The role of neoadjuvant chemotherapy: 1.It helps to lower the tumor stage and make the surgery convenient and smooth. 2, late stage inoperable can be chemotherapy, control systemic metastasis, so that patients with tumor survival. Extend the survival period. 3.Used before, during and after surgery to improve the effect of surgery as a local treatment. 4.Kill systemic micrometastases and avoid distant metastases. 5.Part of comprehensive treatment.