Modified reck dissection should be preformed,if the diameter of the tumer is over 1. 5cm,whether the lymph node preoperativcly and inrtaoperativcly is palpable or not.

• （2）原发肿瘤直径超过1.；5cm者无论术前和术中是否摸到肿大淋巴结，均需作改良淋巴结清扫。