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BACKGROUND Because of the powerful abilities of self-learning and handling complex biological information, artificial neural network (ANN) models have been widely applied to disease diagnosis, imaging analysis, and prognosis prediction. However, there has been no trained preoperative ANN (preope-ANN) model to preoperatively predict the prognosis of patients with gastric cancer (GC). AIM To establish a neural network model that can predict long-term survival of GC patients before surgery to evaluate the tumor condition before the operation. METHODS The clinicopathological data of 1608 GC patients treated from January 2011 to April 2015 at the Department of Gastric Surgery, Fujian Medical University Union Hospital were analyzed retrospectively. The patients were randomly divided into a training set (70%) for establishing a preope-ANN model and a testing set (30%). The prognostic evaluation ability of the preope-ANN model was compared with that of the American Joint Commission on Cancer (8th edition) clinical TNM (cTNM) and pathological TNM (pTNM) staging through the receiver operating characteristic curve, Akaike information criterion index, Harrell's C index, and likelihood ratio chi-square. RESULTS We used the variables that were statistically significant factors for the 3-year overall survival as input-layer variables to develop a preope-ANN in the training set. The survival curves within each score of the preope-ANN had good discrimination (P < 0.05). Comparing the preope-ANN model, cTNM, and pTNM in both the training and testing sets, the preope-ANN model was superior to cTNM in predictive discrimination (C index), predictive homogeneity (likelihood ratio chi-square), and prediction accuracy (area under the curve). The prediction efficiency of the preope-ANN model is similar to that of pTNM. CONCLUSION The preope-ANN model can accurately predict the long-term survival of GC patients, and its predictive efficiency is not inferior to that of pTNM stage.

BACKGROUND Robotic surgery has been considered to be significantly better than laparoscopic surgery for complicated procedures. AIM To explore the short-term effect of robotic and laparoscopic spleen-preserving splenic hilar lymphadenectomy (SPSHL) for advanced gastric cancer (GC) by Huang’s three-step maneuver. METHODS A total of 643 patients who underwent SPSHL were recruited from April 2012 to July 2017, including 35 patients who underwent robotic SPSHL (RSPSHL) and 608 who underwent laparoscopic SPSHL (LSPSHL). One-to-four propensity score matching was used to analyze the differences in clinical data between patients who underwent robotic SPSHL and those who underwent laparoscopic SPSHL. RESULTS In all, 175 patients were matched, including 35 patients who underwent RSPSHL and 140 who underwent LSPSHL. After matching, there were no significant differences detected in the baseline characteristics between the two groups. Significant differences in total operative time, estimated blood loss (EBL), splenic hilar blood loss (SHBL), splenic hilar dissection time (SHDT), and splenic trunk dissection time were evident between these groups (P < 0.05). Furthermore, no significant differences were observed between the two groups in the overall noncompliance rate of lymph node (LN) dissection (62.9% vs 60%, P = 0.757), number of retrieved No. 10 LNs (3.1 ± 1.4 vs 3.3 ± 2.5, P = 0.650), total number of examined LNs (37.8 ± 13.1 vs 40.6 ± 13.6, P = 0.274), and postoperative complications (14.3% vs 17.9%, P = 0.616). A stratified analysis that divided the patients receiving RSPSHL into an early group (EG) and a late group (LG) revealed that the LG experienced obvious improvements in SHDT and length of stay compared with the EG (P < 0.05). Logistic regression showed that robotic surgery was a significantly protective factor against both SHBL and SHDT (P < 0.05). CONCLUSION RSPSHL is safe and feasible, especially after overcoming the early learning curve, as this procedure results in a radical curative effect equivalent to that of LSPSHL.

BACKGROUND Anastomotic leakage (AL) is a severe complication associated with high morbidity and mortality after radical gastrectomy (RG) for gastric cancer (GC). We hypothesized that a novel abdominal negative pressure lavage-drainage system (ANPLDS) can effectively reduce the failure-to-rescue (FTR) and the risk of reoperation, and it is a feasible management for AL. AIM To report our institution’s experience with a novel ANPLDS for AL after RG for GC. METHODS The study enrolled 4173 patients who underwent R0 resection for GC at our institution between June 2009 and December 2016. ANPLDS was routinely used for patients with AL after January 2014. Characterization of patients who underwent R0 resection was compared between different study periods. AL rates and postoperative outcome among patients with AL were compared before and after the ANPLDS therapy. We used multivariate analyses to evaluate clinicopathological and perioperative factors for associations with AL and FTR after AL. RESULTS AL occurred in 83 (83/4173, 2%) patients, leading to 7 deaths. The mean time of occurrence of AL was 5.6 days. The AL rate was similar before (2009-2013, period 1) and after (2014-2016, period 2) the implementation of the ANPLDS therapy (1.7% vs 2.3%, P = 0.121). Age and malnourishment were independently associated with AL. The FTR rate and abdominal bleeding rate after AL occurred were respectively 8.4% and 9.6% for the entire period; however, compared with period 1, this significantly decreased during period 2 (16.2% vs 2.2%, P = 0.041; 18.9% vs 2.2%, P = 0.020, respectively). Moreover, the reoperation rate was also reduced in period 2, although this result was not statistically significant (13.5% vs 2.2%, P = 0.084). Additionally, only ANPLDS therapy was an independent protective factor for FTR after AL (P = 0.04). CONCLUSION Our experience demonstrates that ANPLDS is a feasible management for AL after RG for GC.

To investigate the effects of different levels of expression of CDK5RAP3 and DDRGK1 on long-term survival of patients undergoing radical gastrectomy.The expression of CDK5RAP3 and DDRGK1 was detected by immunohistochemistry in 135 patients who received standard gastrectomy were enrolled in the study. Western Blot was used to detect the expression of CDK5RAP3 and DDRGK1 in gastric cancer and its adjacent tissues and cell lines. The correlations between the expression of CDK5RAP3 and DDRGK1 and clinicopathological factors were analyzed, and the value of each parameter to the prognosis of the patients was compared. Receiver operating characteristic analysis was used to compare the accuracy of the prediction of clinical outcome by the parameters.CDK5RAP3 and DDRGK1 expression was down-regulated in the gastric cancer compared to its respective adjacent non-tumor tissues. The expression of CDK5RAP3 was closely related to the age of the patients (The co-expression of CDK5RAP3 and DDRGK1 is an independent prognostic factor for gastric cancer, which can provide a more accurate model for the long-term prognosis.

AIM To assess the predictive value of the tumor-associated neutrophil-to-lymphocyte ratio in terms of the clinical outcomes of patients with gastric neuroendocrine neoplasms after radical surgery. METHODS Data were retrospectively collected from 142 patients who were diagnosed with gastric neuroendocrine neoplasms and who underwent radical gastrectomy at our department from March 2006 to March 2015. These data were retrospectively analyzed, and a receiver operating characteristic curve analysis was used to identify the optimal value of the tumor-associated neutrophil-to-lymphocyte ratio. Univariate and multivariate survival analyses were used to identify prognostic factors. A nomogram was then applied to predict clinical outcomes after surgery. RESULTS The tumor-associated neutrophil-to-lymphocyte ratio was significantly associated with tumor recurrence, especially with liver metastasis and lymph node metastasis (P < 0.05 for both), but not with clinical characteristics (P > 0.05 for all). A multivariate Cox regression analysis identified the tumor-associated neutrophil-to-lymphocyte ratio as an independent prognostic factor for recurrence-free survival and overall survival (P < 0.05 for both). The concordance index of the nomograms, which included the tumor-associated neutrophil-to-lymphocyte ratio, Ki-67 index, and lymph node ratio, was 0.788 (0.759) for recurrence-free survival (overall survival) and was higher than the concordance index of the traditional TNM staging system [0.672 (0.663)]. CONCLUSION The tumor-associated neutrophil-to-lymphocyte ratio is an independent prognostic factor in patients with gastric neuroendocrine neoplasms. Nomograms that include the tumor-associated neutrophil-to-lymphocyte ratio, Ki-67 index, and lymph node ratio have a superior ability to predict clinical outcomes of postoperative patients.

AIM To evaluate the short-term outcomes and quality of life (QoL) in gastric cancer patients undergoing digestive tract construction using the isoperistaltic jejunum-later-cut overlap method (IJOM) after totally laparoscopic total gastrectomy (TLTG). METHODS A total of 507 patients who underwent laparoscopic gastrectomy (D2) from January 2014 to March 2016 were originally included in the study. The patients were divided into two groups to undergo digestive tract construction using either IJOM after TLTG (group T, n = 51) or Roux-en-Y anastomosis after laparoscopic-assisted total gastrectomy (LATG) (group A, n = 456). The short-term outcomes and QoL were compared between the two groups after 1:2 propensity-score matching (PSM). We used a questionnaire to assess QoL. RESULTS Before matching, age, sex, tumor size, tumor location, preoperative albumin and blood loss were significantly different between the two groups (P < 0.05). After PSM, the patients were well balanced in terms of their clinicopathological characteristics, although both blood loss and in-hospital postoperative days in group T were significantly lower than those in group A (P < 0.05). After matching, group T reported better QoL in the domains of pain and dysphagia. Among the items evaluating pain and dysphagia, group T tended to report better QoL (“Have you felt pain” and “Have you had difficulty eating solid food”) (P < 0.05). CONCLUSION The IJOM for digestive tract reconstruction after TLTG is associated with reduced blood loss and less pain and dysphagia, thus improving QoL after laparoscopic gastrectomy.

Background Increasing numbers of laboratory blood parameters (BPM) have been reported to greatly affect the long-term outcomes of gastric cancer (GC) patients. However, the existing prognostic models do not comprehensively analyze these predictors. Aim To construct a new prognostic tool, based on all the prognostic BPM, to achieve more accurate prognosis prediction for GC. Methods We retrospectively assessed 850 consecutive patients who underwent curative resection for stage II-III GC from January 2010 to April 2013. The patients were classified into developing (n = 567) and validation (n = 283) cohorts using computer-generated random numbers. A scoring system, namely BPM score, was then constructed using least absolute shrinkage and selection operator (LASSO) Cox regression model in the developing cohort, and validated in the validation cohort. A nomogram consisting of BPM score and tumor-lymph node-metastasis (TNM) stage was further created. The discrimination and calibration of the nomogram were evaluated via Harrell's C-statistic and the Hosmer-Lemeshow test. Results Using the LASSO model, we established the BPM score based on five BPM: Albumin, lymphocyte-to-monocyte ratio, neutrophil-to-lymphocyte ratio, carcinoembryonic antigen, and carbohydrate antigen 19-9. The BPM scores were divided into high- and low-BPM groups based on a cut-off value of -0.93. High-BPM patients were significantly older and had more advanced, larger tumors. In the developing cohort, significant differences were found in 5-year overall survival (OS) and 5-year disease-specific survival between the high-BPM and low-BPM patients. Similar results were found in the validation group. Multivariable analysis showed that the BPM score was an independent predictor of OS. High-BPM patients had a poorer 5-year OS for each subgroup. Furthermore, a nomogram that combined the BPM score and TNM stage had significantly better prognostic value compared with TNM stage alone. Conclusion The BPM score provides more accurate prognosis prediction in stage II-III GC patients and is an effective complement to the TNM staging system.

AIM: To investigate the splenic hilar vascular anatomy and the influence of splenic artery (SpA) type in laparoscopic total gastrectomy with spleen-preserving splenic lymphadenectomy (LTGSPL). METHODS: The clinical anatomy data of 317 patients with upper- or middle-third gastric cancer who underwent LTGSPL in our hospital from January 2011 to December 2013 were collected. The patients were divided into two groups (concentrated group vs distributed group) according to the distance between the splenic artery’s furcation and the splenic hilar region. Then, the anatomical layout, clinicopathologic characteristics, intraoperative variables, and postoperative variables were compared between the two groups. RESULTS: There were 205 patients with a concentrated type (64.7%) and 112 patients with a distributed type (35.3%) SpA. There were 22 patients (6.9%) with a single branch of the splenic lobar vessels, 250 (78.9%) with 2 branches, 43 (13.6%) with 3 branches, and 2 patients (0.6%) with multiple branches. Eighty seven patients (27.4%) had type I splenic artery trunk, 211 (66.6%) had type II, 13 (4.1%) had type III, and 6 (1.9%) had type IV. The mean splenic hilar lymphadenectomy time (23.15 ± 8.02 vs 26.21 ± 8.84 min; P = 0.002), mean blood loss resulting from splenic hilar lymphadenectomy (14.78 ± 11.09 vs 17.37 ± 10.62 mL; P = 0.044), and number of vascular clamps used at the splenic hilum (9.64 ± 2.88 vs 10.40 ± 3.57; P = 0.040) were significantly lower in the concentrated group than in the distributed group. However, the mean total surgical time, mean total blood loss, and the mean number of harvested splenic hilar lymph nodes were similar in both groups (P > 0.05 for each comparison). There were also no significant differences in clinicopathological and postoperative characteristics between the groups (P > 0.05). CONCLUSION: It is of value for surgeons to know the splenic hilar vascular anatomy when performing LTGSPL. Patients with concentrated type SpA may be optimal patients for training new surgeons.

Aim To evaluate the predictive value of the expression of chromosomal maintenance (CRM)1 and cyclin-dependent kinase (CDK)5 in gastric cancer (GC) patients after gastrectomy. Methods A total of 240 GC patients who received standard gastrectomy were enrolled in the study. The expression level of CRM1 and CDK5 was detected by immunohistochemistry. The correlations between CRM1 and CDK5 expression and clinicopathological factors were explored. Univariate and multivariate survival analyses were used to identify prognostic factors for GC. Receiver operating characteristic analysis was used to compare the accuracy of the prediction of clinical outcome by the parameters. Results The expression of CRM1 was significantly related to size of primary tumor (P = 0.005), Borrmann type (P = 0.006), degree of differentiation (P = 0.004), depth of invasion (P = 0.008), lymph node metastasis (P = 0.013), TNM stage (P = 0.002) and distant metastasis (P = 0.015). The expression of CDK5 was significantly related to sex (P = 0.048) and Lauren's classification (P = 0.011). Multivariate Cox regression analysis identified that CRM1 and CDK5 co-expression status was an independent prognostic factor for overall survival (OS) of patients with GC. Integration of CRM1 and CDK5 expression could provide additional prognostic value for OS compared with CRM1 or CDK5 expression alone (P = 0.001). Conclusion CRM1 and CDK5 co-expression was an independent prognostic factors for GC. Combined CRM1 and CDK5 expression could provide a prognostic model for OS of GC.

To report the incidence and potential risk factors of small-volume chylous ascites (SVCA) following laparoscopic radical gastrectomy (LAG).A total of 1366 consecutive gastric cancer patients who underwent LAG from January 2008 to June 2011 were enrolled in this study. We analyzed the patients based on the presence or absence of SVCA.SVCA was detected in 57 (4.17%) patients, as determined by the small-volume drainage (range, 30-100 mL/24 h) of triglyceride-rich fluid. Both univariate and multivariate analyses revealed that the total number of resected lymph nodes (LNs), No. 8 or No. 9 LN metastasis and N stage were independent risk factors for SVCA following LAG (P0.05). Regarding hospital stay, there was a significant difference between the groups with and without SVCA (P0.001). The 3-year disease-free and overall survival rates of the patients with SVCA were 47.4% and 56.1%, respectively, which were similar to those of the patients without SVCA (P0.05).SVCA following LAG developed significantly more frequently in the patients with ≥32 harvested LNs, ≥3 metastatic LNs, or No. 8 or No. 9 LN metastasis. SVCA, which was successfully treated with conservative management, was associated with a prolonged hospital stay but was not associated with the prognosis.

To evaluate the feasibility and short-term efficacy of laparoscopic spleen-preserving splenic hilar (No. 10) lymphadenectomy to treat advanced upper gastric cancer (AUGC).Between January and December 2012, 108 laparoscopic spleen-preserving No. 10 lymphadenectomy along with total gastrectomy with routine D2 lymphadenectomy were performed consecutively at our hospital to treat clinical T2-3 (cT2-3) upper gastric cancers. The preoperative clinical T stage was cT2 in 36 patients and cT3 in 72 patients. A prospectively designed database tracked the 108 patients, including the completeness of their medical records and the adequacy of follow-up. Patient clinicopathological characteristics, intraoperative and postoperative surgical outcomes, morbidity and mortality, lymph node (LN) dissection, and postoperative follow-up were analysed retrospectively.Laparoscopic spleen-preserving No. 10 lymphadenectomy was successful in all 108 patients. The mean operation time was 169.3 ± 27.1 min, and the mean No. 10 lymphadenectomy time was 20.0 ± 5.7 min. The mean total blood loss was 46.2 ± 11.3 mL, and the mean blood loss from No. 10 lymphadenectomy was 14.3 ± 3.8 mL. The mean postoperative hospital stay was 11.9 ± 6.0 d. The intraoperative and postoperative morbidity rates were 3.7% and 12.0%, respectively; however, there was no postoperative mortality. A mean of 44.4 ± 17.6 LNs were retrieved from each specimen, including 3.0 ± 2.4 No. 10 LNs. Three patients (2.8%) with cT3 cancer had LN metastasis of the splenic hilus, including two patients with pathological T3 (pT3) and one patient with pathological T4a (pT4a) tumours, all located in the greater curvature. No splenic hilar LNs metastasis was evident in the patients with pT1 and pT2 tumours. At a median follow-up time of 18 mo (range, 12 to 23 mo), all patients were alive and none had experienced recurrent or metastatic disease.Laparoscopic spleen-preserving No. 10 lymphadenectomy is feasible and effective to treat AUGC. Routine No. 10 lymphadenectomy may be unnecessary for AUGC without serosa invasion, unless T3 tumours are located in the greater curvature.

To explore the impact of tumor size on outcomes in patients with advanced gastric cancer in the lower third of the stomach.We retrospectively analyzed the clinical records of 430 patients with advanced gastric cancer in the lower third of the stomach who underwent distal subtotal gastrectomy and D2 lymphadenectomy in our hospital from January 1998 to June 2004. Receiver-operating characteristic (ROC) curve analysis was used to determine the appropriate cutoff value for tumor size, which was measured as maximum tumor diameter. Based on this cutoff value, patients were divided into two groups: those with large-sized tumors (LSTs) and those with small-sized tumors (SSTs). The correlations between other clinicopathologic factors and tumor size were investigated, and the 5-year overall survival (OS) rate was compared between the two groups. Potential prognostic factors were evaluated by univariate Kaplan-Meier survival analysis and multivariate Cox's proportional hazard model analysis. The 5-year OS rates in the two groups were compared according to pT stage and pN stage.The 5-year OS rate in the 430 patients with advanced gastric cancer in the lower third of the stomach was 53.7%. The mean ± SD tumor size was 4.9 ± 1.9 cm, and the median tumor size was 5.0 cm. ROC analysis indicated that the sensitivity and specificity results for the appropriate tumor size cutoff value of 4.8 cm were 80.0% and 68.2%, respectively (AUC = 0.795, 95%CI: 0.751-0.839, P = 0.000). Using this cutoff value, 222 patients (51.6%) had LSTs (tumor size ≥ 4.8 cm) and 208 (48.4%) had SSTs (tumor size4.8 cm). Tumor size was significantly correlated with histological type (P = 0.039), Borrmann type (P = 0.000), depth of tumor invasion (P = 0.000), lymph node metastasis (P = 0.000), tumor-nodes metastasis stage (P = 0.000), mean number of metastatic lymph nodes (P = 0.000) and metastatic lymph node ratio (P = 0.000). Patients with LSTs had a significantly lower 5-year OS rate than those with SSTs (37.1% vs 63.3%, P = 0.000). Univariate analysis showed that depth of tumor invasion (χ² = 69.581, P = 0.000), lymph node metastasis (χ² = 138.815, P = 0.000), tumor size (χ² = 78.184, P = 0.000) and metastatic lymph node ratio (χ² = 139.034, P = 0.000) were significantly associated with 5-year OS rate. Multivariate analysis revealed that depth of tumor invasion (P = 0.000), lymph node metastasis (P = 0.019) and tumor size (P = 0.000) were independent prognostic factors. Gastric cancers were divided into 12 subgroups: pT2N0; pT2N1; pT2N2; pT2N3; pT3N0; pT3N1; pT3N2; pT3N3; pT4aN0; pT4aN1; pT4aN2; and pT4aN3. In patients with pT2-3N3 stage tumors and patients with pT4a stage tumors, 5-year OS rates were significantly lower for LSTs than for SSTs (P0.05 each), but there were no significant differences in the 5-year OS rates in LST and SST patients with pT2-3N0-2 stage tumors (P0.05).Using a tumor size cutoff value of 4.8 cm, tumor size is a prognostic factor in patients with pN3 stage or pT4a stage advanced gastric cancer located in the lower third of the stomach.

To investigate the long-term effect of the number of resected lymph nodes (LNs) on the prognosis of patients with node-negative gastric cancer.Clinical data of 211 patients with gastric cancer, without nodal involvement, were analyzed retrospectively after D2 radical operation. We analyzed the relationship between the number of resected LNs with the 5-year survival, the recurrence rate and the post-operative complication rate.The 5-year survival of the entire cohort was 82.2%. The total number of dissected LNs was one of the independent prognostic factors. Among patients with comparable depth of invasion, the larger the number of resected LNs, the better the survival (P0.05). A cut-point analysis provided the possibility to detect a significant survival difference among subgroups. Patients had a better long-term survival outcomes with LN countsor = 15 for pT1-2,or = 20 for pT3-4, andor = 15 for the entire cohort. The overall recurrence rate was 29.4% within 5 years after surgery. There was a statistically significant, negative correlation between the number of resected LNs and the recurrence rate (P0.01). The post-operative complication rate was 10.9% and was not significantly correlated with the number of dissected LNs (P0.05).For node-negative gastric cancer, sufficient number of dissected LNs is recommended during D2 lymphadenectomy, to improve the long-term survival and reduce the recurrence. Suitable increments of the dissected LN count would not increase the post-operative complication rate.

AIM: To evaluate the safety and feasibility of a modified delta-shaped gastroduodenostomy (DSG) in totally laparoscopic distal gastrectomy (TLDG). METHODS: We performed a case-control study enrolling 63 patients with distal gastric cancer (GC) undergoing TLDG with a DSG from January 2013 to June 2013. Twenty-two patients underwent a conventional DSG (Con-Group), whereas the other 41 patients underwent a modified version of the DSG (Mod-Group). The modified procedure required only the instruments of the surgeon and assistant to complete the involution of the common stab incision and to completely resect the duodenal cutting edge, resulting in an anastomosis with an inverted T-shaped appearance. The clinicopathological characteristics, surgical outcomes, anastomosis time and complications of the two groups were retrospectively analyzed using a prospectively maintained comprehensive database. RESULTS: DSG procedures were successfully completed in all of the patients with histologically complete (R0) resections, and none of these patients required conversion to open surgery. The clinicopathological characteristics of the two groups were similar. There were no significant differences between the groups in the operative time, intraoperative blood loss, extension of the lymph node (LN) dissection and number of dissected LNs (150.8 ± 21.6 min vs 143.4 ± 23.4 min, P = 0.225 for the operative time; 26.8 ± 11.3 min vs 30.6 ± 14.8 mL, P = 0.157 for the intraoperative blood loss; 4/18 vs 3/38, P = 0.375 for the extension of the LN dissection; and 43.9 ± 13.4 vs 39.5 ± 11.5 per case, P = 0.151 for the number of dissected LNs). The anastomosis time, however, was significantly shorter in the Mod-Group than in the Con-Group (13.9 ± 2.8 min vs 23.9 ± 5.6 min, P = 0.000). The postoperative outcomes, including the times to out-of-bed activities, first flatus, resumption of soft diet and postoperative hospital stay, as well as the anastomosis size, did not differ significantly (1.9 ± 0.6 d vs 2.3 ± 1.5 d, P = 0.228 for the time to out-of-bed activities; 3.2 ± 0.9 d vs 3.5 ± 1.3 d, P = 0.295 for the first flatus time; 7.5 ± 0.8 d vs 8.1 ± 4.3 d, P = 0.489 for the resumption of a soft diet time; 14.3 ± 10.6 d vs 11.5 ± 4.9 d, P = 0.148 for the postoperative hospital stay; and 30.5 ± 3.6 mm vs 30.1 ± 4.0 mm, P = 0.730 for the anastomosis size). One patient with minor anastomotic leakage in the Con-Group was managed conservatively; no other patients experienced any complications around the anastomosis. The operative complication rates were similar in the Con- and Mod-Groups (9.1% vs 7.3%, P = 1.000). CONCLUSION: The modified DSG, an alternative reconstruction in TLDG for GC, is technically safe and feasible, with a simpler process that reduces the anastomosis time.

To investigate the prognostic impact of metastatic lymph node ratio (rN) on gastric cancer after curative distal gastrectomy.A total of 634 gastric cancer patients who underwent curative resection (R0) of lymph nodes at distal gastrectomy in 1995-2004. Correlations between positive nodes and retrieved nodes, between rN and retrieved nodes, and between rN and negative lymph node (LN) count were analyzed respectively. Prognostic factors were identified by univariate and multivariate analyses. Staging accuracy of the pN category (5th UICC/TNM system) and the rN category was compared according to the survival rates of patients. A linear regression model was used to identify the relation between rN and 5-year survival rate of the patients.The number of dissected LNs was related with metastatic LNs but not related with rN. Cox regression analysis showed that depth of invasion, pN and rN category were the independent predictors of survival (P0.05). There was a significant difference in survival between LN stages classified by the rN category or by the pN category (P0.05). However, no significant difference was found in survival rate between LN stages classified by the pN category or by the rN category (P0.05). Linear regression model showed a significant linear correlation between rN and the 5-year survival rate of gastric cancer patients (beta = 0.862, P0.001). Pearson's correlation test revealed that negative LN count was negatively correlated with rN (P0.001).rN category is a better prognostic tool than the 5th UICC pN category for gastric cancer patients after curative distal gastrectomy. Increased negative LN count can reduce rN and improve the survival rate of gastric cancer patients.

AIM: To investigate the prognostic impact of the metastatic lymph node ratio (MLR) in advanced gastric cancer from the cardia and fundus. METHODS: Two hundred and thirty-six patients with gastric cancer from the cardia and fundus who underwent D2 curative resection were analyzed retrospectively. The correlations between MLR and the total lymph nodes, positive nodes and the total lymph nodes were analyzed respectively. The influence of MLR on the survival time of patients was determined with univariate Kaplan-Meier survival analysis and multivariate Cox proportional hazard model analysis. And the multiple linear regression was used to identify the relation between MLR and the 5-year survival rate of the patients. RESULTS: The MLR did not correlate with the total lymph nodes resected (r = -0.093, P = 0.057). The 5-year overall survival rate of the whole cohort was 37.5%. Kaplan-Meier survival analysis identified that the following eight factors influenced the survival time of the patients postoperatively: gender (χ2 = 4.26, P = 0.0389), tumor size (χ2 = 18.48, P < 0.001), Borrmann type (χ2 = 7.41, P = 0.0065), histological grade (χ2 = 5.07, P = 0.0243), pT category (χ2 = 49.42, P < 0.001), pN category (χ2 = 87.7, P < 0.001), total number of retrieved lymph nodes (χ2 = 8.22, P = 0.0042) and MLR (χ2 = 34.3, P < 0.001). Cox proportional hazard model showed that tumor size (χ2 = 7.985, P = 0.018), pT category (χ2 = 30.82, P < 0.001) and MLR (χ2 = 69.39, P < 0.001) independently influenced the prognosis. A linear correlation between MLR and the 5-year survival was statistically significant based on the multiple linear regression (β = -0.63, P < 0.001). Hypothetically, the 5-year survival would surpass 50% when MLR was lower than 10%. CONCLUSION: The MLR is an independent prognostic factor for patients with advanced gastric cancer from the cardia and fundus. The decrease of MLR due to adequate number of total resected lymph nodes can improve the survival.

AIM: To analyze the prognostic impact of lymphade-nectomy extent in advanced gastric cancer located in the cardia and fundus. METHODS: Two hundred and thirty-six patients with advanced gastric cancer located in the cardia and fundus who underwent D2 curative resection were analyzed retrospectively. Relationships between the numbers of lymph nodes (LNs) dissected and survival was analyzed among different clinical stage subgroups. RESULTS: The 5-year overall survival rate of the entire cohort was 37.5%. Multivariate prognostic variables were total LNs dissected (P < 0.0001; or number of negative LNs examined, P < 0.0001), number of positive LNs (P < 0.0001), T category (P < 0.0001) and tumor size (P = 0.015). The greatest survival differences were observed at cutoff values of 20 LNs resected for stage II (P = 0.0136), 25 for stage III(P < 0.0001), 30 for stage IV (P = 0.0002), and 15 for all patients (P = 0.0024). Based on the statistically assumed linearity as best fit, linear regression showed a significant survival enhancement based on increasing negative LNs for patients of stages III (P = 0.013) and IV (P = 0.035). CONCLUSION: To improve the long-term survival of patients with advanced gastric cancer located in the cardia and fundus, removing at least 20 LNs for stage II, 25 LNs for stage III, and 30 LNs for stage IVpatients during D2 radical dissection is recommended.