1. Clinical nutritional support therapy is an important progress of modern medicine. 2. Conventional methods of clinical nutrition assessment (Anthropometric, lab, etc.) not just lack of accuracy and immediacy but also difcult to dynamic ally reflect the fluctuation trend of nutition status. 4. In the previous studies the investigators already found that apoptosis rate of oral mucosal epithelium could reflect changes in nutritional status There were an obvious decreasing in apoptosis and proliferation rate of oral mucosal epithelium in malnourished patients. 5. Based on the patient's curve of apoptosis rate of oral mucosal epithelium, the plateau being achieved by increase the nutition amount continuously, Maintain this amount of nutrition given until the end of treatment. The investigators call this amount of nutition the "upper limit nutrition support therapy". 6. The patients applying for'upper limit nutrition support therapy" and "Formula nutrition support therapy" separately, comparing of the two methods infuences on postoperative wound healing, postoperative complic ation rate ,inflammatory response, side effects of chemotherapy, hospital stays and hospitalization expenses.