Comparison of Surgical and Oncological Outcomes of Laparoscopic and Open Gastrectomy for Pathologically Serosa-Invasive (pT4a) Advanced Gastric Cancer-Retrospective Propensity Score-Matched Analysis.

Background: We aimed to clarify the operative feasibility and oncological efficacy of a laparoscopic gastrectomy (LG) for pT4a gastric cancer through comparison with open gastrectomy (OG). Materials and Methods: We compared surgical and oncological outcomes in 178 patients with pT4a gastric cancer who underwent LG or OG between 2002 and 2016; the background was adjusted using propensity score matching. Results: After score matching, 45 patients were included in each group. The LG group had a significantly longer operation time (277 minutes versus 175 minutes, P < .001) and lower estimated blood loss (50 mL versus 280 mL, P < .001). The total number of dissected lymph nodes did not differ between groups (46 versus 38, P = .119); however, the number of dissected suprapancreatic lymph nodes was significantly higher in the LG group (11 versus 7.5, P = .011). Postoperative morbidity rates did not differ between groups. Postoperative hospitalization was significantly shorter in the LG group (7 days versus 13 days, P < .01), whereas overall survival, disease-free survival, and cancer recurrence rates and patterns were similar between groups. Conclusions: LG for pT4a gastric cancer has feasible and acceptable outcomes compared with OG.

Tumor free distance from serosa and survival rates of endometrial cancer patients: A meta-analysis.

Myometrial invasion and its extent have been directly associated with the risk of relapse as well as the overall survival of endometrial cancer patients. Tumor free distance from the serosal surface of the uterine wall has been investigated the last years by several studies, however, to date, its importance remains unknown. The present meta-analysis is based on a systematic search of the Medline, Scopus, Clinicaltrials.gov, EMBASE, Cochrane Central Register of Controlled Trials CENTRAL and Google Scholar databases and has been designed according to the PRISMA guidelines. Nine studies were included in the present systematic review that recruited pathology slides from 1,598 endometrial cancer patients and their meta-analysis indicated that TFD was significantly associated with the progression free survival of patients with endometrial cancer (OR 0.36, 95% CI 0.20, 0.65). The disease specific survival was not affected by the TFD (OR 0.30, 95% CI 0.09, 1.01). Sensitivity analyses revealed, however, that both the progression free and overall survival rates were associated with TFD. Significant discrepancies were observed in terms of histological subtypes and stage of the disease among included patients, hence, the actual importance of TFD in specific subgroups remains unknown. Future studies must evaluate the importance of this pathology marker particularly in patients with endometrioid subtypes and early-stage disease, as it is believed that in this group its importance will be more predictive as it will not be skewed by the presence of more important factors such as more aggressive histology and advanced stage disease.

Impact of Subclassification of Serosal Invasion on the Survival of Patients With T4a Gastric Cancer.

BACKGROUND/AIM: In the Japanese Classification of Gastric Carcinoma, T4a gastric cancer is defined as tumor invasion contiguous to the serosa or penetrating the serosa with exposure to the peritoneal cavity. The aim of this study was to assess the impact of T4a subclassification of gastric cancer on survival. PATIENTS AND METHODS: A total of 326 patients with T4a cancer who had undergone gastrectomy were enrolled. The T4a tumors were classified into two groups: serosa-contiguous or serosa-exposed. RESULTS: The serosa-exposed group had a significantly worse prognosis, and multivariate analysis identified the T4a subclass as an independent prognostic factor. Analysis of the risk factors for recurrence identified the T4a subclass as a significant risk factor for peritoneal recurrence in patients undergoing curative gastrectomy. CONCLUSION: The serosa-contiguous and serosa-exposed subgroups of T4a gastric cancer showed different biological behaviors. These groups may need to be treated as separate.

Prediction of the peritoneal recurrence via the macroscopic diagnosis of the serosal invasion in patients with gastric cancer: Supplementary analysis of JCOG0110.

BACKGROUND: Indications for adjuvant chemotherapy for advanced gastric cancer are determined based on the pathological diagnosis. However, macroscopic diagnoses have been reported as predictors of peritoneal recurrence and survival. This study investigated the predictability of peritoneal recurrence and survival based on macroscopically (sT) and pathologically (pT) diagnosed serosal invasion to identify more sensitive predictors of peritoneal recurrence. METHODS: This study included 396 patients who underwent R0 resection without adjuvant chemotherapy with S-1 in the JCOG0110 study. Tumor depth limited to the subserosa (SS) was defined as serosal invasion negative (T-), while tumors with serosal invasion (SE, SI) were defined as serosal invasion positive (T+). The predictability of peritoneal recurrence based on sT and pT was evaluated using the Fine and Gray model. Cox regression analyses were performed for overall survival (OS) and relapse-free survival (RFS) with sT or pT as covariates. FINDINGS: A total of 150 patients (37.9%) were sT+ and 82 (26.3%) were pT+. Sixty-two patients (15.7%) were sT+/pT+, 88 (22.2%) were sT+/pT-, 20 (5.1%) were sT-/pT+, and 226 (57.1%) were sT-/pT-. Both sT and pT were found to be independent predictors of peritoneal recurrence, OS, and RFS. The 5-year RFS rates of sT+/pT+, sT+/pT-, sT-/pT+, and sT-/pT-patients were 45.2%, 63.6%, 55.0%, and 81.8%, respectively. CONCLUSION: Intraoperatively diagnosed macroscopic serosal invasion showed a similar predictive value for peritoneal recurrence as pathologically diagnosed serosal invasion. The establishment of a novel staging system incorporating macroscopic serosal invasion is recommended.

Serous Membrane Detachment with Ultrasonic Homogenizer Improves Engraftment of Fetal Liver to Liver Surface in a Rat Model of Cirrhosis.

Liver transplantation is the most effective treatment for end-stage cirrhosis. However, due to serious donor shortages, new treatments to replace liver transplantation are sorely needed. Recent studies have focused on novel therapeutic methods using hepatocytes and induced pluripotent stem cells, we try hard to develop methods for transplanting these cells to the liver surface. In the present study, we evaluated several methods for their efficiency in the detachment of serous membrane covering the liver surface for transplantation to the liver surface. The liver surface of dipeptidyl peptidase IV (DPPIV)-deficient rats in a cirrhosis model was detached by various methods, and then fetal livers from DPPIV-positive rats were transplanted. We found that the engraftment rate and area as well as the liver function were improved in rats undergoing transplantation following serous membrane detachment with an ultrasonic homogenizer, which mimics the Cavitron Ultrasonic Surgical Aspirator® (CUSA), compared with no detachment. Furthermore, the bleeding amount was lower with the ultrasonic homogenizer method than with the needle and electric scalpel methods. These findings provide evidence that transplantation to the liver surface with serous membrane detachment using CUSA might contribute to the development of new treatments for cirrhosis using cells or tissues.

Eosinophilic Gastroenteritis: Using Presenting Findings to Predict Disease Course.

INTRODUCTION: Studies on eosinophilic gastroenteritis have identified broad spectrums of disease. We aimed to characterize subtypes of disease and ascertain outcomes of each group. METHODS: This is a retrospective cohort study from a large tertiary medical center including 35 patients diagnosed with eosinophilic gastroenteritis from 2007 to 2018. We defined 2 groups of patients based on clinical and laboratory findings at presentation. Severe disease was defined as having weight loss at time of presentation, hypoalbuminemia at presentation, serosal disease involvement, or anemia at diagnosis. The remaining patients were labeled as mild disease group. We collected and compared demographic data, clinical features, laboratory findings, an allergy history, and disease course of both cohorts. RESULTS: Among 35 patients with eosinophilic gastroenteritis, 18 patients met the criteria for severe disease and 17 patients for mild disease. Of the patients with severe eosinophilic gastroenteritis, 6 (38%) had remission without chronic symptoms, whereas 10 (63%) had chronic symptoms requiring chronic medical therapy. Of the mild group, 12 patients (80%) had disease remission without chronic medications. An allergy history was more common in the severe disease group (83%) compared with the mild disease group (45%). Prednisone and open capsule budesonide were the most commonly used treatment medications in both groups. DISCUSSION: Patients with eosinophilic gastroenteritis may be characterized into 2 forms. Patients with weight loss at time of presentation, hypoalbuminemia at presentation, serosal disease involvement, or anemia at diagnosis were associated with a chronic disease course requiring chronic medications.

The prognostic impact of macroscopic serosal change on resectable advanced gastric cancer.

BACKGROUND: Advanced gastric cancer sometimes causes macroscopic serosal change (MSC) due to direct invasion or inflammation. However, the prognostic significance of MSC remains unclear. METHODS: A total of 1410 patients who had been diagnosed with deeper-than-pathological-T2 gastric cancer and undergone R0 gastrectomy with lymph node dissection at the National Cancer Center Hospital during January 2000 and December 2012 were restrospectively reviewed. RESULTS: MSC was not found in 108 of the 506 patients with pathological T4a (21.3%), whereas it was detected in 250 of the 904 patients with pathological T2-T3 (27.7%). The sensitivity, specificity and accuracy for diagnosing pathological serosa exposed (SE) by MSC were 78.7, 72.3 and 74.6%, respectively. The MSC-positive cases had a worse 5-year overall survival (OS) than the MSC-negative cases in pT3 (72.9% vs. 84.3%, p = 0.001), pT4a (56.2% vs. 73.4%, p = 0.001), pStageIIB (76.0% vs. 88.4%, p = 0.005), pStageIIIA (63.4% vs. 75.6%, p = 0.019), pStageIIIB (53.6% vs. 69.2%, p = 0.029) and pStage IIIC (27.6% vs. 50.0%, p = 0.062). A multivariate analysis showed that MSC was a significant independent predictor for the OS (hazard ratio [HR]: 1.587, 95%CI 1.209-2.083, p = 0.001) along with the tumor depth (HR: 7.742, 95%CI: 2.935-20.421, p < 0.001), nodal status (HR:5.783, 95% CI 3.985-8.391, p < 0.001) and age (HR:2.382, 95%CI: 1.918-2.957, p < 0.001). Peritoneal recurrence rates were higher in the MSC-positive cases than in the MSC-negative cases at each pT stage. CONCLUSIONS: In this study, the MSC was one of the independent prognostic factors in patients with resectable locally advanced gastric cancer.

Prediction of serosal invasion in gastric cancer: development and validation of multivariate models integrating preoperative clinicopathological features and radiographic findings based on late arterial phase CT images.

BACKGROUND: To develop and validate multivariate models integrating endoscopic biopsy, tumor markers, and CT findings based on late arterial phase (LAP) to predict serosal invasion in gastric cancer (GC). METHODS: The preoperative differentiation degree, tumor markers, CT morphological characteristics, and CT value-related and texture parameters of 154 patients with GC were analyzed retrospectively. Multivariate models based on regression analysis and machine learning algorithms were performed to improve the diagnostic efficacy. RESULTS: The differentiation degree, carbohydrate antigen (CA) 199, CA724, CA242, and multiple CT findings based on LAP differed significantly between T1-3 and T4 GCs in the primary cohort (all P < 0.05). Multivariate models based on regression analysis and random forest achieved AUCs of 0.849 and 0.865 in the primary cohort, respectively. CONCLUSION: We developed and validated multivariate models integrating endoscopic biopsy, tumor markers, CT morphological characteristics, and CT value-related and texture parameters to predict serosal invasion in GCs and achieved favorable performance.

The concept of mesothelioma in situ, with consideration of its potential impact on cytology diagnosis.

Diffuse malignant mesothelioma (MM) is an incurable tumour of the serosal membranes, which is often caused by exposure to asbestos and commonly diagnosed at advanced stage. Malignant mesothelioma in situ (MMIS) is now included as diagnostic category by the World Health Organization (WHO). However, our international survey of 34 pulmonary pathologists with an interest in MM diagnosis highlights inconsistency regarding how the diagnosis is being made by experts, despite published guidelines. Whilst the WHO restricts the diagnosis to surgical samples, the very concept has implication for cytological diagnosis, which is already regarded as controversial in itself by some. MMIS is currently only applicable as precursor to MM with an epithelioid component, and raises the possibility for different molecular pathways for different histological MM subtypes. The clinical implications of MMIS at this stage are uncertain, but aggressive therapies are being initiated in some instances. Based on the results of the survey we here present a critical appraisal of the concept, its clinical and conceptual implications and provide practice suggestions for diagnosis. A low threshold for ancillary testing is suggested. The designations of 'malignant mesothelioma, cannot exclude MMIS' or 'atypical mesothelial proliferation with molecular indicators of malignancy, so-called MMIS' could be used on cytology samples, adding 'no evidence of invasion in sample provided' for surgical samples. Clinical and radiological correlation are integral to diagnosis and best done at multidisciplinary meetings. Finally, collaborative studies are required to improve our understanding of MMIS.

PAR-2-activated secretion by airway gland serous cells: role for CFTR and inhibition by Pseudomonas aeruginosa.

Airway submucosal gland serous cells are important sites of fluid secretion in conducting airways. Serous cells also express the cystic fibrosis (CF) transmembrane conductance regulator (CFTR). Protease-activated receptor 2 (PAR-2) is a G protein-coupled receptor that activates secretion from intact airway glands. We tested if and how human nasal serous cells secrete fluid in response to PAR-2 stimulation using Ca2+ imaging and simultaneous differential interference contrast imaging to track isosmotic cell shrinking and swelling reflecting activation of solute efflux and influx pathways, respectively. During stimulation of PAR-2, serous cells exhibited dose-dependent increases in intracellular Ca2+. At stimulation levels >EC50 for Ca2+, serous cells simultaneously shrank ∼20% over ∼90 s due to KCl efflux reflecting Ca2+-activated Cl- channel (CaCC, likely TMEM16A)-dependent secretion. At lower levels of PAR-2 stimulation (

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.

Predicting postoperative peritoneal metastasis in gastric cancer with serosal invasion using a collagen nomogram.

Accurate prediction of peritoneal metastasis for gastric cancer (GC) with serosal invasion is crucial in clinic. The presence of collagen in the tumour microenvironment affects the metastasis of cancer cells. Herein, we propose a collagen signature, which is composed of multiple collagen features in the tumour microenvironment of the serosa derived from multiphoton imaging, to describe the extent of collagen alterations. We find that a high collagen signature is significantly associated with a high risk of peritoneal metastasis (P < 0.001). A competing-risk nomogram including the collagen signature, tumour size, tumour differentiation status and lymph node metastasis is constructed. The nomogram demonstrates satisfactory discrimination and calibration. Thus, the collagen signature in the tumour microenvironment of the gastric serosa is associated with peritoneal metastasis in GC with serosal invasion, and the nomogram can be conveniently used to individually predict the risk of peritoneal metastasis in GC with serosal invasion after radical surgery.

Adenomatoid Tumor of the Uterus: A Report of 6 Unusual Cases With Prominent Cysts Including 4 With Diffuse Myometrial Involvement, 4 With Uterine Serosal Involvement, and 2 Presenting in Curettage Specimens.

We evaluated the clinicopathologic features of 6 adenomatoid tumors of the uterus with unusual features. All the tumors differed grossly from the usual adenomatoid tumor, typically being ill-defined and occupying >50% of the myometrium, essentially replacing it in 4. The neoplasm extended to the endometrium in 2 cases and in one of these it formed an intracavitary mass; in both the tumor was first diagnosed in a curettage. In the other 4 cases, the adenomatoid tumor was discovered in a hysterectomy specimen performed for irregular vaginal bleeding (3 patients), and the finding of a pelvic mass on a computed tomography scan in a patient with right lower quadrant pain. The tumors extended to the uterine serosa in the form of small grape-like vesicles or cysts in 4 cases. All tumors contained the typical small often irregularly shaped spaces but also had prominent cysts. When cysts involved the serosa, the microscopic appearance mimicked that of peritoneal inclusion cysts. In one case with serosal involvement, a prominent papillary pattern was also present. The cysts were typically closely packed with minimal intervening stroma but were occasionally separated by conspicuous smooth muscle bundles. The stroma in one case was extensively hyalinized. Two tumors were focally infarcted. A striking, but minor, solid growth in which the tumor cells were arranged in tightly packed nests or interanastomosing cords and trabeculae was seen in 2 tumors. The unusual gross and microscopic features of these tumors can cause significant diagnostic difficulty and bring into the differential diagnosis entities that are usually not realistic considerations. The presentation of 2 tumors in a curettage specimen represents an unusual clinical aspect.

Macroscopic and microscopic characteristics of low grade appendiceal mucinous neoplasms (LAMN) on appendectomy specimens and correlations with pseudomyxoma peritonei development risk.

Low grade appendiceal mucinous neoplasm (LAMN) is the primary source of pseudomyxoma peritonei (PMP). PMP may develop after seemingly complete resection of primary tumor by appendectomy, which is unpredictable due to lack of reliable prognostic indicators. We retrospectively reviewed 154 surgically resected LAMNs to explore if any of the macroscopic and microscopic characteristics may be associated with increasing risk of PMP development. Our major findings include: (1) As compared to those without PMP, the cases that developed PMP were more frequent to have (a) smaller luminal diameter (<1 cm) and thicker wall, separate mucin aggregations, and microscopic perforation/rupture, all suggestive of luminal mucin leakage; (b) microscopic acellular mucin presenting on serosal surface and not being confined to mucosa; and (c) neoplastic epithelium dissecting outward beyond mucosa, however, with similar frequency of neoplastic cells being present in muscularis propria. (2) Involvement of neoplastic cells or/and acellular mucin at surgical margin did not necessarily lead to tumor recurrence or subsequent PMP, and clear margin did not absolutely prevent PMP development. (3) Coexisting diverticulum, resulted from neoplastic or non-neoplastic mucosa being herniated through muscle-lacking vascular hiatus of appendiceal wall, was seen in a quarter of LAMN cases, regardless of PMP. The diverticular portion of tumor involvement was often the weakest point where rupture occurred. In conclusion, proper evaluation of surgical specimens with search for mucin and neoplastic cells on serosa and for microscopic perforation, which are of prognostic significance, should be emphasized.

Structure and surgical dissection layers of the bare area of the liver.

BACKGROUND: The bare area was reportedly formed by direct adhesion between the liver and diaphragm, meaning that the bare area lacked serosal components. This study aimed to analyze the structure of the bare area by an integrated study of surgical and laparoscopic images and pathological studies and describe surgical procedures focusing on the multilayered structure. METHODS: Several surgical specimens of hepatectomy were analyzed histologically to evaluate the macroscopic structure of the bare area. Laparoscopic images and cadaver anatomy of the bare area were also examined. RESULTS: The multilayered structure of the bare area comprised the liver, sub-serosal connective tissue, liver serosa, parietal peritoneum, retroperitoneal connective tissue, epimysium of the diaphragm, and diaphragm, in order from the liver to the diaphragm. The liver serosa and the parietal peritoneum fused with each other. This multilayered structure of the bare area is observed almost constantly. There are two layers in the dissection of the bare area in surgical procedures, an outer layer of the fused peritoneum (near the diaphragm) and an inner layer of the fused peritoneum (near the liver). Laparoscopic images enabled us to recognize the multilayered structure of the bare area. CONCLUSIONS: Histopathological findings showed the bare area to be a multilayered structure. In cases where tumors are located underneath the bare area, it could be important to dissect the bare area, with careful attention to its multilayered structure. Surgical dissection of the bare area in the outer layer of the fused peritoneum could allow a sufficient safety margin.

Reduced expression of exosomal miR­29s in peritoneal fluid is a useful predictor of peritoneal recurrence after curative resection of gastric cancer with serosal involvement.

The peritoneal surface is the most frequent site of metastasis disease in patients with gastric cancer. Even after curative surgery and adjuvant chemotherapy, peritoneal recurrences often develop. Exosomes play pivotal roles in tumor metastasis via the transfer of microRNAs (miRNAs). In the present study, exosomes were isolated from peritoneal lavage fluid or ascites in 85 patients with gastric cancer and the relative expression levels of miR­29s were examined. The expression of miR­29a­3p, miR­29b­3p and miR­29c­3p in peritoneal exosomes were all downregulated in patients with peritoneal metastases (PM) compared to those without PM. In 30 patients who underwent curative gastrectomy with serosa­involved (T4) gastric cancer, 6 patients exhibited recurrence in the peritoneum within 12 months. The expression levels of miR­29s at gastrectomy tended to be lower in these 6 patients than in the other 24 patients with significant differences in miR­29b­3p (P=0.003). When the patients were divided into two groups based on median levels of miR­29s, peritoneal recurrence developed more frequently in patients with low expression of miR­29b­3p, and lower expression of miR­29s were related with worse overall survival. miR­29s are thought to play a suppressive role in the growth of disseminated peritoneal tumor cells. Reduced expression of miR­29b in peritoneal exosomes is a strong risk factor of developing postoperative peritoneal recurrence.

Microscopic distance from tumor invasion front to serosa might be a useful predictive factor for peritoneal recurrence after curative resection of T3-gastric cancer.

BACKGROUND: Peritoneal recurrence is one of the most frequent recurrent diseases in gastric cancer. Although the exposure of cancer cells to the serosal surface is considered a common risk factor for peritoneal recurrence, there are some cases of peritoneal recurrence without infiltration to the serosal surface even after curative surgery. This study sought to clarify the risk factors of peritoneal recurrence in the absence of invasion to the serosal surface. MATERIALS AND METHODS: Ninety-six patients with gastric cancer who underwent curative surgery were enrolled. In all 96 cases, the depth of tumor invasion was subserosal (T3). The microscopic distance from the tumor invasion front to the serosa (DIFS) was measured using tissue slides by H&E staining and pan-cytokeratin staining. E-cadherin expression was evaluated by immunohistochemical staining. RESULTS: Among the 96 patients, 16 developed peritoneal recurrence after curative surgery. The DIFS of the tumors with peritoneal recurrence (156±220 µm) was significantly shorter (p = 0.011) than that without peritoneal recurrence (360±478 µm). Peritoneal recurrence was significantly correlated with DIFS ≤234 µm (p = 0.023), but not with E-cadherin expression. The prognosis of DIFS ≤234 µm was significantly poorer than that of DIFS >234 µm (log rank, p = 0.007). A multivariate analysis of the patients' five-year overall survival revealed that DIFS ≤234 µm and lymph node metastasis were significantly correlated with survival (p = 0.005, p = 0.032, respectively). CONCLUSION: The measurement of the DIFS might be useful for the prediction of peritoneal recurrence in T3-gastric cancer patients after curative surgery.

"D2 plus" lymphadenectomy is associated with improved survival in distal gastric cancer with clinical serosa invasion: a propensity score analysis.

The aim of this study was to elucidate the potential impact of "D2 plus" lymphadenectomy on the long-term survival of distal gastric cancer (GC) patients with clinical serosa invasion. A total of 394 distal GC patients with clinical serosa invasion who underwent at least standard D2 lymphadenectomy were enrolled. Patients were categorized into two groups according to the extent of lymphadenectomy: D2 group and "D2 plus" group. Propensity score matching was used to adjust for the differences in baseline characteristics. In the multivariate analysis for the whole study series, extent of lymphadenectomy was an independent prognostic factor for GC patients (P = 0.011). With the strata analysis, the significant prognostic differences between the two groups were only observed in patients at the IIIa-b or N1-3a stages. After matching, patients in "D2 plus" group still demonstrated a significantly higher 5-year overall survival rate than those in D2 group (55.3% versus 43.9%, P = 0.042). The common therapeutic value index of No. 12b, No. 12p, No. 14v and No. 13 LNs was 4.6, which was close to that of No. 5 LN station. In conclusion, "D2 plus" lymphadenectomy may be associated with improved overall survival in distal GC with clinical serosa invasion.

[Rise and mix of membrane anatomy].

Membrane anatomy is in broad sense the anatomy of the mesentery and its bed, both of which are consisted of fascia membrane or/and serous membrane. Although the traditional mesentery has the definition of mesentery, people unconsciously identify them according to their "fan-shaped" and "free" characteristics. The "generalized mesentery" we propose refers to the fascia and/or serosa, envelope-like organs and their blood vessels, suspending to the posterior wall of the body, regardless of its shape, free or not. So the main points of the anatomy are as follows.(1) Organs or tissues with their feeding structures are enveloped by the fascia membrane or/and serous membrane, suspending to posterior wall of the body, to form different shapes of the mesentery in broad sense, and most of them are buried in the mesentery bed. (2) Cancer metastasis type V of in the gut moves in the envelop of the mesentery in broad sense.(3) Intraoperative breach of the envelop membrane not only results in intraoperative bleeding, but also cancer cell leakage from the mesentery. (4) The cancer of gut can be divided into cancer in the mesentery, cancer out of the mesentery and cancer at edge of the mesentery based on this anatomy. Radical tumor resection is effective for cancer in the mesentery, which should not be artificially breached into those of cancer out of the mesentery. The essence of neoadjuvant chemoradiation is to push cancer at edge of the mesentery back inside the mesentery.(5) Based on such anatomy, radical gut tumor operations are divided into D2/D3 procedure, without emphasizing the integrity of the mesentery during lymphatic dissection; CME procedure, which emphasizes the integrity of the mesentery but does not strictly define the extent of lymphatic dissection; D2/D3 + CME procedure, which strictly defines the integrity of the mesentery and the extent of lymphatic dissection.(6)For gastrointestinal tumors of the same T stage, shorter mesentery indicates worse prognosis.(7) For gastrointestinal tumors with the same T stage and the same length of mesentery, the more mesentery buried in the mesentery bed, the worse prognosis. (8) The above seven principles are universal in the organs of the body cavity (and even all internal organs).Membrane anatomy, unlike traditional "plane surgery" , is completely different from the "anatomy of the membrane..." described by Japanese scholars, but mainly bases on generalized mesentery and mesentery bed, meanwhile inherent life events can be accurately defined and confirmed.