Objective: To investigate the effect of irradiation to anastomosis from preoperative radiotherapy for patients with rectal cancer by studying the pathological changes. Methods: In this retrospective study, patients enrolled in the FOWARC study from January 2011 to July 2014 in the Sixth Affiliated Hospital of Sun Yat-Sen University were included. In the FOWARC study, enrolled patients with local advanced rectal cancer were randomly assigned to receive either neoadjuvant chemo-radiotherapy or chemotherapy. Among these patients, 23 patients were selected as radiation proctitis (RP)group, who fulfilled these conditions: (1) received neoadjuvant chemo-radiotherapy followed by sphincter-preserving surgery; (2) developed radiation proctitis as confirmed by preoperative imaging diagnosis; (3) had intact clinical samples of surgical margins. Twenty-three patients who had received neoadjuvant chemo-radiotherapy but without development of radiation proctitis were selected as non-radiation proctitis (nRP) group. Meanwhile, 23 patients received neoadjuvant chemotherapy only were selected as neoadjuvant chemotherapy (CT) group. Both nRP and CT cases were selected by ensuring the basic characteristics such as sex, age, tumor site, lengths of proximal margin and distal margin all maximally matched to the RP group. Both proximal and distal margins were collected for further analysis for all selected cases. Microscopy slices were prepared for hematoxylin & eosin staining and Masson staining to show general pathological changes, and also for immunohistochemistry with anti-CD-34 as primary antibody to reveal the microvessel. Microvessel counting in submucosal layer and proportion of macrovessel with stenosis were used to evaluate the blood supply of the proximal and distal end of anastomosis. A modified semi-quantitative grading approach was used to evaluate the severity of radiation-induced injury. Either ANOVA analysis, Kruskal-Wallis rank-sum test or χ² test was used for comparison among three groups, and Mann-Whitney U test was used for comparison between two groups. Results: Compared to group of neoadjuvant chemotherapy only, patients receiving neoadjuvant chemo-radiotherapy had lower microvessel count in both proximal and distal margins (M(Q_R): proximal, 25.5 (19.6) vs. 50.0 (25.0), Z=3.915, P=0.000; distal, 20.5 (17.5) vs. 49.0 (28.0), Z=3.558, P=0.000), higher proportions of macrovessel with stenosis (proximal, 9.5% (23.8%) vs. 0, Z=3.993, P=0.000; distal, 11.5%(37.3%) vs. 0 (2.0%), Z=2.893, P=0.004), higher histopathologic score (proximal, 4.0 (2.0) vs. 1.0 (2.0), Z=6.123, P=0.000; distal, 5.0 (3.0) vs. 2.0 (1.0), Z=4.849, P=0.000). In patients receiving neoadjuvant chemo-radiotherapy, compared to nRP group, RP group had lower microvessel count in both proximal and distal margins (proximal, 19.0 (23.0) vs. 30.4 (38.0), Z=2.845, P=0.004; distal, 19.0 (13.0) vs. 30.0(29.1), Z=2.022, P=0.043), higher proportions of macrovessel with stenosis (proximal, 23.0% (40.0%) vs. 0(11.0%), Z=3.248, P=0.001; distal, 27.0% (45.0%) vs. 3.0% (19.0%), Z=2.164, P=0.030). Rate of anastomotic leakage for CT, nRP and RP group were 8.7% (2/23), 30.4% (7/23), and 52.2% (12/23), and the differences among three groups were statistically significant (χ²=10.268, P=0.007). Conclusion Radiation-induced injury existed on both margins of the resected rectal site after preoperative radiotherapy, and those diagnosed as radiation proctitis had more severe microvascular injury.

Objective: To investigate the safety and efficacy of surgical treatment for chronic radiation intestinal injury. Methods: A descriptive cohort study was performed. Clinical data of 73 patients with definite radiation history and diagnosed clinically as chronic radiation intestinal injury, undergoing operation at Department of Colorectal Surgery, the Sixth Affiliated Hospital of Sun Yat-sen University from January 1, 2012 to February 28, 2019, were reviewed and analyzed retrospectively. Patients did not undergo operation or only received adhesiolysis were excluded. All the patients had preoperative examination and overall evaluation of the disease. According to severity of intestinal obstruction and patients′ diet, corresponding nutritional support and conservative treatment were given. Surgical methods: The one-stage bowel resection and anastomosis was the first choice for surgical treatment of chronic radiation intestinal injury. Patients with poor nutritional condition were given enterostomy and postoperative enteral nutrition and second-stage stoma closure and intestinal anastomosis if nutritional condition improved. For those who were unable to perform stoma closure, a permanent stoma should be performed. Patients with severe abdominal adhesion which was difficult to separate, enterostomy or bypass surgery after adhesiolysis would be the surgical choice. For patients with tumor metastasis or recurrence, enterostomy or bypass surgery should be selected. Observation parameters: the overall and major (Clavien-Dindo grades III to V) postoperative complication within 30 days after surgery or during hospitalization; mortality within postoperative 30 days; postoperative hospital stay; time to postoperative recovery of enteral nutrition; time to removal of drainage tube. Results: Of the 73 patients who had been enrolled in this study, 10 were male and 63 were female with median age of 54 (range, 34-80) years. Preoperative evaluation showed that 61 patients had intestinal stenosis, 63 had intestinal obstruction, 11 had intestinal perforation, 20 had intestinal fistula, 3 had intestinal bleeding, and 6 had abdominal abscess, of whom 64(87.7%) patients had multiple complications. Tumor recurrence or metastasis was found in 15 patients. A total of 65(89.0%) patients received preoperative nutritional support, of whom 35 received total parenteral nutrition and 30 received partial parenteral nutrition. The median preoperative nutritional support duration was 8.5 (range, 6.0-16.2) days. The rate of one-stage intestine resection was 69.9% (51/73), and one-stage enterostomy was 23.3% (17/73). In the 51 patients undergoing bowel resection, the average length of resected bowel was (50.3±49.1) cm. Among the 45 patients with intestinal anastomosis, 4 underwent manual anastomosis and 41 underwent stapled anastomosis; 36 underwent side-to-side anastomosis, 5 underwent end-to-side anastomosis, and 4 underwent end-to-end anastomosis. Eighty postoperative complications occurred in 39 patients and the overall postoperative complication rate was 53.4% (39/73), including 39 moderate to severe complications (Clavien-Dindo grade III-V) in 20 patients (27.4%, 20/73) and postoperative anastomotic leakage in 2 patients (2.7%, 2/73). The mortality within postoperative 30 days was 2.7% (2/73); both patients died of abdominal infection, septic shock, and multiple organ failure caused by anastomotic leakage. The median postoperative hospital stay was 13 (11, 23) days, the postoperative enteral nutrition time was (7.2±6.9) days and the postoperative drainage tube removal time was (6.3±4.2) days. Conclusions Surgical treatment, especially one-stage anastomosis, is safe and feasible for chronic radiation intestine injury. Defining the extent of bowel resection, rational selection of the anatomic position of the anastomosis and perioperative nutritional support treatment are the key to reduce postoperative complications.

BACKGROUND:Increased homocysteine level induces apoptosis of human umbilical vein endothelial cells,but the mechanism remains unclear. OBJECTIVE:To investigate the role of hsa-circ-0001360 in human umbilical vein endothelial cell apoptosis induced by homocysteine. METHODS:In vitro cultured human umbilical vein endothelial cells were divided into control group,homocysteine group,interference control group,interference control + homocysteine group,hsa-circ-0001360 interference group,hsa-circ-0001360 + homocysteine interference group,overexpression control group,overexpression control + homocysteine group,hsa-circ-0001360 overexpression group and hsa-circ-0001360 + homocysteine overexpression group.All groups were treated with 100 μmol/L homocysteine.After 72 hours of intervention,the expressions of apoptosis-related proteins Bax,Bcl-2,and Caspase-3 were detected by western blot assay.The apoptotic rate was detected by flow cytometry.Quantitative real-time PCR was used to detect the expression of hsa-circ-0001360. RESULTS AND CONCLUSION:(1)Compared with the control group,the expression of Caspase-3 and Bax was significantly increased(P<0.01),and the expression of Bcl-2 was significantly decreased(P<0.01),and the apoptotic rate was significantly increased(P<0.01)in the homocysteine group.(2)Compared with control group,the expression of hsa-circ-0001360 was significantly increased in the homocysteine group(P<0.01).(3)The expression of hsa-circ-0001360 was significantly higher in the cytoplasm than that in the nucleus(P<0.01).(4)Compared with the interference control C group and interference control + homocysteine group,the expressions of Caspase-3 and Bax were significantly decreased(P<0.01),while the expression of Bcl-2 was significantly increased(P<0.01);the apoptotic rate was significantly decreased(P<0.01)in sh-hsa-circ-0001360 interference group and sh-hsa-circ-0001360 + homocysteine interference group.(5)Compared with overexpression control group and overexpression control + homocysteine group,the expressions of Caspase-3 and Bax were significantly increased(P<0.01),while the expression of Bcl-2 was significantly decreased(P<0.01);the apoptotic rate was significantly increased(P<0.01)in the hsa-circ-0001360 overexpression group and the hsa-circ-0001360 + homocysteine overexpression group.(6)In conclusion,hsa-circ-0001360 can promote the apoptosis of human umbilical vein endothelial cells induced by homocysteine.

OBJECTIVETo evaluate the short-term outcomes and perioperative safety of proximally extended resection for locally advanced rectal cancer after neoadjuvant chemoradiotherapy.

METHODSFrom colorectal cancer database in The Sixth Affiliated Hospital of Sun Yat-sen University, a cohort of patients who underwent neoadjuvant chemoradiotherapy(1.8-2.0 Gy per day, 25-28 fractions, concurrent fluorouracil-based chemotherapy) followed by curative sphincter-preserving surgery for locally advanced rectal cancer between May 2016 and June 2017 were retrospectively identified. Exclusion criteria were synchronous colon cancer, intraoperatively confirmed distal metastasis, multiple visceral resection, and emergency operation. Thirty-one patients underwent proximal extended resection and two were excluded for incomplete extended resection, then 29 patients were enrolled as the extended group. Using propensity scores matching with 1/1 ration, 29 locally advanced rectal cancer patients who underwent conventional resection after neoadjuvant chemoradiotherapy at the same time were matched as the conventional group. Clinical data of two groups were analyzed, and the baseline characteristics and short-term outcomes were compared using the t test, χtest, or Mann-Whitney U test.

RESULTSTwo groups were well balanced with respect to the baseline characteristics after propensity score matching. As compared with conventional group, patients in extended group had longer surgical specimen [(18.8±5.1) cm vs.(11.6±3.4) cm, t=6.314, P=0.000] and longer proximal resection margin [(14.8±5.5) cm vs.(8.2±3.0) cm, t=5.725, P=0.000], but also had longer total operating time [(322.4±100.7) min vs.(254.6±70.3) min, t=2.975, P=0.004] and more intraoperative blood loss [100(225) ml vs. 100(50) ml, Z=-2.403, P=0.016]. No significant differences were observed in the length of distal resection margin, ratio of positive resection margin, number of retrieved lymph node, time of analgesic use, time of draining tube use, time to first flatus, time to first oral diet, and postoperative hospital stay. During the perioperative period of 30 days, the morbidity of complication in extended group and conventional group was 17.2%(5/29) and 34.5% (10/29), respectively (P=0.134).

CONCLUSIONProximally extended resection is a radical and safe surgical alternative for locally advanced rectal cancer after neoadjuvant chemoradiotherapy, which can potentially reduce the risk of anastomosis complication.