Purpose: 5-Fluorouracil (5-Fu) is used as a conventional chemotherapy drug in chemotherapy forpatients with advanced colorectal cancer, but many patients still suffer from treatment failuredue to 5-Fu resistance. Emerging observations revealed the important role of chemokine(C-X-C motif) ligand 13 (CXCL-13) in tumor microenvironment and its relationship with prognosisin patients with colorectal cancer. This study is designed to reveal the important roleof CXCL-13 in causing colorectal cancer resistance to 5-Fu. Materials and Methods: CXCL-13 levels of patient's serum or cell culture supernatants were measured separatelyby enzyme-linked immunosorbent assay. In cell assays, cell viability is detected by Cell CountingKit-8. Therefore, the recombinant human CXCL-13 was used to simulate its high expressionin cells while its antibody and siRNA were used to reduce CXCL-13 expression in cells. Results: In this study, we demonstrated that CXCL-13 is associated with 5-Fu resistance by culturemedium exchange experiments and cytokine arrays of colorectal cancer resistant and nonresistantcells. Clinical studies showed that CXCL-13 is highly expressed in the serum of5-Fu–resistant patients. High levels of serum CXCL-13 also predict a worse clinical outcome.The addition of recombinant CXCL-13 cytokine resulted in 5-Fu resistance, while its antibodyovercame 5-Fu resistance, and knockdown of CXCL-13 expression by siRNA also reduced5-Fu resistance, which can be saved by added recombination CXCL-13. Conclusion These results not only identify a CXCL-13 mediated 5-Fu resistance mechanism but alsoprovide a novel target for 5-Fu–resistant colorectal cancer in prevention and treatmentstrategies.

Objective:To examine the safety and effectiveness of a novel stent assisted intestinal bypass for preventing anastomotic leakage in laparoscopic assisted radical resection of rectal cancer.Methods:The clinical data of 9 patients with rectal cancer who underwent laparoscopic radical resection and stent assisted intestinal bypass from September 2019 to June 2020 at the Department of Anus & Intestine Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University were retrospectively analyzed. There were 6 males and 3 females, aged (62.1±6.8) years (range: 53 to 75 years), underwent laparoscopic assisted radical resection of rectal cancer and stent assisted intestinal bypass. A degradable diverting stent was placed at the end of the ileum, and a drainage tube was placed at the proximal end of the stent to bypass the intestinal contents. After operation, the patients were given a diet with less residue. From the 14 th day after operation, abdomen X-ray films were taken every 5 to 7 days to observe the destination of the stent dynamically. When the stent was observed to be disintegrated into pieces, the drainage tube was clamped for 3 days to observe any side effects before the tube was removed. The operation time, the time of removing the bypass tube and the total hospital stay were recorded. Results:Laparoscopic assisted radical resection of rectal cancer and stent assisted intestinal bypass were successfully performed in all patients. The operation time was (230.4±48.0) minutes (range: 150 to 318 minutes), and the time of removing shunt tube was (28.8±4.6) days (range: 22 to 34 days). The duration of hospitalization was (21.0±8.6) days (range: 9 to 34 days). Postoperative pathological examination showed 7 cases of moderately differentiated adenocarcinoma, 1 case of moderately well differentiated adenocarcinoma and 1 case of mucinous adenocarcinoma. There were 2 cases of T1, 4 cases of T2 and 3 cases of T3. The number of lymph node dissection was 13.4±3.5 (range: 6 to 18), 3 cases were positive and 6 cases were negative. The post-operation follow-up time was 6 to 16 months, no anastomotic leakage or stenosis was found.Conclusion:Stent assisted intestinal bypass for the prevention of anastomotic leakage in laparoscopic assisted radical resection of rectal cancer is safe and feasible, and shows good short-term effect.

Objective:To examine the safety and effectiveness of a novel stent assisted intestinal bypass for preventing anastomotic leakage in laparoscopic assisted radical resection of rectal cancer.Methods:The clinical data of 9 patients with rectal cancer who underwent laparoscopic radical resection and stent assisted intestinal bypass from September 2019 to June 2020 at the Department of Anus & Intestine Surgery, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University were retrospectively analyzed. There were 6 males and 3 females, aged (62.1±6.8) years (range: 53 to 75 years), underwent laparoscopic assisted radical resection of rectal cancer and stent assisted intestinal bypass. A degradable diverting stent was placed at the end of the ileum, and a drainage tube was placed at the proximal end of the stent to bypass the intestinal contents. After operation, the patients were given a diet with less residue. From the 14 th day after operation, abdomen X-ray films were taken every 5 to 7 days to observe the destination of the stent dynamically. When the stent was observed to be disintegrated into pieces, the drainage tube was clamped for 3 days to observe any side effects before the tube was removed. The operation time, the time of removing the bypass tube and the total hospital stay were recorded. Results:Laparoscopic assisted radical resection of rectal cancer and stent assisted intestinal bypass were successfully performed in all patients. The operation time was (230.4±48.0) minutes (range: 150 to 318 minutes), and the time of removing shunt tube was (28.8±4.6) days (range: 22 to 34 days). The duration of hospitalization was (21.0±8.6) days (range: 9 to 34 days). Postoperative pathological examination showed 7 cases of moderately differentiated adenocarcinoma, 1 case of moderately well differentiated adenocarcinoma and 1 case of mucinous adenocarcinoma. There were 2 cases of T1, 4 cases of T2 and 3 cases of T3. The number of lymph node dissection was 13.4±3.5 (range: 6 to 18), 3 cases were positive and 6 cases were negative. The post-operation follow-up time was 6 to 16 months, no anastomotic leakage or stenosis was found.Conclusion:Stent assisted intestinal bypass for the prevention of anastomotic leakage in laparoscopic assisted radical resection of rectal cancer is safe and feasible, and shows good short-term effect.