After adjusted by the effect of ER, our results indicate that breast tumors treated with DEC regimen achieved higher pathologic response than tumors treated with EFC or VFC regimen (DEC versus EFC, p = 0.044; DEC versus VFC, p = 0.030), while the pathologic response rate induced by VFC regimen was similar to that induced by EFC regimen (p = 0.495). The gene discussed is ESR1; the disease is breast neoplasm.