ASCL2 induces an immune excluded microenvironment by activating cancer-associated fibroblasts in microsatellite stable colorectal cancer.

Proficient mismatch repair or microsatellite stable (pMMR/MSS) colorectal cancers (CRCs) are vastly outnumbered by deficient mismatch repair or microsatellite instability-high (dMMR/MSI-H) tumors and lack a response to immune checkpoint inhibitors (ICIs). In this study, we reported two distinct expression patterns of ASCL2 in pMMR/MSS and dMMR/MSI-H CRCs. ASCL2 is overexpressed in pMMR/MSS CRCs and maintains a stemness phenotype, accompanied by a lower density of tumor-infiltrating lymphocytes (TILs) than those in dMMR/MSI CRCs. In addition, coadministration of anti-PD-L1 antibodies facilitated T cell infiltration and provoked strong antitumor immunity and tumor regression in the MC38/shASCL2 mouse CRC model. Furthermore, overexpression of ASCL2 was associated with increased TGFB levels, which stimulate local Cancer-associated fibroblasts (CAFs) activation, inducing an immune-excluded microenvironment. Consistently, mice with deletion of Ascl2 specifically in the intestine (Villin-Cre+, Ascl2 flox/flox, named Ascl2 CKO) revealed fewer activated CAFs and higher proportions of infiltrating CD8+ T cells; We further intercrossed Ascl2 CKO with ApcMin/+ model suggesting that Ascl2-deficient expression in intestinal represented an immune infiltrating environment associated with a good prognosis. Together, our findings indicated ASCL2 induces an immune excluded microenvironment by activating CAFs through transcriptionally activating TGFB, and targeting ASCL2 combined with ICIs could present a therapeutic opportunity for MSS CRCs.

Survival outcomes following laparoscopic vs open surgery for non-metastatic rectal cancer: a two-center cohort study with propensity score matching.

BACKGROUND?>: Laparoscopic surgery for rectal cancer is commonly performed in China. However, compared with open surgery, the effectiveness of laparoscopic surgery, especially the long-term survival, has not been sufficiently proved. METHODS?>: Data of eligible patients with non-metastatic rectal cancer at Nanfang Hospital of Southern Medical University and Guangdong Provincial Hospital of Chinese Medicine between 2012 and 2014 were retrospectively reviewed. Long-term survival outcomes and short-term surgical safety were analysed with propensity score matching between groups. RESULTS: Of 430 cases collated from two institutes, 103 matched pairs were analysed after propensity score matching. The estimated blood loss during laparoscopic surgery was significantly less than that during open surgery (P = 0.019) and the operative time and hospital stay were shorter in the laparoscopic group (both P < 0.001). The post-operative complications rate was 9.7% in the laparoscopic group and 10.7% in the open group (P = 0.818). No significant difference was observed between the laparoscopic group and the open group in the 5-year overall survival rate (75.7% vs 80.6%, P = 0.346), 5-year relapse-free survival rate (74.8% vs 76.7%, P = 0.527), or 5-year cancer-specific survival rate (79.6% vs 87.4%, P = 0.219). An elevated carcinoembryonic antigen, <12 harvested lymph nodes, and perineural invasion were independent prognostic factors affecting overall survival and relapse-free survival. CONCLUSIONS?>: Our findings suggest that open surgery should still be the priority recommendation, but laparoscopic surgery is also an acceptable treatment for non-metastatic rectal cancer.

Initial Experience of Dual-Port Laparoscopic Distal Gastrectomy for Gastric Cancer: A Single-Arm Study.

INTRODUCTION: Dual-port laparoscopic gastrectomy (DPLG) has been widely performed in recent years for treating gastric cancers. The present study reports our initial experience of dual-port laparoscopic distal gastrectomy (DPLDG). METHODS: From November 2016 to August 2018, 38 consecutive patients underwent DPLDG in our center. The observational outcomes included 30-day morbidity and mortality rates, time to first flatus, time to first oral liquid diet, time to first oral semiliquid diet, time to drainage tube removal, visual analogue scale (VAS) score, postoperative 4-day recovery rate, additional analgesic use, hospital stay and cosmetic benefits. RESULTS: Mean operative time was 191.6 ± 44.4 min, mean intra-operative blood loss was 39.8 ± 48.7 ml, and the mean number of dissected lymph nodes was 38.3 ± 13.7 nodes. One case was converted to five-port laparoscopic surgery, and no intraoperative complications occurred in any of the cases. The mean time to postoperative first flatus was 45.3 ± 18.0 h. The mean time to intake of an oral liquid diet was 56.7 ± 30.4 h. The mean time to drainage tube removal was 97.9 ± 52.3 h. The mean VAS scores for the 3 days after surgery were 2.3 ± 0.7, 2.0 ± 0.6 and 1.6 ± 0.5, respectively. A total of 81.6% of the enrolled patients met the postoperative 4-day recovery standard, and 15.8% of patients received additional analgesics. The mean postoperative hospital stay was 6.0 ± 2.0 days. No deaths were observed, and the 30-day morbidity rate was 13.2%. CONCLUSION: DPLDG is a feasible and safe procedure for experienced surgeons with acceptable short-term outcomes, reduced invasiveness and good cosmetic effects.

Reduced Port Laparoscopic Distal Gastrectomy with D2 Lymphadenectomy.

BACKGROUND: Reduced port laparoscopic surgery (RPLS), as a more minimally invasive treatment alternative to conventional laparoscopic surgery (CLS), has been increasing in recent years. 1 With the accumulation of surgical experience and improvements in surgical techniques, the indication of RPLS has been gradually extended from benign diseases to malignant tumors, including gastric cancer. 2-4 However, due to the lack of counteraction and triangulation, lymphadenectomy during reduced port laparoscopic gastrectomy (RPLG) for gastric cancer was considered challenging. In this study, we report our experience performing RPLG with D2 lymphadenectomy for distal gastric cancer. METHODS: A disposable, single-incision, multiport, laparoscopic surgery trocar was used through a 3-cm incision at the umbilicus for the laparoscopist and surgeon's right hand. One 12-mm trocar was inserted at the upper-right quadrant for the surgeon's left hand. Distal gastrectomy with D2 lymphadenectomy was performed in the same manner with CLS. 5 After extracting the resected specimen through the umbilicus incision, intracorporeal Roux-en-Y or B-II gastrojejunostomy was used for reconstruction. RESULTS: RPLG with D2 lymphadenectomy was performed on five patients from April 2017 to June 2017. No intraoperative event requiring conversion to CLS or open surgery occurred. No postoperative complication was observed. The median operating time and blood loss was 166 min and 50 ml. The mean number of retrieved lymph nodes was 32.7. Postoperatively, the mean time to first flatus, soft intake, and hospital stay was 2.6, 3.5, and 6.7 days respectively. CONCLUSIONS: RPLG with D2 lymphadenectomy might be safe and feasible in selected patients.

Interleukin-17-Producing Neutrophils Link Inflammatory Stimuli to Disease Progression by Promoting Angiogenesis in Gastric Cancer.

Purpose: Elevated levels of neutrophils have been associated with poor survival in various cancers, but direct evidence supporting a role for neutrophils in the immunopathogenesis of human cancers is lacking.Experimental Design: A total of 573 patients with gastric cancer were enrolled in this study. Immunohistochemistry and real-time PCR were performed to analyze the distribution and clinical relevance of neutrophils in different microanatomic regions. The regulation and function of neutrophils were assessed both in vitro and in vivoResults: Increased neutrophil counts in the peripheral blood were associated with poor prognosis in gastric cancer patients. In gastric cancer tissues, neutrophils were enriched predominantly in the invasive margin, and neutrophil levels were a powerful predictor of poor survival in patients with gastric cancer. IL17+ neutrophils constitute a large portion of IL17-producing cells in human gastric cancer. Proinflammatory IL17 is a critical mediator of the recruitment of neutrophils into the invasive margin by CXC chemokines. Moreover, neutrophils at the invasive margin were a major source of matrix metalloproteinase-9, a secreted protein that stimulates proangiogenic activity in gastric cancer cells. Accordingly, high levels of infiltrated neutrophils at the invasive margin were positively correlated with angiogenesis progression in patients with gastric cancer.Conclusions: These data provide direct evidence supporting the pivotal role of neutrophils in gastric cancer progression and reveal a novel immune escape mechanism involving fine-tuned collaborative action between cancer cells and immune cells in the distinct tumor microenvironment. Clin Cancer Res; 23(6); 1575-85. ©2016 AACR.

Risk factors for pulmonary complications following laparoscopic gastrectomy: A single-center study.

The risk factors associated with postoperative pulmonary complications (PPCs) following laparoscopic gastrectomy have not been well studied. We sought to identify the risk factors for PPCs following gastric cancer surgery.A retrospective analysis was performed on all gastric cancer patients in a prospective database who underwent a laparoscopic gastrectomy from 2004 to 2014. The potential risk factors for PPCs were evaluated.PPCs occurred in 6.8% (83/1205) of patients and included pneumonia in 56 (67.5%) patients, pleural effusion in 26 (31.3%) patients, and pulmonary embolism in 1 (1.2%) patient. The multivariate analysis identified the following significant risk factors for PPCs: advanced age (odds ratio [OR] = 1.043, 95% confidence interval [CI] = 1.021%, 1.066%), chronic obstructive pulmonary disease (COPD) (OR = 17.788, 95% CI = 2.618%, 120.838%), total gastrectomy (OR = 2.781, 95% CI = 1.726%, 4.480%), time to first diet (OR = 1.175, 95% CI = 1.060%, 1.302%), and postoperative hospital stay (OR = 1.015, 95% CI = 1.002%, 1.028%). The risk factors for pneumonia included advanced age (OR = 1.036, 95% CI = 1.010%, 1.063%), total gastrectomy (OR = 3.420, 95% CI = 1.960%, 5.969%), and time to first diet (OR = 1.207, 95% CI = 1.703%, 1.358%). Only pancreatectomy was a risk factor for pleural effusion (OR = 9.082, 95% CI = 2.412%, 34.206%).The frequency of PPCs in patients with gastric cancer who underwent laparoscopic surgery was relatively high. Patients with cardiac and pulmonary comorbidities and those who undergo total gastrectomy and combined resection should be considered at high risk.

Staging laparoscopy improves treatment decision-making for advanced gastric cancer.

AIM: To evaluate the clinical value of staging laparoscopy in treatment decision-making for advanced gastric cancer (GC). METHODS: Clinical data of 582 patients with advanced GC were retrospectively analyzed. All patients underwent staging laparoscopy. The strength of agreement between computed tomography (CT) stage, endoscopic ultrasound (EUS) stage, laparoscopic stage, and final stage were determined by weighted Kappa statistic (Kw). The number of patients with treatment decision-changes was counted. A χ(2) test was used to analyze the correlation between peritoneal metastasis or positive cytology and clinical characteristics. RESULTS: Among the 582 patients, the distributions of pathological T classifications were T2/3 (153, 26.3%), T4a (262, 45.0%), and T4b (167, 28.7%). Treatment plans for 211 (36.3%) patients were changed after staging laparoscopy was performed. Two (10.5%) of 19 patients in M1 regained the opportunity for potential radical resection by staging laparoscopy. Unnecessary laparotomy was avoided in 71 (12.2%) patients. The strength of agreement between preoperative T stage and final T stage was in almost perfect agreement (Kw = 0.838; 95% confidence interval (CI): 0.803-0.872; P < 0.05) for staging laparoscopy; compared with CT and EUS, which was in fair agreement. The strength of agreement between preoperative M stage and final M stage was in almost perfect agreement (Kw = 0.990; 95% CI: 0.977-1.000; P < 0.05) for staging laparoscopy; compared with CT, which was in slight agreement. Multivariate analysis revealed that tumor size (≥ 40 mm), depth of tumor invasion (T4b), and Borrmann type (III or IV) were significantly correlated with either peritoneal metastasis or positive cytology. The best performance in diagnosing P-positive was obtained when two or three risk factors existed. CONCLUSION: Staging laparoscopy can improve treatment decision-making for advanced GC and decrease unnecessary exploratory laparotomy.

Evaluation of epithelial-mesenchymal transitioned circulating tumor cells in patients with resectable gastric cancer: Relevance to therapy response.

AIM: To evaluate the epithelial-to-mesenchymal transition (EMT) of circulating tumor cells (CTCs) in gastric cancer patients. METHODS: We detected tumor cells for expression of four epithelial (E(+)) transcripts (keratins 8, 18, and 19 and epithelial cell adhesion molecule) and two mesenchymal (M(+)) transcripts (Vimentin and Twist) by a quantifiable, dual-colorimetric RNA-in situ hybridization assay. Between July 2014 and October 2014, 44 patients with gastric cancer were recruited for CTC evaluation. Blood samples were obtained from selected patients during the treatment course [before surgery, after surgery and at the 6(th) cycle of XELOX based chemotherapy (about 6 mo postoperatively)]. RESULTS: We found the EMT phenomenon in which there were a few biphenotypic E(+)/M(+) cells in primary human gastric cancer specimens. Of the 44 patients, the presence of CTCs was reported in 35 (79.5%) patients at baseline. Five types of cells including from exclusively E(+) CTCs to intermediate CTCs and exclusively M(+) CTCs were identified (4 patients with M(+) CTCs and 10 patients with M(+) or M(+) > E(+) CTCs). Further, a chemotherapy patient having progressive disease showed a proportional increase of mesenchymal CTCs in the post-treatment blood specimens. We used NCI-N87 cells to analyze the linearity and sensitivity of CanPatrol(TM) system and the correlation coefficient (R(2)) was 0.999. CONCLUSION: The findings suggest that the EMT phenomenon was both in a few cells of primary tumors and abundantly in CTCs from the blood of gastric cancer patients, which might be used to monitor therapy response.

An automatically contamination-avoiding technique for intracorporeal esophagojejunostomy using a transorally inserted anvil during laparoscopic total gastrectomy for gastric cancer.

BACKGROUND: Intracorporeal Roux-en-Y esophagojejunostomy during laparoscopic total gastrectomy for gastric cancer remains a challenging manipulation due to the uncontrolled direction of the jejunal side or unintended embedded tissues, although several methods have been introduced. In this study, we simplified the procedure based on a surgical string fixing technique using a transorally inserted anvil (OrVil™; Covidien Ltd., Mansfield, MA, USA). METHODS: From March 2012 to September 2013, 14 consecutive patients underwent simplified intracorporeal Roux-en-Y esophagojejunostomy using OrVil™ during laparoscopic total gastrectomy for gastric cancer at our hospital. Clinicopathologic characteristics and surgical outcomes of these patients were retrospectively analyzed. RESULTS: All of the procedures were successful completed with no complication or conversion to open surgery. The mean overall operative time was 193.8 ± 41.8 min, whereas the mean reconstruction time was 32.6 ± 4.6 min. The mean estimated blood loss was 105.7 ± 65.4 ml. The mean diameter of anastomosis measured by upper gastrointestinal contrast X-ray test at 1 month after operation was 2.3 cm. During a median follow-up period of 12 months, neither local recurrence nor anastomosis-related morbidity was observed. CONCLUSIONS: Our preliminary results suggested that this automatically contamination-avoiding technique based on a surgical-string-fixing strategy using OrVil™ during laparoscopic total gastrectomy for gastric cancer might be feasible and safe and provide a simple solution for intracorporeal Roux-en-Y esophagojejunostomy.

Laparoscopic vs open D2 gastrectomy for locally advanced gastric cancer: a meta-analysis.

AIM: To conduct a meta-analysis comparing laparoscopic (LGD2) and open D2 gastrectomies (OGD2) for the treatment of advanced gastric cancer (AGC). METHODS: Randomized controlled trials (RCTs) and non-RCTs comparing LGD2 with OGD2 for AGC treatment, published between 1 January 2000 and 12 January 2013, were identified in the PubMed, Embase, and Cochrane Library databases. Primary endpoints included operative outcomes (operative time, intraoperative blood loss, and conversion rate), postoperative outcomes (postoperative analgesic consumption, time to first ambulation, time to first flatus, time to first oral intake, postoperative hospital stay length, postoperative morbidity, incidence of reoperation, and postoperative mortality), and oncologic outcomes (the number of lymph nodes harvested, tumor recurrence and metastasis, disease-free rates, and overall survival rates). The Cochrane Collaboration tools and the modified Newcastle-Ottawa scale were used to assess the quality and risk of bias of RCTs and non-RCTs in the study. Subgroup analyses were conducted to explore the incidence rate of various postoperative morbidities as well as recurrence and metastasis patterns. A Begg's test was used to evaluate the publication bias. RESULTS: One RCT and 13 non-RCTs totaling 2596 patients were included in the meta-analysis. LGD2 in comparison to OGD2 showed lower intraoperative blood loss [weighted mean difference (WMD) = -137.87 mL, 95%CI: -164.41--111.33; P < 0.01], lower analgesic consumption (WMD = -1.94, 95%CI: -2.50--1.38; P < 0.01), shorter times to first ambulation (WMD = -1.03 d, 95%CI: -1.90--0.16; P < 0.05), flatus (WMD = -0.98 d, 95%CI: -1.30--0.66; P < 0.01), and oral intake (WMD = -0.85 d, 95%CI: -1.67--0.03; P < 0.05), shorter hospitalization (WMD = -3.08 d, 95%CI: -4.38--1.78; P < 0.01), and lower postoperative morbidity (odds ratio = 0.78, 95%CI: 0.61-0.99; P < 0.05). No significant differences were observed between LGD2 and OGD2 for the following criteria: reoperation incidence, postoperative mortality, number of harvested lymph nodes, tumor recurrence/metastasis, or three- or five-year disease-free and overall survival rates. However, LGD2 had longer operative times (WMD = 57.06 min, 95%CI: 41.87-72.25; P < 0.01). CONCLUSION: Although a technically demanding and time-consuming procedure, LGD2 may be safe and effective, and offer some advantages over OGD2 for treatment of locally AGC.

[Quality control of laparoscopic surgery for gastric cancer].

As the improvement of technique and accumulation of experience in the past decade, the development of laparoscopic surgery has been in the advanced phase for the minimally invasive surgery for the management of gastric cancer. Even laparoscopic surgery has severaladvantages such as faster recovery courses and improved quality of life, however, surgical quality control for oncology must always be the most important consideration. The quality control system consists of accurate clinical staging, patient selection, intraoperative standard operating procedure, proper education and training course, data management for clinicopathologic information, and evidence-based studies.

Laparoscopic splenic hilum lymph node dissection for advanced proximal gastric cancer: a modified approach for pancreas- and spleen-preserving total gastrectomy.

AIM: To investigate the feasibility and optimal approach for laparoscopic pancreas- and spleen-preserving splenic hilum lymph node dissection in advanced proximal gastric cancer. METHODS: Between August 2009 and August 2012, 12 patients with advanced proximal gastric cancer treated in Nanfang Hospital, Southern Medical University, Guangzhou, China were enrolled and subsequently underwent laparoscopic total gastrectomy with pancreas- and spleen-preserving splenic hilum lymph node (LN) dissection. The clinicopathological characteristics, surgical outcomes, postoperative course and follow-up data of these patients were retrospectively collected and analyzed in the study. RESULTS: Based on our anatomical understanding of peripancreatic structures, we combined the characteristics of laparoscopic surgery and developed a modified approach (combined supra- and infra-pancreatic approaches) for laparoscopic pancreas- and spleen-preserving splenic hilum LN dissection. Surgery was completed in all 12 patients laparoscopically without conversion. Only one patient experienced intraoperative bleeding when dissecting LNs along the splenic artery and was handled with laparoscopic hemostasis. The mean operating time was 268.4 min and mean number of retrieved splenic hilum LNs was 4.8. One patient had splenic hilum LN metastasis (8.3%). Neither postoperative morbidity nor mortality was observed. Peritoneal metastasis occurred in one patient and none of the other patients died or experienced recurrent disease during the follow-up period. CONCLUSION: Laparoscopic total gastrectomy with pancreas- and spleen-preserving splenic hilum LN dissection using the modified approach for advanced proximal gastric cancer could be safely achieved.

[Risk factors associated with postoperative complications of D2 radical resection for local advanced gastric cancer].

OBJECTIVE: To evaluate the risk factors of postoperative complications following D2 radical resection for advanced gastric cancer. METHODS: From June 2004 to May 2011, 483 patients with local advanced gastric cancer who underwent radical gastrectomy with D2 lymph node dissection were enrolled in the study, including 132 patients of LAG (27.3%) and 351 patients of open procedure (72.7%). Clinicopathological data and postoperative complications were reviewed retrospectively. Postoperative complications were classified into overall and severe complications according to Clavien-Dindo Classification. Multivariate logistic model was used to identify risk factors of postoperative complications. RESULTS: The overall incidence of postoperative overall and severe complications and mortality were 12.4% (60/483), 2.5% (12/483) and 0.2% (1/483), respectively. Univariate analysis showed that no significant differences were found in overall and severe complications between the two surgical approaches (13.6% vs. 12.0%, P=0.620; 3.0% vs. 2.3%, P=0.743). Furthermore, multivariate analysis showed that age ≥60 years, preoperative comorbidity and intraoperative blood loss >300 ml were independent risk factors associated with overall postoperative complications. Remarkably, intraoperative blood loss >300 ml was also an independent risk factor for severe postoperative complications. CONCLUSIONS: LAG with D2 lymph node dissection for local advanced gastric cancer is technically feasible and safe. However, the elderly, preoperative comorbidity and increased intraoperative blood loss are associated with elevated risk of complications. Decreased intraoperative bleeding may reduce the potential postoperative complications.

[The safety and long-term survival after laparoscopic surgery versus open surgery for colon cancer].

OBJECTIVE: To evaluate the short-term outcomes and 5-year recurrence, overall survival, and disease-free survival of laparoscopic assisted surgery for colon cancer. METHODS: The clinical and pathologic data were compared between the patients who underwent colectomy during March 2003 to July 2008 and assigned in laparoscopic group (n = 92) and open group (n = 285) according the surgical approach. The 5-year overall survival, disease-free survival, and recurrence rate were analyzed for all patients who were followed-up for more than 36 months in either of the groups. RESULTS: The laparoscopic colectomy was associated with manifested less blood loss (50(50) ml) (Z = -8.292, P < 0.01), early return of bowel function (the evacuation time was (3.0 ± 1.0) days, and the meal time after operation was (4.0 ± 1.3) days) (t = -6.475 and -4.871, P < 0.01), and longer length (cm) of distal resection margin ((10 ± 4) cm vs. (9 ± 4) cm, t = 3.527, P = 0.000). The 5-year overall survival of the laparoscopic group and the open group were 63.6% and 61.8% respectively. The 5-year disease-free survival of the I-III stage patients in the laparoscopic group and the open group were 69.5% and 65.5% respectively, and the local recurrence were 8.7% and 13.6% (all P > 0.05). CONCLUSION: The laparoscopic colectomy for colon cancer is safe in short-term clinical results and non-inferior to the open colectomy in long-term oncological outcomes.