[Robotics should be the mainstream surgical approach in gastrointestinal surgery]

The clinical application of robotic gastrointestinal surgery has made significant progress during the past 20 years. Increasing research have demonstrated that the robotic gastrointestinal surgery is safe and feasible, with the advantages in lymph node dissection, precise manipulation in narrow space, intraoperative suturing, and achieves satisfactory clinical outcomes. However, it also face challenges such as high costs, lack of high quality studies, and limited intelligent level. With the advancement of more high-quality evidence-based medical research and the development of new intelligent surgical robots, the robotic gastrointestinal surgery will be further standardized. We believe that the robotic surgery will become the mainstream of surgical treatment for gastrointestinal surgery.

Long-term oncological outcomes of robotic versus laparoscopic gastrectomy for gastric cancer: multicentre cohort study

BACKGROUND

The aim of this multicentre cohort study was to compare the long-term oncological outcomes of robotic gastrectomy (RG) and laparoscopic gastrectomy (LG) for patients with gastric cancer.

METHODS

Patients with gastric cancer who underwent radical gastrectomy by robotic or laparoscopic approaches from 1 March 2010 to 31 December 2018 at 10 high-volume centres in China were selected from institutional databases. Patients receiving RG were matched 1 : 1 by propensity score with patients undergoing LG. The primary outcome was 3-year disease-free survival. Secondary outcomes were overall survival and disease recurrence.

RESULTS

Some 2055 patients who underwent RG and 4309 patients who had LG were included. The propensity score-matched cohort comprised 2026 RGs and 2026 LGs. Median follow-up was 41 (i.q.r. 39-58) months for the RG group and 39 (38-56) months for the LG group. The 3-year disease-free survival rates were 80.8% in the RG group and 79.5% in the LG group (log rank P = 0.240; HR 0.92, 95% c.i. 0.80 to 1.06; P = 0.242). Three-year OS rates were 83.9 and 81.8% respectively (log rank P = 0.068; HR 0.87, 0.75 to 1.01; P = 0.068) and the cumulative incidence of recurrence over 3 years was 19.3% versus 20.8% (HR 0.95, 0.88 to 1.03; P = 0.219), with no difference between groups.

CONCLUSION

RG and LG in patients with gastric cancer are associated with comparable disease-free and overall survival.

Novel combined endoscopic and laparoscopic surgery for advanced T2 gastric cancer: Two case reports

BACKGROUND

The standard treatment for advanced T2 gastric cancer (GC) is laparoscopic or surgical gastrectomy (either partial or total) and D2 lymphadenectomy. A novel combined endoscopic and laparoscopic surgery (NCELS) has recently been proposed as a better option for T2 GC. Here we describe two case studies demonstrating the efficacy and safety of NCELS.

CASE SUMMARY

Two T2 GC cases were both resected by endoscopic submucosal dissection and full-thickness resection and laparoscopic lymph nodes dissection. This method has the advantage of being more precise and minimally invasive compared to current methods. The treatment of these 2 patients was safe and effective with no complications. These cases were followed up for nearly 4 years without recurrence or metastasis.

CONCLUSION

This novel method provides a minimally invasive treatment option for T2 GC, and its potential indications, effectiveness and safety needs to be further evaluated in controlled studies.

[Future prospect of robotic gastric cancer surgery]

Robotic gastric cancer surgery developed rapidly in recent years and its future prospect has received continuous attention. Compared with traditional laparoscopy, robotic surgery has obvious technical advantages and superior efficacy. Although some problems and deficiencies still exist, robotic gastric cancer surgery will be further popularized with more high-quality evidence-based medicine research and the development of new domestic surgical robots, and therefore bring greater benefits for more patients. We believe that robotic gastric cancer surgery will become the mainstream of minimally invasive surgery for gastric cancer.

[Comparison of clinical efficacy and quality of life between uncut Roux-en-Y and Billroth II with Braun anastomosis in laparoscopic distal gastrectomy for gastric cancer]

Objective: To compare the clinical efficacy and quality of life between uncut Roux-en-Y and Billroth II with Braun anastomosis in laparoscopic distal gastrectomy for gastric cancer patients. Methods: A retrospective cohort study was performed. Inclusion criteria: (1) 18 to 75 years old; (2) gastric cancer proved by preoperative gastroscopy, CT and pathological results and tumor was suitable for D2 radical distal gastrectomy; (3) postoperative pathological diagnosis stage was T1-4aN0-3M0 (according to the AJCC-7th TNM tumor stage), and the margin was negative; (4) Eastern Cooperative Oncology Group (ECOG) physical status score <2 points, and American Association of Anesthesiologists (ASA) grade 1 to 3; (5) no mental illness; (6) able to answer questionnaires independently; (7) patients agreed to undergo laparoscopic distal gastrectomy and signed an informed consent. Exclusion criteria: (1) patients with severe chronic diseases and American Association of Anesthesiologists (ASA) grade >3; (2) patients with other malignant tumors; (3) patients suffered from serious mental diseases; (4) patients received neoadjuvant chemotherapy or immunotherapy. According to the above criteria, clinical data of 200 patients who underwent laparoscopic distal gastrectomy at the Department of General Surgery of the First Affiliated Hospital of Army Medical University from January 2016 to December 2019 were collected. Of the 200 patients, 108 underwent uncut Roux-en-Y anastomosis and 92 underwent Billroth II with Braun anastomosis. The general data, intraoperative and postoperative conditions, complications, and endoscopic evaluation 1 year after the surgery were compared. Besides, the quality of life of two groups was also compared using the Chinese version of the European Organization For Research and Treatment of Cancer (EORTC) quality of life questionnaire-Core 30 (QLQ-C30) and quality of life questionnaire-stomach 22 (QLQ-STO22). Results: There were no significant differences in baseline data between the two groups (all P>0.05). All the 200 patients successfully underwent laparoscopic distal gastrectomy without intraoperative complications, conversion to open surgery or perioperative death. There were no significant differences between two groups in operative time, intraoperative blood loss, postoperative complications, time to flatus, time to removal of gastric tube, time to liquid diet, time to removal of drainage tube or length of postoperative hospital stay (all P>0.05). Endoscopic evaluation was conducted 1 year after surgery. Compared to Billroth II with Braun group, the uncut Roux-en-Y group had a significantly lower incidences of gastric stasis [19.8% (17/86) vs. 37.0% (27/73), χ(2)=11.199, P=0.024], gastritis [11.6% (10/86) vs. 34.2% (25/73), χ(2)=20.892, P<0.001] and bile reflux [1.2% (1/86) vs. 28.8% (21/73), χ(2)=25.237, P<0.001], and the differences were statistically significant. The EORTC questionnaire was performed 1 year after surgery, there were no significant differences in the scores of QLQ-C30 scale between the two groups (all P>0.05), while the scores of QLQ-STO22 showed that, compared to the Billroth II with Braun group, the uncut Roux-en-Y group had a lower pain score (median: 8.3 vs. 16.7, Z=-2.342, P=0.019) and reflux score (median: 0 vs 5.6, Z=-2.284, P=0.022), and the differences were statistically significant (all P<0.05), indicating milder symptoms. Conclusion: The uncut Roux-en-Y anastomosis is safe and reliable in laparoscopic distal gastrectomy, which can reduce the incidences of gastric stasis, gastritis and bile reflux, and improve the quality of life of patients after surgery.

[Effect of peritoneum reconstruction on postoperative complications after laparoscopic low anterior resection for rectal cancer]

Objective: To determine the effect of peritoneum reconstruction on postoperative complications after laparoscopic low anterior resection (LAR) for rectal cancer. Methods: Retrospective cohort study and propensity score matching were conducted. Case inclusion criteria: (1) pathologically confirmed rectal adenocarcinoma; (2) 18 to 80 years; (3) patients with middle to low rectal cancer undergoing laparoscopic LAR; (4) patients staging cT1-4aN0-2M0 or ycT1-4aN0-2M0 after neoadjuvant therapy; (5) the distance of 4-10 cm from tumor low margin to anal verge. Exclusion criteria: (1) abdominal surgery history (except appendicitis, cholecystitis, ectopic pregnancy); (2) anastomosis above the peritoneal reflection; (3) tumor distant metastasis or clinical staging of T4b during surgery; (4) conversion to open surgery; (5) severe incapacitating disease (American Society of Anesthesiologists classification IV or V, ASA). A total of 666 patients with middle to low rectal cancer undergoing laparoscopic LAR in The First Affiliated Hospital of Army Medical University from January 2017 to June 2020 were enrolled. There were 473 males and 193 females with the median age of 59 (18-80) years. Laparoscopic LAR with peritoneum reconstruction was performed in 188 cases (PR group), and laparoscopic LAR without peritoneum reconstruction was performed in 478 cases (NPR group). After 1:1 propensity score matching according to 1:1 based on age, gender, body mass index, TNM staging, ASA classification, intraoperative blood loss, distance from tumor low margin to anal edge, 153 cases were included in each group. Postoperative complications were classified according to Clavien-Dindo classification. Anastomotic leakage was defined and graded according to the International Study Group of Rectal Cancer (ISGRC) criteria. Results: After propensity score matching, there were no significant differences in baseline demographic characteristics between the 2 groups (all P>0.05), indicating that these two groups were comparable. (1) Operative conditions: All the patients in both groups completed operation successfully. Compared with the NPR group, the PR group had longer operation time [(181.3±60.3) minutes vs. (168.9±51.5) minutes, t=2.185, P=0.029], shorter postoperative median hospital stay [8 (7, 10) days vs. 9 (7, 11) days, Z=-2.282, P=0.022], and the differences were statistically significant (P<0.05). (2) Postoperative complications: The overall morbidity of postoperative complication in PR group and NPR group was 20.3% (31/153) and 24.2% (37/153) respectively, and the incidence of anastomotic leakage was 9.8% (15/153) and 11.1%(17/153) respectively, whose differences were not statistically significant (both P>0.05). Compared with NPR group, PR group had lower morbidity of grade III to IV complications [3.9% (6/153) vs. 11.1% (17/153), χ(2)=5.688, P=0.017] and lower secondary operation rate [1.3% (2/153) vs. 5.9% (9/153), χ(2)=4.621, P=0.032], the differences were statistically significant (both P<0.05). Though PR group had lower incidence of grade C anastomoic leakage [1.3% (2/153) vs. 3.9% (6/153), χ(2)=2.054, P=0.152], but the differences were not statistically significant. (3) Postoperative inflammation: The difference of the procalcitonin level of both PR and NPR groups at postoperative 1-d, 3-d, and 5-d was statistically significant (F=5.222, P=0.010) in time-dependent manner, while the difference was not significant in the interaction effect (P>0.05). No statistically significant differences in the C-reactive protein level between two groups at postoperative 1-d, 3-d, and 5-d were found (all P>0.05). Conclusion: Peritoneum reconstruction in laparoscopic LAR can decrease the morbidity of postoperative complication of grade III to IV and the reoperation rate, and plays an important role in controlling the inflammatory reaction, which has great clinical value.

Robotic total gastrectomy for carcinoma in the remnant stomach: a comparison with laparoscopic total gastrectomy

Background

Total gastrectomy for carcinoma in the remnant stomach (CRS) remains a technically demanding procedure. Whether robotic surgery is superior, equal, or inferior to laparoscopic surgery in patients with CRS is unclear. This study was designed to compare the efficacy and safety of robotic total gastrectomy (RTG) and laparoscopic total gastrectomy (LTG) for the treatment of CRS.

Methods

In this cohort study, we retrospectively analysed the data from patients who underwent RTG or LTG for CRS at Southwest Hospital (Chongqing, China) between May 2006 and October 2019. The surgical outcomes, post-operative complications, and survival outcomes between the two groups were compared.

Results

Compared with LTG, RTG was associated with similar effective operation time (272.0 vs 297.9 min, P = 0.170), higher total costs (105,967.2 vs 81,629.5 RMB, P < 0.001), and less estimated blood loss (229.2 vs 288.8 mL, P = 0.031). No significant differences were found between the robotic and laparoscopic groups in terms of conversion rate, time to first flatus, time to first soft diet, post-operative hospital stay, post-operative complications, R0 resection rate, and number of retrieved lymph nodes (all P > 0.05). The 3-year disease-free survival and 3-year overall survival rates were comparable between the two groups (65.5% vs 57.5%, P = 0.918; 69.0% vs 60.0%, P = 0.850, respectively).

Conclusions

RTG is a safe and feasible procedure for the treatment of CRS and could serve as an optimal treatment for CRS.

Short-Term Clinical Efficacy of Neoadjuvant Chemotherapy Combined With Laparoscopic Gastrectomy for Locally Advanced Siewert Type II and III Adenocarcinoma of the Esophagogastric Junction: A Retrospective, Propensity Score-Matched Study

Background

Laparoscopic gastrectomy (LG) has been increasingly used for the treatment of locally advanced Siewert type II and III adenocarcinoma of the esophagogastric junction (AEG). However, whether LG can achieve the same short-term efficacy in the treatment of patients who receive neoadjuvant chemotherapy (NACT) remains controversial. Thus, the aim of this study was to investigate the clinical outcomes of NACT combined with LG for Siewert type II and III AEG.

Methods

This retrospective study identified patients with locally advanced Siewert type II and III AEG diagnosed between May 2011 and October 2020 using the clinical tumor-node-metastasis (cTNM) staging system. The short-term outcomes were compared between the matched groups using a 1:3 propensity score matching (PSM) method, which was performed to reduce bias in patient selection.

Results

After PSM, 164 patients were selected, including 41 in the NACT group and 123 in the LG group. The baseline characteristics were similar between the two groups. Compared with the LG group, the NACT group exhibit a smaller tumor size and significantly less advanced pathological tumor classification and nodal classification stages. The time to first flatus of the NACT group was significantly shorter, but the hospital stay was significantly longer than that of the LG group. The NACT group showed similar overall (29.3% vs 25.2%, P=0.683), systemic (24.4% vs 21.1%, P=0.663), local (12.2% vs 9.8%, P=0.767), minor (19.5% vs 19.5%, P=1.000) and major (9.8% vs 5.7%, P=0.470) complications as the LG group. Subgroup analyses showed no significant differences in most stratified parameters. Operation time≥ 300 minutes was identified as an independent risk factor for overall complications. Age≥ 60 years was identified as an independent risk factor for major complications.

Conclusion

NACT combined with LG for AEG does not increase the risk of postoperative morbidity and mortality compared with LG.

Comparison of the Postoperative Complications Between Robotic Total and Distal Gastrectomies for Gastric Cancer Using Clavien-Dindo Classification: A Propensity Score-matched Retrospective Cohort Study of 726 Patients

BACKGROUND

This study was designed to compare the postoperative complications after Robotic total gastrectomy (RTG) and robotic distal gastrectomy (RDG) and to systematically evaluate the safety and feasibility of RTG for the treatment of gastric cancer (GC).

METHODS

Patients with GC who underwent RTG or RDG for curative intent between March 2010 and August 2019 were analyzed. We used propensity score matching (PSM) to reduce selection bias. The morbidity and mortality within 30 days after surgery between the RTG and the RDG groups were compared.

RESULTS

According to Clavien-Dindo (C-D) classification, the morbidity and mortality of the RTG group were comparable to those of the RDG group. Subgroup analyses showed no significant difference between the RTG and RDG groups in all stratified parameters (all P > .05). Multivariate analysis revealed that age ≥70 years (P = .002) and surgeons' experience ≤25 cases (P = .013) were independent risk factors for overall complication. Surgeons' experience ≤25 cases (P = .010) was identified as an independent risk factor for severe complication.

CONCLUSION

RTG is a safe and feasible surgical procedure for the treatment of GC with acceptable morbidity and mortality. More complications were observed for RTG, indicating that RTG is more invasive than RDG.

Laparoscopic versus open gastrectomy for serosa-invasive gastric cancer: A single-center retrospective cohort study

BACKGROUND

Whether laparoscopic gastrectomy is suitable for patients with serosa-invasive gastric cancer remains controversial. We performed this study to evaluate the short- and long-term outcomes after laparoscopic gastrectomy compared with after open gastrectomy.

METHODS

We retrospectively analyzed 906 consecutive patients with serosa-invasive gastric cancer from January 2004 to December 2014 in our center, who underwent laparoscopic gastrectomy or open gastrectomy with D2 lymphadenectomy. After propensity score matching, 334 patients were included in each group. Surgical conditions and short- and long-term results were compared.

RESULTS

Laparoscopic gastrectomy was associated with less estimated blood loss and longer operation time, while the number of harvested lymph nodes was not significantly different between laparoscopic gastrectomy and open gastrectomy. Patients who underwent laparoscopic gastrectomy had an earlier time to first flatus, first diet, and first ambulation and were discharged earlier. Overall and pulmonary postoperative complication rates were lower in the laparoscopic gastrectomy group. With a minimum follow-up of 60 months, the 5-year overall survival was 39.3% in the laparoscopic gastrectomy group and 34.3% in the open gastrectomy group, and the 5-year disease-free survival was 36.4% in the laparoscopic gastrectomy group and 32.7% in the open gastrectomy group. Laparoscopic gastrectomy was associated with better 5-year overall survival in patients aged ≥60 years. The overall recurrence rates and patterns were not significantly different between the 2 groups.

CONCLUSION

Laparoscopic gastrectomy is an alternative surgical approach for patients with serosa-invasive gastric cancer in terms of short-term outcomes and long-term survival, and it might be more advantageous for certain populations.

Long-term oncologic outcomes of robotic versus laparoscopic gastrectomy for locally advanced gastric cancer: a propensity score-matched analysis of 1170 patients

BACKGROUND

The robotic surgical system has several technical advantages over laparoscopic instruments. The technical feasibility and safety of robotic gastrectomy (RG) for gastric cancer have been reported by increasing number of studies. However, the long-term survival and recurrence outcomes after RG for locally advanced gastric cancer (AGC) have seldom been reported. This study aimed to compare long-term oncologic outcomes for patients with locally AGC after RG or laparoscopic gastrectomy (LG).

METHODS

This study comprised 1170 patients underwent RG or LG, respectively, for locally AGC between March 2010 and February 2017. The primary outcome was the 3-year disease-free survival (DFS). The secondary endpoint included 3-year overall survival (OS) and recurrence patterns. One-to-one propensity score matching (PSM) was performed to reduce confounding bias. The outcomes were compared in PSM cohort.

RESULTS

After PSM, a well-balanced cohort of 816 patients (408 in each group) were included in the analysis. The 3-year DFS rate was 76.2% in the robotic group and 70.1% in the laparoscopic group (P = 0.076). The 3-year OS rates was 76.7% in the robotic group and 73.3% in the laparoscopic group (P = 0.246). In the subgroup analyses for potential confounding variables, neither 3-year DFS nor 3-year OS survival were significantly different between the two groups (all P > 0.05). The two groups showed similar recurrence patterns within 3 years after surgery (P > 0.05).

CONCLUSION

For patients with locally AGC, RG can result in comparable long-term survival outcomes without an increase in recurrence rate.

Reappraise role of No. 10 lymphadenectomy for proximal gastric cancer in the era of minimal invasive surgery during total gastrectomy: a pooled analysis of 4 prospective trial

BACKGROUND

For patients with locally advanced proximal gastric cancer (LAPGC), the individualized selection of patients with highly suspected splenic hilar (No. 10) lymph node (LN) metastasis to undergo splenic hilar lymphadenectomy, is a clinical dilemma. This study aimed to re-evaluate the feasibility and safety of laparoscopic spleen-preserving splenic hilar lymphadenectomy (LSPSHL) and to identify the population who would benefit from it.

METHODS

A total of 1068 patients (D2 group = 409; D2 + No. 10 group = 659) who underwent laparoscopic total gastrectomy from four prospective trials between January 2015 and July 2019 were analyzed.

RESULTS

No significant difference in the incidence (16.9% vs. 16.4%; P = 0.837) of postoperative complications were found between the two groups. The metastasis rate of No. 10 LN among patients in the D2 + No. 10 group was 10.3% (68/659). Based on the decision tree, patients with LAPGC with tumor invading the greater curvature (Gre), patients with non-Gre-invading LAPGC with a tumor size > 5 cm and clinical positive locoregional LNs were defined as the high-priority No. 10 dissection group. The metastasis rate of No. 10 LNs in the high-priority group was 19.4% (41/211). In high-priority group, the 3-year overall survival of the D2 + No. 10 group was better than that of the D2 group (74.4% vs. 42.1%; P = 0.005), and the therapeutic index of No. 10 was higher than the indices of most suprapancreatic stations.

CONCLUSIONS

LSPSHL for LAPGC is safe and feasible when performed by experienced surgeons. LSPSHL could be recommended for the high-priority group patients even without invasion of the Gre.

[Long-term efficacy of robotic radical total gastrectomy for gastric cancer and analysis of prognostic factors]

Objective: To analyze long-term outcomes and prognostic factors of gastric cancer patients after robotic radical total gastrectomy. Methods: A retrospective case-control study was conducted. Inclusion criteria: (1) receiving robotic radical total gastrectomy; (2) gastric adenocarcinoma was confirmed by postoperative pathology; (3) no previous history of other malignant tumors; (4) no preoperative chemotherapy or radiation therapy performed. Exclusion criteria: (1) age <18 years old or age >80 years old;(2)distant metastasis before surgery, or palliative surgery; (3) conversion to laparotomy;(4) R1 or R2 resection; (5)emergency surgery; (6) remnant gastric cancer or recurrence; (7)died of severe complications during hospitalization or within 1 month after surgery. Overall survival rates (OS) and disease-free survival rates (DFS) were evaluated using the Kaplan-Meier method. Cox regression analysis was used to identify prognosis factors for overall survival. Results: According to the above criteria, 166 gastric cancer patients who underwent robotic radical total gastrectomy between March 2010 and November 2018 were included in this study. Roux-en-Y reconstruction was performed in all patients. Reconstruction were achieved using extracorporeal method through a minilaparotomy in 149 case and intracorporeal anastomosis in 17 cases. The number of harvested lymph nodes was (34.8±17.5), and the number of harvested lymph nodes at group 2 was (10.1±6.7). The number of patients with lymph node metastasis of group 2 was 73 (44.0%). The median follow-up time was 25 months (range 2-109). There were 55 (33.1%) cases of recurrence during follow-up. The 3- and 5-year overall survival rates were 55.8% and 46.2% respectively. The 3- and 5-year disease-free survival rates were 53.4% and 45.4% respectively. The 5-year overall survival rates grouped based on TNM stage were 78.9% for stage I, 58.5% for stage II, and 37.1% for stage III. The 5-year disease-free survival rates grouped based on TNM stage were 78.9% for stage I, 59.2% for stage II, and 34.6% for stage III. Univariate analysis suggested that TNM stage, the number of harvested lymph nodes and number of harvested lymph nodes at group 2 were associated with overall survival rates (all P<0.05). Multivariate analyses revealed that TNM stage (P<0.001; stage IIIB: HR=5.357, 95%CI:1.182 to 24.275; stage IIIC: HR=11.937, 95%CI: 2.677 to 53.226) and number of harvested lymph nodes at group 2 (P=0.034; 6-10: HR=0.562,95%CI:0.326 to 0.969; >10: HR=0.388, 95%CI: 0.176 to 0.857) were independent prognostic factors for overall survival. Conclusion: The long-term outcomes of robotic radical total gastrectomy were satisfactory. TNM stage and number of harvested lymph nodes at group 2 were independent prognostic factors for overall survival.

International consensus on natural orifice specimen extraction surgery (NOSES) for gastric cancer (2019)

At present, natural orifice specimen extraction surgery (NOSES) has attracted more and more attention worldwide, because of its great advantages including minimal cutaneous trauma and post-operative pain, fast post-operative recovery, short hospital stay, and positive psychological impact. However, NOSES for the treatment of gastric cancer (GC) is still in its infancy, and there is great potential to improve its theoretical system and clinical practice. Especially, several key points including oncological outcomes, bacteriological concerns, indication selection, and standardized surgical procedures are raised with this innovative technique. Therefore, it is necessary to achieve an international consensus to regulate the implementation of GC-NOSES, which is of great significance for healthy and orderly development of NOSES worldwide.

[Analysis on the technical characteristics and clinical efficacy of robotic-assisted intersphincteric resection for patients with low rectal cancer]

Objective: To explore the technical characteristics and short-term clinical efficacy of robotic-assisted intersphincteric resection (ISR) for patients with low rectal cancer. Methods: A retrospective cohort study was used. Inclusion criteria: (1) rigid colonoscopy showed lower margin of the tumor ≤5 cm from the anal verge; (2) preoperative rectal MRI or endorectal ultrasound revealed staging T1-2, or T3 patients receiving concurrent chemoradiotherapy; (3) patients less than 70 years old with good function of anal sphincter before surgery; (4) no synchronous multiple primary carcinoma, and no distant metastasis; (5) the method of operation was agreed by the patient. Exclusion criteria: (1) T4 stage tumors; (2) sphincter dysfunction before operation; (3) recurrent tumors; (4) lower edge of tumors beyond the dentate line; (5) death due to non-rectal cancer during follow-up and unsatisfactory follow-up data. The clinical data of 21 patients with low rectal cancer meeting inclusion criteria undergoing robotic-assisted ISR at our department from January 2015 to June 2018 were collected. Parameters during and after operation were observed. Anorectal manometry was performed at 3, 6, and 12 months after the operation, and anal function was evaluated at 3, 6, and 12 months after the closure of the stoma by Kirwan classification and Wexner fecal incontinence score. The key steps of the operation are as follows: according to the principle of total mesorectal excision, the robot continued to enter into the levator ani hiatusdistally, and dissectin the sphincter space; according to the scope of sphincter resection, ISRwas divided into partial ISR, subtotal ISR, and total ISR; subtotal and total ISR usually needed to be combined with transanal pathway. The reconstruction of digestive tract was performed by double stapler anastomosis under laparoscope orhand-sewnanastomosis under direct vision, and preventive ileostomy was completed in the right lower abdomen. Results: Of 21 patients, 13 were male and 8 were female with mean age of (57.5±16.3) years. All the patients successfully completed the operation without conversion to laparotomy. Fourteen cases (66.7%) adopted partial ISR through complete transabdominal approach, 6 cases (28.6%) adopted the subtotal ISR through combined transabdominal and transanal approachs, and 1 case (4.8%) adopted the total ISR through the combined transabdominal and transanal approachs. The total operation time was (213.1±56.3) minutes, including (27.3±5.4) minutes for mechanical arm installation and (175.7±51.6) minutes for robotic operation. The amount of intraoperative hemorrhage was (62.8±23.2) ml, and no blood transfusion was performed in any patient. All patients underwent prophylactic ileostomy, and the stoma was closed 3-6 months after the operation. Except one case of anastomotic leakage, all other stomas were closed successfully. The postoperative hospitalization time was (7.6±2.2) days, and time to fluid intake was (3.3±0.9) days. One case of anastomotic leakage, one case of anastomotic stenosis, one case of inflammatory external hemorrhoids and one case of urinary retention occurred after surgery,and all of them were cured by conservative treatment. The mean diameter of tumors was (2.9±1.2) cm, and the number of harvested lymph node was 12.8 ± 3.3. In the whole group, the circumcision margin was negative, the proximal margin was (12.2 ± 2.1) cm, the distal margin was (1.1 ± 0.4) with all negative, and the R0 resection rate was 100%. The results of anorectal manometry showed that the preoperative rest pressure, rectal maximum squeeze pressure, initial sensory volume and maximum tolerated volume were (45.19±8.46) mmHg, (128.18±18.80) mmHg, (44.33±10.11) ml and (119.00±19.28) ml, respectively;these parameters reduced significantly 3 months after operation and they were (23.44±5.54) mmHg, (93.72±12.15) mmHg, (17.72±5.32) ml and (70.44±10.9) ml, respectively. The differences were statistically significant (all P<0.001). The resting pressure and the rectal maximum squeeze pressure returned to preoperative levels 12 months after operation, which were (39.33±6.64) mmHg and (120.58±16.47) mmHg, respectively (both P>0.05), while the initial sensory volume and the maximum tolerated volume failed to reach the preoperative state, which were (30.67±7.45) ml and (92.25±10.32) ml, respectively (both P<0.05). The patients were followed up for (22.1±10.6) months without local recurrence and distant metastasis. Eighteen patients were evaluated for anal function: Kirwan classification was grade I for 6 cases, grade II for 7 cases, grade III for 4 cases, and grade IV for 1 case; Wexner incontinence score was 8.6±0.8; 14 cases had good defecation control. Conclusion: The clinical efficacy of ISR with Da Vinci robot in the treatment of low rectal cancer is satisfactory.

[Comparison of clinical efficacy between proximal gastrectomy with double tract reconstruction and total gastrectomy with Roux-en-Y reconstruction for proximal gastric cancer]

Objective: To compare the clinical efficacy of proximal gastrectomy with double tract reconstruction (PG-DT) and total gastrectomy with Roux-en-Y reconstruction (TG-RY) for proximal gastric cancer. Methods: The retrospective study was conducted. Clinicopathological data of 132 patients with proximal gastric cancer confirmed by pathology who underwent PG-DT (n=51) or TG-RY (n=81) by the same surgeon team in Southwest Hospital of Army Military Medical University between January 2006 and December 2016 were collected. Patients with preoperative neoadjuvant therapy, non-R0 resection and non-adenocarcinoma confirmed by pathology were excluded. Observation indicators included intraoperative (operation time and blood loss); postoperative (time to flatus, hospital stay, total complications, metastasis of lymph nodes around distal side of stomach from cases undergoing TG-RY), follow-up (long-term hemoglobin level, incidence of anemia, and survival) parameters. Survival analysis was conducted using the Kaplan-Meier method, and Log-rank test was used to compare survival difference between two groups. Results: No statistically significant differences were found between two groups in the baseline data, including age, gender, BMI, hemoglobin level before operation, postoperative TNM stage, tumor size and histological differentiation between two groups (all P>0.05). There were no significant differences between PG-DT and TG-RY in intraoperative blood loss [200 (200) ml vs. 200 (195) ml, Z=-1.860, P=0.063], time to flatus [(2.7±1.0) days vs. (2.6±1.1) days, t=0.225, P=0.823], postoperative hospital stay [10(3) days vs. 10 (4) days, Z=-0.449, P=0.654] and morbidity of perioperative complications [5.9% (3/51) vs. 8.6% (7/81), χ(2)=0.081, P=0.775]. Compared with the TG-RY group, PG-DT group had longer total operative time [294 (97) minutes vs. 255 (71) minutes, Z=-3.148, P=0.002]. The hemoglobin data of 42 patients with PG-DT and 56 patients with TG-RY were collected 1 year after operation. The incidence of anemia in PG-DT group was lower than that of TG-RY group [64.2%(27/42) vs. 82.1% (46/56), χ(2)=4.072, P=0.045], and PG-DT group had higher level of hemoglobin than TG-RY group [(114.4±16.3) g/L vs. (106.6±15.0) g/L, t=2.435, P=0.017]. There were 4 cases (4/81, 4.9%) with metastasis of lymph nodes around distal side of stomach in TG-RY group. All of these 4 tumors were T4 in depth and were more than 5 cm in diameter. The median follow-up period was 26 (1 to 110) months. One-year, 3-year and 5-year survival rates were 93.2%, 65.3% and 55.0% in PG-DT group, and 85.8%, 63.8% and 47.2% in TG-RY group, respectively without significant difference (χ(2)=0.890, P=0.345). Conclusions: Compared with TG-RY, PG-DT has the same safety and feasibility for proximal gastric cancer. Although the operative time is a little longer than TG-RY, PG-DT has advantages in improving the postoperative hemoglobin level.

MTMR2 promotes invasion and metastasis of gastric cancer via inactivating IFNγ/STAT1 signaling

Background

The aberrant expression of myotubularin-related protein 2 (MTMR2) has been found in some cancers, but little is known about the roles and clinical relevance. The present study aimed to investigate the roles and clinical relevance of MTMR2 as well as the underlying mechanisms in gastric cancer (GC).

Methods

MTMR2 expression was examined in 295 GC samples by using immunohistochemistry (IHC). The correlation between MTMR2 expression and clinicopathological features and outcomes of the patients was analyzed. The roles of MTMR2 in regulating the invasive and metastatic capabilities of GC cells were observed using gain-and loss-of-function assays both in vitro and in vivo. The pathways involved in MTMR2-regulating invasion and metastasis were selected and identified by using mRNA expression profiling. Functions and underlying mechanisms of MTMR2-mediated invasion and metastasis were further investigated in a series of in vitro studies.

Results

MTMR2 was highly expressed in human GC tissues compared to adjacent normal tissues and its expression levels were significantly correlated with depth of invasion, lymph node metastasis, and TNM stage. Patients with MTMR2^high had significantly shorter lifespan than those with MTMR2^low. Cox regression analysis showed that MTMR2 was an independent prognostic indicator for GC patients. Knockdown of MTMR2 significantly reduced migratory and invasive capabilities in vitro and metastases in vivo in GC cells, while overexpressing MTMR2 achieved the opposite results. MTMR2 knockdown and overexpression markedly inhibited and promoted the epithelial-mesenchymal transition (EMT), respectively. MTMR2 mediated EMT through the IFNγ/STAT1/IRF1 pathway to promote GC invasion and metastasis. Phosphorylation of STAT1 and IRF1 was increased by MTMR2 knockdown and decreased by MTMR2 overexpression accompanying with ZEB1 down-regulation and up-regulation, respectively. Silencing IRF1 upregulated ZEB1, which induced EMT and consequently enhanced invasion and metastasis in GC cells.

Conclusions

Our findings suggest that MTMR2 is an important promoter in GC invasion and metastasis by inactivating IFNγ/STAT1 signaling and may act as a new prognostic indicator and a potential therapeutic target for GC.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1186-z) contains supplementary material, which is available to authorized users.

Superiority of Tumor Location-Modified Lauren Classification System for Gastric Cancer: A Multi-Institutional Validation Analysis

Background

The tumor location-modified Lauren classification (mLC) has been proposed recently, but its clinical significance remains under debate. This study aimed to elucidate the clinical relevance of mLC and evaluate its superiority to the Lauren classification (LC) for gastric cancer patients with gastrectomy.

Methods

This study retrospectively evaluated 2764 consecutive gastric cancer patients from three comprehensive medical institutions. The patients were categorized into training, inner-validation, and independent validation sets. The relationships between mLC and other clinicopathologic factors were analyzed, and independent prognostic factors were identified. Survival prognostic discriminatory ability and predictive accuracy were compared between mLC and LC using the concordance index (C-index) and Akaike’s information criterion (AIC), and a nomogram based on mLC was constructed to compare its prognostic improvement with the tumor-node metastasis (TNM) staging system.

Results

A significant association between mLC and gender, age, histologic type, T stage, N stage, and M stage was found. The findings showed that mLC, not LC, is an independent prognostic factor, with a smaller AIC and a higher C-index than LC. The nomogram based on mLC showed a better predictive ability than TNM alone.

Conclusions

Compared with LC, mLC, which could be considered a more reliable prognostic factor, may improve the prognostic discriminatory ability and predictive accuracy for gastric cancer patients with gastrectomy.

Electronic supplementary material

The online version of this article (10.1245/s10434-018-6654-8) contains supplementary material, which is available to authorized users.

Overexpression of Tie2 is associated with poor prognosis in patients with gastric cancer

Tunica Interna endothelial cell kinase (Tie2)-expressing macrophages (TEMs) are a subgroup of tumor-associated macrophages that are associated with a poor prognosis in numerous types of cancer. The present study aimed to assess the prognostic impact of Tie2 expression in gastric cancer tissues. Between January 2009 and December 2009, 76 newly diagnosed patients with gastric cancer at the Southwest Hospital, Third Military Medical University (Chongqing, China) were enrolled. TEMs were detected using immunohistochemistry. Tie2, cluster of differentiation (CD)68 and carbonic anhydrase IX (CAIX) were analyzed using immunohistochemistry and immunofluorescent microscopy. Tie2 protein expression was analyzed using western blot analysis in hypoxic and normoxic gastric cancer tissues. The number of TEMs positively staining for Tie2 increased with the tumor-node-metastasis (TNM) stage: 0, 53.9, 75.6 and 100% in stages I, II, III and IV, respectively (P<0.001). Tumor size and lymph node involvement were significantly associated with the presence of Tie2 in the tumor stroma (P<0.001). There was no significant difference between Tie2 and CAIX, irrespective of how the patients were grouped (tumor size, lymph node involvement, TNM stage or histological grade). Tie2 protein expression was increased in the hypoxic regions of gastric tumors.Tie2 and CD68 expression colocalized in hypoxic and normoxic gastric cancer tissues. The 1-, 2- and 3-year recurrence rates of the TEM-positive group were 31.4, 56.9 and 66.7%, respectively, as compared with 8, 28 and 48%, respectively, for the TEM-negative group (P<0.05). In the TEM-negative group, 2 patients succumbed to the disease, as compared with 21 patients in the TEM-positive group (P<0.05). Therefore, high quantities of TEMs, represented by Tie2 expression, in gastric tumors may be associated with poor survival.

High density of CD68+ tumor-associated macrophages predicts a poor prognosis in gastric cancer mediated by IL-6 expression

The aim of the present study was to explore the potential role of cluster of differentiation CD68+ tumor-associated macrophages (TAMs) induced by interleukin (IL)-6 in the progression of gastric cancer (GC) and patient prognosis. The expression levels of IL-6 and CD68 were detected by immunohistochemical staining in 60 samples of tumor and non-tumor gastric tissues. CD14+ monocytes were isolated from peripheral blood mononuclear cells and stimulated with macrophage colony stimulation factor (M-CSF) and IL-6, and the expression levels of IL-10, IL-12, vascular endothelial growth factor (VEGF)-C and transforming growth factor (TGF)-β were measured by reverse transcription polymerase chain reaction and ELISA. The GC MGC-803 cell line was co-cultured with monocytes stimulated by M-CSF and IL-6 and the invasion ability of the MGC-803 was evaluated by Transwell analysis. The levels of STAT3, P-STAT3 and interferon-regulatory factor 4 (IRF4) in the monocytes stimulated by M-CSF and IL-6 were detected by western blotting. The results demonstrated that the frequencies of IL-6+ macrophages (Mφs) and CD68+ Mφs were significantly higher in tumor regions compared with the corresponding non-tumor regions of GC tissues. Kaplan-Meier analysis revealed that the densities of tumor-infiltrating CD68+ or IL-6+ Mφs were inversely associated with the overall survival rates of the patients. In vitro, the expression levels of IL-10, VEGF-C and TGF-β significantly increased in CD14+ monocytes subsequent to M-CSF and IL-6 stimulation. The invasion abilities of MGC-803 were increased by the monocytes stimulated with M-CSF and IL-6. The levels of STAT3, P-STAT3 and IRF4 proteins increased in the monocytes stimulated by M-CSF and IL-6. In conclusion, the results from the present study suggest that a high density of CD68+ TAMs predicts a poor prognosis in GC. IL-6 may polarize the Mφs and promote tumor invasion through the IL-6/STAT3/IRF4 signaling pathway.

HIF-1α induces the epithelial-mesenchymal transition in gastric cancer stem cells through the Snail pathway

Substantial evidence suggests that the epithelial-mesenchymal transition (EMT) phenotype is associated with the invasive characteristics of cancer stem cells (CSCs),which possess an EMT phenotype that may predominate in tumor invasion and metastasis. However, the mechanisms for the generation and regulation of these CSCs have not been clearly defined. As hypoxia and EMT-related factors may have important functions in EMT-like CSCs, the aim of this study was to investigate the effects of hypoxia on these cells. CSCs were established from the gastric cancer cell lines MGC-803 and SGC7901, and the relationship between hypoxia and EMT-like CSCs was investigated in gastric cancer. After hypoxia treatment, some gastric CSCs exhibited a marked increase in hypoxia-inducible factor-1α (HIF-1α)expression and increased migration and invasion capabilities compared with the normoxic control. These CSCs were defined by activation of the mesenchymal cell marker Vimentin and by inhibition of the epithelial cell marker E-cadherin. Our analyses also show that HIF-1α was responsible for activating EMT via increased expression of the transcription factor Snail in gastric CSCs. Moreover, inhibition of Snail by shRNA reduced HIF-1α-induced EMT in gastric CSCs. The results demonstrated that hypoxia-induced EMT-like CSCs rely on HIF-1αto activate Snail, which may result in recurrence and metastasis of gastric cancer.

ATG4A promotes tumor metastasis by inducing the epithelial-mesenchymal transition and stem-like properties in gastric cells

The metastasis of tumor cells to distant organs is an ominous feature of gastric cancer. However, the molecular mechanisms underlying the invasion and metastasis of gastric cancer cells remain elusive. In this study, we found that the expression of ATG4A, an autophagy-regulating molecule, was significantly increased in gastric cancer tissues and was significantlycorrelated with the gastric cancer differentiation degree, tumor invasion and lymph node metastasis. ATG4A over-expression significantly promoted gastric cancer cell migration and invasion in vitro and metastasis in vivo, as well as promoted gastric cancer cell stem-like properties and the epithelial-mesenchymal transition (EMT) phenotype. By contrast, ATG4A knockdown inhibited the migration, invasion and metastasis of cancer cells, as well as the stem-like properties and EMT phenotype. Mechanistically, ATG4A promotes gastric cancer cell stem-like properties and the EMT phenotype through the activation of Notch signaling not via autophagy, and using the Notch signaling inhibitor DAPT attenuated the effects of ATG4A on gastric cancer cells. Taken together, these findings demonstrated that ATG4A promotes the metastasis of gastric cancer cells via the Notch signaling pathway, which is an autophagy-independent mechanism.

Modulation of CD8+ memory stem T cell activity and glycogen synthase kinase 3β inhibition enhances anti-tumoral immunity in gastric cancer

The potential contributions of CD8⁺ memory stem T cells to anti-tumor immunity and immunotherapy responses in gastric cancer has not been demonstrated. We found that CD8⁺ memory stem T cell frequencies were increased in the peripheral blood of gastric cancer patients compared to healthy donors and declined in frequency with disease progression. Despite minimal in vitro cytotoxic activity, the adoptive transfer of CD8⁺ memory stem T cells into Rag1^-/- tumor bearing mice enhanced tumor regression compared to CD8⁺ central or effector memory T cell counterparts. This effect was associated with an increase in splenic, draining lymph node and tumor infiltrating CD8⁺ T cell numbers and the development of an altered CD8⁺ T cell phenotype not seen during homeostasis. GSK-3β inhibition is known to promote memory stem T cell accumulation by arresting effector T cell differentiation in vivo. Surprisingly however, GSK-3β inhibition conversely increased the cytotoxic capacity of CD8⁺ memory stem T cells in vitro, and this was associated with the induction of effector T cell-associated effector proteins including FasL. Finally, FasL neutralization following GSK-3β inhibition directly attenuated the anti-tumoral capacity of CD8⁺ memory stem T cells both in vitro and in vivo. Altogether, our findings identify the therapeutic potential of modulating CD8⁺ memory stem T cells for improved anti-tumoral responses against gastric cancer.

A retrospective, single-center cohort study on 65 patients with primary retroperitoneal liposarcoma

Primary retroperitoneal liposarcoma (PRPLS) is the most common soft tissue malignancy of the retroperitoneum. To determine the pathological features and the curative effects of surgery in patients with PRPLS, and to elucidate key prognostic factors, the present study retrospectively analyzed the clinical cases of 65 patients with PRPLS. Immunohistochemical analysis demonstrated that vimentin and Ki-67 are better indicators for PRPLS immunohistochemical diagnosis compared with S-100 protein. S-100 protein was predominantly expressed in well-differentiated PRPLS. Positive expression of vimentin and Ki-67 were observed in almost all PRPLS samples, and Ki-67 exhibited a higher expression level in high-grade PRPLS. The level of Ki-67 expression was negatively correlated with disease-specific survival (DSS). Survival analysis revealed that the pathological subtype and histological grade were associated with DSS and local recurrence in the patients, whereas the tumor burden was associated with DSS but not local recurrence. In addition, complete tumor resection and contiguous organ resection were able to improve DSS. Microscopically positive margins did not affect DSS, whereas gross margins did. Multivariate analysis revealed that pathological subtype, histological grade and contiguous organ resection were independent prognostic factors, and that histological grade was an independent factor for local recurrence. Patient sex and age at presentation were not independent factors associated with prognosis or local recurrence. Correlation analysis demonstrated that postoperative local recurrence significantly affected DSS, and local recurrence was the most common cause of mortality among patients. Histological grade was strongly associated with the invasion of adjacent organs but not with tumor burden. Furthermore, the tumor burden was not associated with recurrence or tumor invasion of adjacent organs. Ki-67 expression was associated with prognosis. Pathological subtype, histological grade and contiguous organ resection were independent prognostic factors, while histological grade was an independent factor which affected tumor recurrence.

Interleukin 6 induces M2 macrophage differentiation by STAT3 activation that correlates with gastric cancer progression

Interleukin 6 (IL-6) was abundant in the tumor microenvironment and played potential roles in tumor progression. In our study, the expression of IL-6 in tumor tissues from 36 gastric cancer (GC) patients was significantly higher than in non-tumor tissues. Moreover, the number of CD163+CD206+ M2 macrophages that infiltrated in tumor tissues was significantly greater than those infiltrated in non-tumor tissues. The frequencies of M2 macrophages were positively correlated with the IL-6 expression in GC tumors. We also found that IL-6 could induce normal macrophages to differentiate into M2 macrophages with higher IL-10 and TGF-β expression, and lower IL-12 expression, via activating STAT3 phosphorylation. Accordingly, knocking down STAT3 using small interfering RNA decreased the expression of M2 macrophages-related cytokines (IL-10 and TGF-β). Furthermore, supernatants from IL-6-induced M2 macrophages promote GC cell proliferation and migration. Moreover, IL-6 production and CD163+CD206+ M2 macrophage infiltration in tumors were associated with disease progression and reduced GC patient survival. In conclusion, our data indicate that IL-6 induces M2 macrophage differentiation (IL-10highTGF-βhighIL-12 p35low ) by activating STAT3 phosphorylation, and the IL-6-induced M2 macrophages exert a pro-tumor function by promoting GC cell proliferation and migration.

Robotic, laparoscopic and open surgery for gastric cancer compared on surgical, clinical and oncological outcomes: a multi-institutional chart review. A study protocol of the International study group on Minimally Invasive surgery for GASTRIc Cancer-IMIGASTRIC

INTRODUCTION

Gastric cancer represents a great challenge for healthcare providers and requires a multidisciplinary treatment approach in which surgery plays a major role. Minimally invasive surgery has been progressively developed, first with the advent of laparoscopy and recently with the spread of robotic surgery, but a number of issues are currently being debated, including the limitations in performing an effective extended lymph node dissection, the real advantages of robotic systems, the role of laparoscopy for Advanced Gastric Cancer, the reproducibility of a total intracorporeal technique and the oncological results achievable during long-term follow-up.

METHODS AND ANALYSIS

A multi-institutional international database will be established to evaluate the role of robotic, laparoscopic and open approaches in gastric cancer, comprising of information regarding surgical, clinical and oncological features. A chart review will be conducted to enter data of participants with gastric cancer, previously treated at the participating institutions. The database is the first of its kind, through an international electronic submission system and a HIPPA protected real time data repository from high volume gastric cancer centres.

ETHICS AND DISSEMINATION

This study is conducted in compliance with ethical principles originating from the Helsinki Declaration, within the guidelines of Good Clinical Practice and relevant laws/regulations. A multicentre study with a large number of patients will permit further investigation of the safety and efficacy as well as the long-term outcomes of robotic, laparoscopic and open approaches for the management of gastric cancer.

TRIAL REGISTRATION NUMBER

NCT02325453; Pre-results.

miR-203 suppression in gastric carcinoma promotes Slug-mediated cancer metastasis

MicroRNAs (miRNAs) play critical roles in tumorigenesis and cancer metastasis. Recently, miR-203 was reported as a tumor suppressor microRNA silenced in different malignancies including hepatocellular carcinoma, prostate cancer, oral cancer, breast cancer, and hematopoietic malignancy, whereas its role in the carcinogenesis of gastric carcinoma (GC) has not been evaluated. Here, we analyzed the levels of miR-203 and Slug in the GC specimen and studied their correlation. We analyzed the binding of miR-203 to the 3'-UTR of Slug messenger RNA (mRNA) and its effects on Slug translation by bioinformatics analysis and by luciferase-reporter assay, respectively. We modified miR-203 levels in GC cells and studied their effects on the cell invasiveness in transwell cell migration assay. We found that in GC, miR-203 levels were significantly decreased and Slug levels were significantly increased. miR-203 and Slug inversely correlated in patients' specimen. Bioinformatic analysis predicted that miR-203 may target the 3'-UTR of Slug mRNA to inhibit its translation, which was confirmed by luciferase-reporter assay. Overexpression of miR-203 inhibited Slug and cell invasiveness, while depletion of miR-203 increased Slug and cell invasiveness. These data suggest that miR-203 suppression in GC promotes Slug-mediated cancer metastasis.

Increased chemokine receptor IL-17RA expression is associated with poor survival in gastric cancer patients

BACKGROUND

Previous researchers have identified that the chemokine interleukin-17 (IL-17) was associated with survival time of patients with gastric cancer, but the roles of its receptors (IL-17R) in gastric cancer remain unknown. Our studies were designed to clarify the function of IL-17RA and to explore their potential role in gastric cancer.

MATERIALS AND METHODS

The expression of IL-17RA was determined in primary gastric cancer tissues (n=101) using Real-time RT-PCR, immunohistochemistry, and western blotting. To investigate the functional significance of IL-17RA expression, IL-17RA expression and clinical parameters, multivariate survival was analyzed in patients with gastric cancer.

RESULTS

IL-17RA was overexpression in gastric cancer tissues compared with adjacent normal tissues (P<0.05). The elevated expression level of IL-17RA was observed correlated significantly with tumor progression (P=0.003), Lymphatic invasion (P=0.019), lymphoid nodal status (P=0.001), distant metastasis (P<0.001) of gastric cancer patients, TNM stage (P=0.0013) and was one of the independent prognostic factors for patient's overall survival.

CONCLUSIONS

These results demonstrated that the expression of IL-17RA plays an important role in gastric cancer progression, migration and prognosis of gastric cancer. The IL-17-IL-17RA signaling mechanism may be a potential novel target.

Novel method for esophagojejunal anastomosis after laparoscopic total gastrectomy: Semi-end-to-end anastomosis

AIM: To test a new safe and simple technique for circular-stapled esophagojejunostomy in laparoscopic total gastrectomy (LATG).

METHODS: We selected 26 patients with gastric cancer who underwent LATG and Roux-en-Y gastrointestinal reconstruction with semi-end-to-end esophagojejunal anastomosis.

RESULTS: LATG with semi-end-to-end esophagojejunal anastomosis was successfully performed in all 26 patients. The average operation time was 257 ± 36 min, with an average anastomosis time of 51 ± 17 min and an average intraoperative blood loss of 88 ± 46 mL. The average postoperative hospital stay was 8 ± 3 d. There were no complications and no mortality in this series.

CONCLUSION: The application of semi-end-to-end esophagojejunal anastomosis after LATG is a safe and feasible procedure, which can be easily performed and has a short operation time in terms of anastomosis.

Chloride intracellular channel 1 regulates colon cancer cell migration and invasion through ROS/ERK pathway

AIM: To investigate the mechanisms of chloride intracellular channel 1 (CLIC1) in the metastasis of colon cancer under hypoxia-reoxygenation (H-R) conditions.

METHODS: Fluorescent probes were used to detect reactive oxygen species (ROS) in LOVO cells. Wound healing assay and transwell assay were performed to examine the migration and invasion of LOVO cells. Expression of CLIC1 mRNA and protein, p-ERK, MMP-2 and MMP-9 proteins was analyzed by reverse transcription-polymerase chain reaction and Western blot.

METHODS: H-R treatment increased the intracellular ROS level in LOVO cells. The mRNA and protein expression of CLIC1 was elevated under H-R conditions. Functional inhibition of CLIC1 markedly decreased the H-R-enhanced ROS generation, cell migration, invasion and phosphorylation of ERK in treated LOVO cells. Additionally, the expression of MMP-2 and MMP-9 could be regulated by CLIC1-mediated ROS/ERK pathway.

CONCLUSION: Our results suggest that CLIC1 protein is involved in the metastasis of colon cancer LOVO cells via regulating the ROS/ERK pathway in the H-R process.

Effects of Tiam 1 on invasive capacity of gastric cancer cells in vitro and underlying mechanisms

OBJECTIVE

To investigate changes in the invasive capacity of gastric cancer cells in vitro after expression inhibition of T lymphoma invasion and metastasis inducing factor 1 (Tiam 1) and underlying mechanisms.

METHODS

Using adhesion selection, two subpopulations with high (MH) or low (ML) invasive capacity were separated from the human gastric cancer cell line MKN-45 (M0). Tiam 1 antisense oligodeoxynucleotide (ASODN) was transfected into MH cells with liposomes, and expression of Tiam 1 mRNA and protein was determined by RT-PCR and quantitative cellular-ELISA. Changes in the cytoskeleton, invasive capacity in vitro and expression of ras-related C3 botulinum toxin substrate 1 (Rac 1), integrin β1 and matrix metalloproteinase 2 (MMP 2) between Tiam 1 ASODN transfected MH cells and non-transfected cells were observed by HE staining, cytoskeletal protein staining, scanning electron microscopy, Boyden chamber tests and cyto-immunohistochemistry.

RESULTS

A positive correlation existed between the expression level of Tiam l mRNA or protein and the invasion capacity of gastric cancer cells. After ASODN treatment (0.43 μM for 48 h), Tiam 1 mRNA transcription and protein expression in MH cells were decreased by 80% and 24% respectively (P < 0.05), compared with untreated controls, while invasive capacity in vitro was suppressed by 60% (P < 0.05). Morphologic and ultrastructural observation also showed that ASODN-treated MH cells exhibited smooth surfaces with obviously reduced filopodia and microspikes, which resembled M0 and ML cells. Additionally, cytoskeletal distribution dramatically altered from disorder to regularity with reduced long filament-like structure, projections, pseudopodia on cell surface, and with decreased acitn-bodies in cytoplasm. After Tiam 1 ASODN treatment, the expression of Rac 1 and Integrin β1 in MH cells was not affected (P > 0.05), but that of MMP 2 in MH cells was significantly inhibited compared with untreated cells (P < 0.05).

CONCLUSION

Over-expression of Tiam-1 contributes to the invasive phenotype of gastric cancer cells. Inhibition of Tiam 1 expression could impair the invasive capacity of gastric cancer cells through modulating reconstruction of the cytoskeleton and regulating expression of MMP 2.

Aberrant expression of Cx43 is associated with the peritoneal metastasis of gastric cancer and Cx43-mediated gap junction enhances gastric cancer cell diapedesis from peritoneal mesothelium

The process of peritoneal metastasis involves the diapedesis of intra-abdominal exfoliated gastric cancer cells through the mesothelial cell monolayers; however, the related molecular mechanisms for this process are still unclear. Heterocellular gap-junctional intercellular communication (GJIC) between gastric cancer cells and mesothelial cells may play an active role during diapedesis. In this study we detected the expression of connexin 43 (Cx43) in primary gastric cancer tissues, intra-abdominal exfoliated cancer cells, and matched metastatic peritoneal tissues. We found that the expression of Cx43 in primary gastric cancer tissues was significantly decreased; the intra-abdominal exfoliated cancer cells and matched metastatic peritoneal tissues exhibited increasing expression compared with primary gastric cancer tissues. BGC-823 and SGC-7901 human gastric cancer cells were engineered to express Cx43 or Cx43T154A (a mutant protein that only couples gap junctions but provides no intercellular communication) and were co-cultured with human peritoneal mesothelial cells (HPMCs). Heterocellular GJIC and diapedesis through HPMC monolayers on matrigel-coated coverslips were investigated. We found that BGC-823 and SGC-7901 gastric cancer cells expressing Cx43 formed functional heterocellular gap junctions with HPMC monolayers within one hour. A significant increase in diapedesis was observed in engineered Cx43-expressing cells compared with Cx43T154A and control group cells, which suggested that the observed upregulation of diapedesis in Cx43-expressing cells required heterocellular GJIC. Further study revealed that the gastric cancer cells transmigrated through the intercellular space between the mesothelial cells via a paracellular route. Our results suggest that the abnormal expression of Cx43 plays an essential role in peritoneal metastasis and that Cx43-mediated heterocellular GJIC between gastric cancer cells and mesothelial cells may be an important regulatory step during metastasis. Finally, we observed that the diapedesis of exfoliated gastric cancer cells through mesothelial barriers is a viable route of paracellular migration.

[Short-term efficacy of da Vinci robotic surgical system on rectal cancer in 101 patients]

OBJECTIVE

To investigate the feasibility and safety of da Vinci robotic surgical system in rectal cancer radical operation, and to summarize its short-term efficacy and clinical experience.

METHODS

Data of 101 cases undergoing da Vinci robotic surgical system for rectal cancer radical operation from March 2010 to September 2012 were retrospectively analyzed. Evaluation was focused on operative procedure, complication, recovery and pathology.

RESULTS

All the 101 cases underwent operation successfully and safely without conversion to open procedure. Rectal cancer radical operation with da Vinci robotic surgical system included 73 low anterior resections and 28 abdominoperineal resections. The average operative time was (210.3±47.2) min. The average blood lose was (60.5±28.7) ml without transfusion. Lymphadenectomy harvest was 17.3±5.4. Passage of first flatus was (2.7±0.7) d. Distal margin was (5.3±2.3) cm without residual cancer cells. The complication rate was 6.9%, including anastomotic leakage(n=2), perineum incision infection(n=2), pulmonary infection (n=2), urinary retention (n=1). There was no postoperative death. The mean follow-up time was(12.9±8.0) months. No local recurrence was found except 2 cases with distant metastasis.

CONCLUSION

Application of da Vinci robotic surgical system in rectal cancer radical operation is safe and patients recover quickly The short-term efficacy is satisfactory.

Autophagy protects against oxaliplatin-induced cell death via ER stress and ROS in Caco-2 cells

Oxaliplatin is included in a number of effective combination regimens used as first and subsequent lines of therapy for metastatic colorectal cancer. Accumulating evidence indicates that autophagy plays a significant role in response to cancer therapy. However, the role of autophagy in oxaliplatin-induced cell death remains to be clarified. In this study, we showed that oxaliplatin induced cell death and autophagy in Caco-2 colorectal cancer cells. The suppression of autophagy using either pharmacologic inhibitors (3-methyladenine, bafilomycin A1) or RNA interference in essential autophagy genes (ATG5 or Beclin1) enhanced the cell death and reactive oxygen species (ROS) production induced by oxaliplatin in Caco-2 cells. Blocking oxaliplatin-induced ROS production by using ROS scavengers (NAC or Tiron) decreased autophagy. Furthermore, numerous dilated endoplasmic reticula (ER) were present in oxaliplatin-treated Caco-2 cells, and blocking ER stress by RNA interference against candidate of metastasis-1 (P8) and C/EBP-homologous protein (CHOP) decreased autophagy and ROS production. Taken together, these data indicate that oxaliplatin activates autophagy as a cytoprotective response via ER stress and ROS in human colorectal cancer cells.

CD8(+) T cells that produce interleukin-17 regulate myeloid-derived suppressor cells and are associated with survival time of patients with gastric cancer

BACKGROUND & AIMS

CD8(+) T cells that produce interleukin (IL)-17 (Tc17 cells) promote inflammation and have been identified in tumors. We investigated their role in the pathogenesis of gastric cancer.

METHODS

We used flow cytometry analyses to determine levels and phenotype of Tc17 cells in blood and tumor samples from 103 patients with gastric cancer. We performed multivariate analysis to identify factors associated with overall survival using the Cox proportional hazards model. CD8(+) T cells and monocytes were isolated and cocultured in an assay for induction of Tc17 cells. Tumor cells and myeloid-derived suppressor cells (MDSCs) were isolated and used in assays of Tc17 cell function.

RESULTS

Tc17 cells with distinct cytokine and functional profiles were found in gastric tumor samples from patients. The percentage of Tc17 cells increased with tumor progression and was associated with overall survival time. Tumor-activated monocytes secreted IL-6, IL-1β, and IL-23, which promoted development of Tc17 cell populations. Supernatants from cultured Tc17 cells induced production of the chemokine CXCL12 by tumor cells; this promoted CXCR4-dependent migration of MDSCs and impaired functions of anti-tumor CD8(+) cytotoxic T cells via a cell contact-dependent mechanism.

CONCLUSIONS

Percentages of Tc17 cells in gastric tumors are associated with survival times of patients. These cells promote chemotaxis of MDSCs, which might promote tumor progression.

Regulation of colon cancer cell migration and invasion by CLIC1-mediated RVD

The metastasis of colorectal cancer is one of the most common causes of death in the world. In this investigation, we used the human colon cancer cell lines LOVO and HT29 as model systems to determine the role of the chloride intracellular channel 1 (CLIC1) in the metastasis of colonic cancer. In the present study, we found that regulatory volume decrease (RVD) capacity was markedly up-regulated in LOVO cells, which are characterized by a high metastatic potential. Functionally suppressing CLIC1 using the specific chloride intracellular channel 1 blocker Indanyloxyacetic acid 94 inhibited RVD and decreased the migration and invasion of colon cancer cells. Moreover, these effects occurred in a dose-dependent manner. The migration and invasion abilities in two cell lines also were inhibited by the knockdown of CLIC1 using small interfering RNA transfection. The mRNA and protein expression of CLIC1 is up-regulated in LOVO cells. In human colon cancer cells, CLIC1 is primarily located in the plasma membrane, where it functions as a chloride channel. Taken together, the results suggest that CLIC1 modulates the metastasis of colon cancer through its RVD-mediating chloride channel function. This study demonstrates, for the first time, that CLIC1 regulates the migration and invasion of colon cancer.

Increased miR-146a in gastric cancer directly targets SMAD4 and is involved in modulating cell proliferation and apoptosis

MicroRNAs (miRNAs) have emerged as important gene regulators and are recognized as oncogenes or tumor suppressor genes in carcinogenesis. Gastric cancer is one of the most common malignant diseases worldwide. Our previous studies have revealed that miR-146a is upregulated in gastric epithelial cells infected with Helicobacter pylori (H. pylori) and in mucosal tissues from H. pylori-positive patients. However, the role of miR-146a in gastric cancer is largely unknown. In the current study, we showed that miR-146a was upregulated in 20 gastric cancer tissues compared with matched non-tumor adjacent tissues by quantitative RT-PCR. Furthermore, ectopic expression of miR-146a could improve cell proliferation in vitro by using Cell Counting kit 8 (CCK-8). We also found that miR-146a inhibited apoptosis of gastric cancer cells by flow cytometry (FCM) and Caspase-Glo® 3/7 assay. Using target prediction algorithms, luciferase reporter assay and Western blot assay, SMAD family member 4 (SMAD4) was identified as a target gene of miR-146a in gastric cancer. Moreover, an inverse correlation was observed between the expression of SMAD4 mRNA and miR-146a in gastric cancer tissues (R=-0.731, P=0.039, Pearson's correlation). Taken together, our results provide important evidence that miR-146a can directly target SMAD4, and suggest that miR-146a may play a role in the development of gastric cancer by modulating cell proliferation and apoptosis. miR-146a could serve as a potential biomarker and therapeutic target against gastric cancer.

Laparoscopy-assisted resection for gastric stump cancer and gastric stump recurrent cancer: a report of 15 cases

OBJECTIVE

This study was designed to investigate the technical methods and clinical therapeutic effects of laparoscopy-assisted resection of gastric stump cancer (GSC).

METHODS

Laparoscopy-assisted resection was performed on 15 patients with GSC. The approach, method, difficult points, and techniques of the operation were analyzed, and its clinical therapeutic effect was evaluated.

RESULTS

With the help of laparoscopy, D2 radical resection of gastric stump was performed on 12 patients, and palliative gastric stump resection was performed on two patients. There was one case of conversion from laparoscopic surgery to open surgery. Roux-en-Y gastric bypass was performed in all cases to reconstruct the alimentary tract. The mean operative time for laparoscopy-assisted resection was 205 ± 25 min. The mean intraoperative blood loss volume was 110 ± 40 ml. The mean number of lymph nodes removed was 18 ± 5. A gastric tube was not placed in the patients after surgery. The mean time for the recovery of intestinal function was 2.5 ± 1 days, the mean duration of postoperative liquid diet was 2.5 ± 1 days, and the mean time for the recovery of ambulatory activity was 3 ± 0.5 days. There was one case of postoperative infection of the incision site. The follow-up time was 6-40 months, with 1 case of death due to liver metastasis, 1 case of death due to peritoneal metastasis, 1 case of death due to complications from lupus erythematosus, and survival for the remaining 12 cases.

CONCLUSIONS

Laparoscopy-assisted resection of GSC is technically feasible; determination of the short- and long-term efficacies will require a larger and comparative sample study.

Systemic and peritoneal inflammatory response after laparoscopic-assisted gastrectomy and the effect of inflammatory cytokines on adhesion of gastric cancer cells to peritoneal mesothelial cells

INTRODUCTION

There still remain concerns over the potential for peritoneal metastasis after laparoscopic surgery. We designed this trial to investigate the effects of the inflammatory cytokines interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) on the interaction between gastric cancer cells and mesothelial cells, and to evaluate differences in both the peritoneal and systemic cytokine (IL-1β and TNF-α) concentrations after laparoscopic and conventional surgical approaches, thus offering another possible advantage of laparoscopic procedures for treatment of gastric cancer.

EXPERIMENTAL DESIGN

A reproducible human in vitro assay was developed to study adhesion of SGC-7901 and MKN-45 human gastric cancer cells to monolayers of primary cultured human peritoneal mesothelial cells (HPMCs). Tumor cell adhesion to a mesothelial monolayer was assessed after preincubation of the monolayer with IL-1β and TNF-α using flow cytometry. Expression of adhesion molecules (ICAM-1, VCAM-1, and CD44) and their counterparts (LFA-1 and VLA-4) was investigated by real-time polymerase chain reaction (PCR) immunocytochemical staining. Furthermore, the proinflammatory cytokines IL-1β and TNF-α were measured perioperatively in peritoneal drain fluid and in serum by enzyme immunoassay.

RESULTS

Preincubation of the mesothelial monolayer with IL-1β and TNF-α resulted in enhanced tumor cell adhesion of SGC-7901 and MKN-45 cells. Mesothelial cells showed significant enhancement of expression of ICAM-1, VCAM-1, and CD44 after stimulation with IL-1β and TNF-α. Meanwhile their counterparts (LFA-1, VLA-4, and CD44) were identified in gastric cancer cells. The level of IL-1β in peritoneal drain fluid and in serum perioperatively in the laparoscopy-assisted gastrectomy group was lower than in the conventional open gastrectomy group, whereas there were no significant differences between the laparoscopic-assisted distal gastrectomy (LADG) and conventional open distal gastrectomy(CODG) groups with respect to TNF-α.

CONCLUSIONS

The presented results prove that IL-1β and TNF-α are significant stimulating factors in gastric cancer cell adhesion in vitro and may therefore partly account for local tumor recurrence and peritoneal metastasis in vivo. Owing to less impact on the postoperative abdominal regional and systemic immune responses, laparoscopic surgery not only shows clinically relevant advantages but also causes less effect of inflammatory factors on local recurrence and peritoneal metastasis of gastric cancer than conventional operations. Thus, we offer another possible advantage of laparoscopic procedures for treatment of gastric cancer.

[Effects of laparoscopy-assisted radical gastrectomy on the expression of intercellular adhesion molecule 1 and integrin beta(1) in peritoneal mesothelial cells and its significance]

OBJECTIVE

To investigate the changes of the expression of intercellular adhesion molecule-1 (ICAM-1) and integrin beta(1) in peritoneal mesothelial cells during laparoscopy-assisted radical gastrectomy(LARG) and to explore the possible effects of LARG on the peritoneal metastasis.

METHODS

From April to August 2008, LARG was performed for 26 patients with gastric cancer (laparoscopy group), while 20 cases underwent open radical gastrectomy(open group). Peritoneum of right upper belly was collected at 3 operation time points(the beginning, 2 hours, 4 hours). The expressions of ICAM-1 and integrin beta(1) in peritoneal mesothelial cells at 3 time points were detected by immunohistochemistry.

RESULTS

With the operation prolonging, the expression of ICAM-1 and integrin beta(1) was increased gradually in both LARG and open groups. The expression of integrin beta(1) in two groups was obviously increased at 4-hour time point as compared to the beginning(P<0.05). Besides, there were no significant differences of these two adhesion molecules among the three operation time points between two groups(P>0.05).

CONCLUSIONS

Compared with open surgery, LARG is not associated with a greater effect on the expression of ICAM-1 and integrin beta(1) in peritoneal mesothelial cells, and may not promote peritoneal metastasis of gastric cancer through increasing the expression of adhesion molecule in peritoneal mesothelial cells.

[Male sexual function after D(3) lymphadenectomy combined with pelvic autonomic nerve preservation by laparoscopic and open surgery for rectal cancer]

OBJECTIVE

To evaluate male sexual function in a series of rectal cancer patients randomized to laparoscopic(LS) or open surgery(OS).

METHODS

Between June 2006 and October 2007, a total of 119 patients with rectal cancer were randomly assigned to laparoscopic(n=60) or open (n=59) resection group. All the patients were treated by D(3) lymphadenectomy combined with pelvic autonomic nerve preservation(PANP) technique. Sexual function was assessed by International Index of Erectile Function(IIEF) before surgery and on 3, 6 and 12 months after operation.

RESULTS

Sexual dysfunction rate of LS and OS at 3rd month after operation were 23.3% and 32.3% respectively, and 18.3% vs 27.1% after 6 months, and 11.6% vs 16.9% after 12 months. There were no significant difference between LS and OS in sexual dysfunction rate after surgery.

CONCLUSIONS

Laparoscopic D(3) lymphadenectomy combined with PANP is not associated with higher sexual dysfunction rate, and the sexual function after laparoscopic surgery is satisfactory.

Evaluation of laparoscopic D3 radical correction with pelvic autonomic nerve preservation for rectal cancer

AIM: To evaluate the security and feasibility of laparoscopic D3 radical correction for rectal cancer.

METHODS: Sixty two cases diagnosed as rectal cancer in Duke's stage B or C from January 2007 to June 2008 at our hospital were arranged into two groups, of which, one group underwent open D3 radical correction and the other received laparoscopic D3 radical correction. At the same time, they all received pelvic autonomic nerve preservation.

RESULTS: The average operation time of laparoscopic group was 271 min, somewhat longer than that of open group, but the average hemorrhage volume was less. The detected lymph nodes for laparoscopic group and open group were 23.2 and 22.8, respectively, and no statistically significant difference was noted between them. In addition, no significant difference in short-term post-operative complications was observed between the two groups.

CONCLUSION: Laparoscopic radical correction with pelvic autonomic nerve preservation for rectal cancer has the same security and feasibility effects as open operation. So it is recommended for wide use in clinics.

Effects of HIF-1alpha on human gastric cancer cell apoptosis at different CO(2) pressures

The effects and potential molecular mechanisms underlying carbon dioxide (CO(2)) pneumoperitoneum on gastric cancer cell apoptosis are not fully understood. In this study, we assessed the effects of CO(2) pneumoperitoneum on the apoptosis of MKN-45 gastric cancer cells. Additionally, we investigated the role of HIF-1alpha in CO(2) pneumoperitoneum-induced apoptosis of gastric cancer cells. MKN-45 cells were cultured in CO(2) or air pneumoperitoneum at 0, 12 and 15 mmHg pressures for 4 h. We observed a change in cells morphology and increasing apoptotic ratios in MKN-45 cells when they were put into a 15 mmHg CO(2) pneumoperitoneum environment. However, there was no significant difference between the 0, 12 mmHg CO(2) pneumoperitoneum and the control groups. Exposure to 15 mmHg CO(2) pneumoperitoneum significantly enhanced the expression levels of HIF-1alpha and Bax, while it attenuated Bcl-2 expression levels. When we inhibited HIF-1alpha by small interfering RNA (siRNA), we found that the apoptotic ratio of MKN-45 cells decreased in 15 mmHg CO(2) pneumoperitoneum. This treatment markedly elevated Bcl-2 levels and decreased Bax expression. These data suggest that CO(2) pneumoperitoneum may accelerate the apoptosis of MKN-45 cells at higher pressures. HIF-1alpha is a crucial factor that affects gastric cancer cell apoptosis by downregulating the Bcl-2/Bax ratio.

[Changes of peritoneal free gastric cancer cells and its significance in patients after laparoscopic radical gastrectomy]

OBJECTIVE

To evaluate the safety and feasibility of laparoscopic radical gastrectomy on gastric cancer through comparison of peritoneal free gastric cancer cells detecting rates between laparoscopic and open radical gastrectomy.

METHODS

Sixty-three patients received laparoscopic gastrectomy and 61 patients received open gastrectomy between April 2006 and June 2008 were included in this study. The peritoneal lavage fluid in those patients before and after the operation was collected. The cancer cell cytology and carcinoembryonic antigen (CEA) mRNA were detected with those samples. The relationship between peritoneal free gastric cancer cells and the area of cancer-invaded serosa was also observed.

RESULTS

The positive rate of cytology in laparoscopic surgery was 25.4% in the peritoneal fluid after the operation, while it was 29.5% in the open surgery, there was no significant difference between the two groups (P > 0.05). The positive rate of CEA mRNA in the peritoneal fluid after the operation in the laparoscopic group was 41.3%, and was 40.3% in the open group (P > 0.05). The area of cancer-invaded serosa in patients with positive cytology before and after the operation in the laparoscopic group was (16.2 +/- 2.2) cm(2), and it was (17.6 +/- 3.0) cm(2) in their counterparts in the open surgery group, while it was (5.3 +/- 0.8) cm(2) in patients with negative cytology before and after the operation. The area of cancer-invaded serosa was positively correlated with the positive rate of cytology(R(2) = 0.874, P = 0.000).

CONCLUSIONS

Laparoscopic radical gastrectomy is not associated with a greater risk for peritoneal dissemination of cancer cells than the open technique.

Effects of simulated gravity loss on nuclear factor kappa-B expression in rat intestinal tissues

AIM: To investigate the effects of simulated gravity loss on NF-κB expression in rat intestinal tissues, and its significance.

METHODS: Tail-suspension (TS) was used to simulate the physiological effects of gravity loss. Eighty male Wistar rats were randomly assigned to 10 experimental groups suspended for 0.5, 1, 2, 7, 21 d respectively and their corresponding control groups. The dynamic expressions of NF-κB in intestinal tissues were seperately measured using the immunohistochemistry.

RESULTS: Compared with control groups, the expression levels of NF-κB in the intestinal tissue of tail-suspension 0.5, 1, 2, 7, 21 d groups were elevated significantly (10.11% ± 3.29% vs 5.50% ± 1.92%, 22.00% ± 5.31% vs 6.50% ± 2.32%, 25.50% ± 4.11% vs 8.75% ± 6.36%, 21.50% ± 3.02% vs 6.75% ± 2.12%, 10.87% ± 2.64% vs 5.62% ± 2.13%, all P < 0.01). NF-κB expression level began to rise in 0.5 tail-suspension group, and reached the maxium level in in 2 d group, then went down gradually.

CONCLUSION: The results suggest that simulated gravity loss acts as a kind of stress to elevate NF-κB expression and indicate a close link between altered intestinal NF-κB expression and tolerance of gravity loss.

Effects of simulated carbon dioxide and helium peumoperitoneum on proliferation and apoptosis of gastric cancer cells

AIM

To investigate the effects of carbon dioxide (CO(2)) and helium insufflation administered at different pressures on the growth and apoptosis of cultured human gastric cancer cells.

METHODS

The gastric cancer cells MKN-45 were exposed to a CO(2) and helium environment maintained at different pressures (0, 5, 10 and 15 mmHg). The cells were exposed to simulated pneumoperitoneum environment for 4 h, and pH of the culture media was measured after it was moved to normal conditions for 0, 2, 4, 6 and 8 h. Proliferation viability of MKN-45 was examined by 3-[4,5Dimethylthiazol-2-yl],5-diphenyltetrazolium bromide or triazolyl blue (MTT) assay after it was moved to normal conditions. Apoptotic ratio was measured by Annexin V-FITC/PI double labelled staining.

RESULTS

The pH of media was acid and recovered to normal after 4 h in the CO(2) group while it was basic in the helium group. There was no difference between CO(2) groups (under 10 mmHg ) and control group (P > 0.05) in the proliferative viability of the cells. The cultured cells exposed to 15 mmHg CO(2) environment grew more slowly than control group from 4 to 7 d (P < 0.01 ) while there was no difference from 1 to 3 d (P > 0.05). The proliferative viability in helium group was not obviously different from the control group (P > 0.05). The apoptotic ratio of the cultured cells was markedly higher than that of the control group (P < 0.01) at 10 and 15 mmHg CO(2) insufflation pressure. In helium group, the apoptotic ratio was not obviously different from the control group (P > 0.05).

CONCLUSION

There is no obvious effect in the proliferation and apoptosis of MKN-45 cells under 10 mmHg CO(2) insufflation pressure and helium in any pressure. Fifteen mmHg CO(2) insufflation pressure can inhibit the proliferation of the cells and improve apoptosis.

RNAi-mediated gene silencing of vascular endothelial growth factor inhibits growth of colorectal cancer

Vascular endothelial growth factor (VEGF) is overexpressed in colorectal cancer (CRCs) cells and plays a critical role in angiopoiesis and cell proliferation, making it a potential target for cancer therapy. We developed a system that blocks VEGF in the human colorectal cancer cell line, HCT116, using RNA interference. By transfecting CRCs with the small interfering RNA (siRNA) that targets human VEGF, we were able to establish a stable clones in which VEGF expression was significantly downregulated (p<0.01). This resulted in the decreased proliferation of HCT116 cells in vitro and suppressed the size of subcutaneous (s.c.) tumors and the microvessel density in an HCT116 s.c. nude mouse xenograft model in vivo (p<0.01). These results suggest that a strategy based on siRNA targeting of VEGF may build the foundation to the clinical management of CRC.

[Laparoscopic resection of gastric stromal tumors: report of 30 cases]

OBJECTIVE

To investigate the treatment efficacy of laparoscopic resection of gastric stromal tumors.

METHODS

The clinical data of 30 patients with laparoscopic resection of gastric stromal tumors from Apr. 2004 to Apr. 2006 were retrospectively analyzed.

RESULTS

The preoperative diagnosis of gastric stromal tumors mainly relied on gastroscope, ultrasound gastroscope, barium meal and abdominal CT scan. Tumor size ranged from 2 to 10 cm. Surgical procedures included laparoscopic wedge resection for 22 patients, laparoscopic distal gastrectomies for 6 patients, and laparoscopic proximal gastrectomies for 2 patients. All operations were successful, with an average operation time of 120+/-35 min and a blood loss of 5-200 ml. Postoperative length of stay was 4-10 days. No recurrence had occurred during 3-24 months follow-up.

CONCLUSION

Laparoscopic resection of gastric stromal tumors is a safe and reliable procedure, with quick postoperative recovery and minimal invasion.