Abstract: 〗［Abstract］〓Objective〖HTSS〗〓To analyze the effect of stent implantation combined with neoadjuvant chemotherapy on the surgical outcome and malignant biological behavior of the patients with obstructive leftsided obstructing colon cancer.
〖HTH〗〖WTHZ〗Methods〖HTSS〗〓The clinical data of 81 patients with acute intestinal obstruction caused by left colon cancer were retrospectively analyzed. According to the different treatment methods，there were 42 cases in the control group and 39 patients in the experimental group. The control group underwent radical open colon resection for colon cancer. The experimental group were received the chemotherapy after the stent was implanted, and the delayed radical colon surgery .The serum samples were taken to detect the level of tumor markers, and tumor tissues were taken to detect the expression of malignant molecules. The blood loss during operation, the number of lymph nodes, the time from operation to exhaust, the incidence of intestinal anastomosis leakage the condition of stage one resection and complete anastomosis, and the infection rate of incision were compared between the two groups.
〖HTH〗〖WTHZ〗Results〖HTSS〗〓The levels of serum carcinoembryonic antigen(CEA), CA724, CA199 and CA125 in the control group were significantly lower than those before the operation(P＜005). The levels of serum CEA, CA724, CA199 and CA125 in the experimental group were significantly lower than those before the operation, the levels of serum CEA, CA724, CA199 and CA125 were significantly lower than those after chemotherapy(P＜005). The levels of serum CEA, CA724, CA199 and CA125 in the experimental group were significantly lower than those in the control group(P＜005). After surgical resection, the mRNA expression levels of the SMYD3, CHD1L， osteopontin and Survivin in the experimental group was significantly lower than those in the control group(P＜005). In the experimental group, the time of operation, the amount of blood lost during operation, the incidence of anastomotic leakage, and the incidence of incision infection were significantly lower than those in the control group， the rate of one stage anastomosis after resection was significantly higher than that of control group(P＜005).
〖HTH〗〖WTHZ〗Conclusion〖HTSS〗〓Obstructive left colon cancer with stent implanted to relieve the obstruction and followed by neoadjuvant chemotherapy and then radical mastectomy can effectively reduce the biological malignancy of tumor tissue and inhibit the malignant molecular expression of malignant biological behavior, reduce tumor grading and staging, and effectively avoid emergency surgery, thus reduce the risk of surgery, increase the surgical effect, and eventually benefiting.

Key words: colonic neoplasms, intestinal obstruction, intestinal stent, chemoradiotherapy, adjuvant