A low proportion of regulatory T cells before chemoradiotherapy predicts better overall survival in esophageal cancer

Growing evidence indicates that survival is correlated with immune status in certain types of solid tumors. The immune system functions either to eliminate cancer cells or to keep cancer cells in check by maintaining an equilibrium; if there is a malfunction in the immune system, immune escape may happen which then allows cancer cells to grow into clinically apparent tumors. The progression of the tumor leads to a poor prognosis. Regulatory T cells (Tregs), a subset of CD4+ T cells plays a pivotal role in regulating the immune system. Tregs were identified as being CD4+ T cells expressing high levels of CD25. The purpose of this study was to investigate the influence of the proportion of pretreatment regulatory T cells (CD45+CD4+CD25HICD127LOW) on the prognosis of patients with non-operative chemoradiotherapy for esophageal cancer (EC).