-expressed in 20-25% of all invasive breast cancer (BC). Trastuzumab (Herceptin®) is an effective therapy for HER2 over-expression BC and can decrease the risk of relapse around 25%. Meanwhile, the situation that HER2-positive BC have no response to trastuzumab treatment exists indeed. The mechanism of trastuzumab resistance is not yet understood, and there is no factor that could predict the sensitivity to trastuzumab of HER2-positive breast cancer.