Comparative Analysis of Various Weight Loss Success Criteria Models After Bariatric Metabolic Surgery in Korean Morbid Obese Patients.

Purpose: To identify weight loss prediction models by validating previous models using weight loss success criteria. Materials and Methods: Patients with morbid obesity from 4 hospitals were retrospectively analyzed between Jan 2019 and 2022. Preoperative demographics, postoperative data, and 1-year follow-up weight loss outcomes were compared between 2 groups who underwent laparoscopic sleeve gastrectomy (LSG) and laparoscopic Roux-en-Y gastric bypass (LRYGB). Additionally, the predictive factors for the success of excess weight loss (EWL) (>50%) and total weight loss (TWL) (>25%) were analyzed. Results: Of the 162 patients, 137 were enrolled during the study period, 75 underwent LSG, and 62 underwent LRYGB. The >50% EWL and >25% TWL 1 year after surgery were 61.3% and 43.1%, respectively. Diabetes mellitus medication use was reduced in 94.8% of patients with type 2 diabetes mellitus. Male sex and body mass index (BMI) were independent risk factors for successful weight loss (SWL) or >50% EWL (odds ratio [OR] for BMI 0.830, 95% confidence interval [CI] 0.764-0.902), whereas achieving >25% TWL was not affected by sex or BMI (OR for BMI 1.010, 95% CI 0.957-1.065). External validation of the prediction models showed an acceptable range of accuracy (adjusted R2 66.5-71.3%). Conclusion: LSG and LRYGB are feasible and effective bariatric procedures for SWL in Korean patients with morbid obesity. The TWL model was a more appropriate criterion than EWL, and weight loss prediction models may help assess the 1-year outcomes of bariatric surgery.

Survival impact of compliance in extra-perigastric lymphadenectomy for gastric cancer: 20 years of real-world data from a single institution.

BACKGROUND: Compliance in lymphadenectomy was first introduced as part of quality control in a Dutch clinical trial. Although a few studies have investigated compliance, no studies have evaluated the survival impact at individual lymph node stations. METHODS: In total, 2,932 patients who underwent radical gastrectomy between 1996 and 2014 at the Korea University Guro Hospital in Seoul, South Korea were retrospectively reviewed. We compared survival outcomes among the compliance, noncompliance, and metastatic groups. RESULTS: The highest compliance among extra-perigastric stations was recorded for #8a (86.6%), followed by #7 (76.6%) and #9 (68.3%). Stations #11 and #12 showed low compliance rates of 28.9% and 31.0%, respectively. Compliance at #7, #8a, and #9 was related to better 5-year relapse-free survival rates (74.5%, 72.8%, and 71.3%, respectively) than noncompliance (61.9% [hazard ratio, 1.72; 95% confidence interval, 1.40-2.11], 61.0% [hazard ratio, 1.6; 95% confidence interval 1.26-2.04], 65.3% [hazard ratio, 1.25; 95% confidence interval 1.04-1.51], respectively). At #11 and #12, there were no significant differences in relapse-free survival between compliance (69.1% and 70.2%, respectively) and noncompliance (67.4% [hazard ratio, 0.85; 95% confidence interval 0.53-1.36], 65.1% [hazard ratio, 1.13; 95% confidence interval 0.71-1.81], respectively). In multivariable analysis, stations #7 and #8 alone showed an increased hazard ratio of relapse-free survival in the noncompliance group relative to the compliance group. CONCLUSION: We showed a survival benefit of compliance during lymphadenectomy for gastric cancer. Although further prospective trials to validate our results are warranted, compliance could be adopted in real-world practice to achieve better survival among patients with gastric cancer.

Perioperative, short-, and long-term outcomes of gastric cancer surgery: Propensity score-matched analysis of patients with or without prior solid organ transplantation.

BACKGROUND: Details of perioperative outcomes and survival after gastric cancer surgery in prior transplant recipients have received minimal research attention. METHODS: We performed an observational cohort study using the database of 20,147 gastric cancer patients who underwent gastrectomy at a single gastric cancer center in Korea. Forty-one solid organ recipients [kidney (n = 35), liver (n = 5), or heart (n = 1)] were matched with 205 controls using propensity score matching. RESULTS: Operation time, blood loss, and postoperative pain were similar between groups. Short-term complication rates were similar between transplantation and control groups (22.0% vs. 20.1%, P = 0.777). Transplantation group patients with stage 1 gastric cancer experienced no recurrence, while those with stage 2/3 cancer had significantly higher recurrence risk compared to the controls (P = 0.049). For patients with stage 1 cancer, the transplantation group had a significantly higher rate of non-gastric cancer-related deaths compared to the controls (19.2% vs. 1.4%, P = 0.001). For those with stage 2/3 cancer, significantly lower proportion of the transplantation group received adjuvant chemotherapy compared to the control group (26.7% vs. 80.3%, P < 0.001). The transplantation group had a higher (albeit not statistically significant) rate of gastric cancer-related deaths compared to the controls (40.0% vs. 18.0%, P = 0.087). CONCLUSION: Transplant recipients and non-transplant recipients exhibited similar perioperative and short-term outcomes after gastric cancer surgery. From long-term outcome analyses, we suggest active surveillance for non-gastric cancer-related deaths in patients with early gastric cancer, as well as strict oncologic care in patients with advanced cancer, as effective strategies for transplant recipients.

Incidence and treatment outcomes of leakage after gastrectomy for gastric cancer: Experience of 14,075 patients from a large volume centre.

INTRODUCTION: Leakage is a serious and potentially fatal complication of gastrectomy for gastric cancer. However, comprehensive reports regarding leakage after gastrectomy remain limited. We aimed to evaluate the incidence and treatment outcomes of leakage after gastrectomy for cancer. METHODS: We reviewed the prospectively collected data of 14,075 Patients who underwent gastrectomy for gastric cancer between 2005 and 2017. Outcomes included incidence, risk factors of leakage, and leakage treatment outcomes. RESULTS: The median day of leakage detection was postoperative day 7 (range 1-29days). The overall leakage incidence was 1.51% (213/14,075), and the most frequent location was the oesophagojejunostomy (2.07%). Leakage after total gastrectomy was more frequent with minimally invasive surgery (open:1.64%, laparoscopic:3.56%, robotic:5.83%; P < 0.001). Leakage incidence was higher in the surgeon's initial 100 cases than in later cases (2.4 vs. 1.3%; P < 0.001), especially with minimally invasive surgery. Early leakage (within 4 days of surgery) occurred more often after minimally invasive surgery (open:12.7%, laparoscopic:35.4%, robotic:29.0%; P = 0.006). The success rate for initial treatment of leakage was 70.4% (150/213). Surgery after initial treatment failure demonstrated a higher success rate for early leakage than for late leakage (80.0 vs. 22.2%). Among 213 patients who experienced leakage, fifteen patients (7.0%) died, and leakage-related mortality accounted for 38.5% (15/39) of all surgery-related mortality after gastrectomy. CONCLUSIONS: Leakage after gastric cancer surgery is associated with high mortality. Improved surgeon experience using minimally invasive techniques is required to reduce the risk of leakage. Surgery is an effective treatment for early leakage, although further studies are needed to establish the most appropriate treatment strategies.

Omentum preservation as an oncologically comparable and surgically superior alternative to total omentectomy during radical gastrectomy for T3-T4 gastric cancer.

BACKGROUND: Total omentectomy has conventionally been performed and has been regarded as standard procedure in radical gastrectomy for cancer. However, omentum preservation is the preferred procedure during minimally invasive surgery, without sufficient evidence of oncological safety, especially for T3-T4 gastric cancer. METHOD: A total of 3,510 patients who underwent radical gastrectomy for T3-T4 gastric cancer between January 2003 and December 2015 were reviewed, retrospectively. After propensity score matching, 225 patients in the omentum preservation group were compared with 225 patients in the total omentectomy group. The primary outcome was 5-year overall survival. RESULTS: The omentum preservation group showed significantly shorter operation time (P = .001) and less blood loss (P = .004) than the total omentectomy group. Shorter operation time was also observed with both open and minimally invasive approaches (P < .001 and P = .007, respectively). The 5-year overall survival rates were 75.4% for the omentum preservation group and 72.6% for the total omentectomy group (log-rank P = .06; hazard ratio 0.7 [95% confidence interval, 0.48-1.01]). The 5-year relapse-free survival was higher in the omentum preservation group (73.8%) than in the total omentectomy group (66.1%), without statistical significance (log-rank P = .09; hazard ratio 0.74 [95% confidence interval, 0.52-1.06]). CONCLUSION: Regardless of the surgical approach, omentum preservation provided comparable oncologic outcomes with better surgical outcomes, suggesting that this could be an acceptable alternative to total omentectomy for T3-T4 gastric cancer. These findings warrant further investigation in randomized clinical trials.

Intraperitoneal Paclitaxel Combined with S-1 Plus Oxaliplatin for Advanced Gastric Cancer with Peritoneal Metastasis: a Phase I Study.

PURPOSE: We designed a new regimen by combining intraperitoneal (IP) paclitaxel (PTX) with systemic S-1 plus oxaliplatin (SOX) for the treatment of advanced gastric cancer with peritoneal metastasis. This dose-escalation study aimed to determine the maximum tolerated dose (MTD) and recommended dose (RD) of IP PTX administered weekly to patients. MATERIALS AND METHODS: Eight cycles of IP PTX plus SOX regimen were administered to the patients. S-1 was administered orally twice daily at a dose of 80 mg/m2/day for 14 consecutive days, followed by 7 days of rest. Intravenous oxaliplatin was administered at a fixed dose of 100 mg/m2 on day 1, while IP PTX was administered on days 1 and 8. The initial dose of IP PTX was 40 mg/m2, and the dose escalation was set in units of 20 mg/m2 up to 80 mg/m2. Dose-limiting toxicities (DLTs) were defined as grade 3 non-hematologic toxicities, grade 4 leukopenia, grade 3 febrile neutropenia, and grade 3 thrombocytopenia. RESULTS: Nine patients were included in the study. No DLTs were observed in any of the enrolled patients. Therefore, the MTD was not reached, and the RD of IP PTX was determined to be 80 mg/m2. Four patients (44%) showed a decreased peritoneal cancer index score on second-look laparoscopic examination. CONCLUSIONS: The present study determined the dose for further clinical trials of IP PTX to be 80 mg/m2, when combined with a systemic SOX regimen.

Assessment of diagnostic value of fluorescent lymphography-guided lymphadenectomy for gastric cancer.

BACKGROUND: Indocyanine green fluorescent lymphography helps visualize the lymphatic drainage pattern in gastric cancer; however, it is unknown whether fluorescent lymphography visualizes all metastatic lymph nodes. This study aimed to evaluate the sensitivity of fluorescent lymphography to detect metastatic lymph node stations and lymph nodes and the risk of false-negative findings. METHODS: Patients with clinical T1-4a gastric cancer were included. Indocyanine green was peritumorally injected the day prior to surgery by endoscopy. Gastrectomy with systematic D1+ or D2 lymphadenectomy was performed. Stations and lymph nodes were retrieved at the back-table using near-infrared imaging and classified as "fluorescent" or "non-fluorescent" and later matched with histopathological findings. RESULTS: Among 592 patients who underwent minimally invasive gastrectomy from September 2013 until December 2016, lymph node metastases were present in 150. The sensitivity of fluorescent lymphography in detecting all metastatic lymph node stations was 95.3% (143/150 patients), with a false-negative rate of 4.7% (7/150 patients) and the sensitivity in detecting all metastatic lymph nodes was 81.3% (122/150 patients). The negative predictive value was 99.3% for non-fluorescent stations and 99.2% for non-fluorescent LNs. For detecting all metastatic LN stations, subgroup analysis revealed 100% sensitivity for pT1a, 96.8% for pT1b, 100% for pT2, 91.3% for pT3, and 93.6% for pT4a tumors. CONCLUSIONS: Fluorescent lymphography-guided lymphadenectomy can be a useful method for radical lymphadenectomy by facilitating the complete dissection of all potentially positive LN stations. Fluorescent lymphography-guided lymphadenectomy appears to be a reasonable alternative to conventional systematic lymphadenectomy for gastric cancer.

Reduced-port totally robotic distal subtotal gastrectomy for gastric cancer: 100 consecutive cases in comparison with conventional robotic and laparoscopic distal subtotal gastrectomy.

By overcoming technical difficulties with limited access faced when performing reduced-port surgery for gastric cancer, reduced-port totally robotic gastrectomy (RPRDG) could be a safe alternative to conventional minimally invasive gastrectomy. An initial 100 consecutive cases of RPRDG for gastric cancer were performed from February 2016 to September 2018. Short-term outcomes for RPRDG with those for 261 conventional laparoscopic (CLDG) and for 241 robotic procedures (CRDG) over the same period were compared. Learning curve analysis for RPRDG was conducted to determine whether this procedure could be readily performed despite fewer access. During the first 100 cases of RPRDG, no surgeries were converted to open or laparoscopic surgery, and no additional ports were required. RPRDG showed longer operation time than CLDG (188.4 min vs. 166.2 min, p < 0.001) and similar operation time with CRDG (183.1 min, p = 0.315). The blood loss was 35.4 ml for RPRDG, 85.2 ml for CLDG (p < 0.001), and 41.2 ml for CRDG (p = 0.33). The numbers of retrieved lymph nodes were 50.5 for RPRDG, 43.9 for CLDG (p = 0.003), and 55.0 for CRDG (p = 0.055). Postoperative maximum C-reactive protein levels were 96.8 mg/L for RPRDG, 87.8 mg/L for CLDG (p = 0.454), and 81.9 mg/L for CRDG (p = 0.027). Learning curve analysis indicated that the overall operation time of RPRDG stabilized at 180 min after 21 cases. The incidence of major postoperative complications did not differ among groups. RPRDG for gastric cancer is a feasible and safe alternative to conventional minimally invasive surgery. Notwithstanding, this procedure failed to reduce postoperative inflammatory responses.

Delta-shaped gastroduodenostomy using a robotic stapler in reduced-port totally robotic gastrectomy: its safety and efficiency compared with conventional anastomosis techniques.

To investigate the safety and efficiency of using robotic staplers for intracorporeal gastroduodenostomy in reduced-port robotic gastrectomy for gastric adenocarcinoma. We retrospectively reviewed patients who underwent totally robotic and laparoscopic gastrectomy with intracorporeal gastroduodenostomy. Gastroduodenostomy using the ENDOWRIST robotic stapler (RR) was compared to that using an endolinear stapler during robotic gastrectomy (RE) and to that using an endolinear stapler during laparoscopic gastrectomy (LE). A total of 296 patients underwent gastroduodenostomy: 58, 28, and 210 patients with RR, RE, and LE, respectively. There were no conversions to other methods, and all robotic stapling procedures were performed on the console without receiving additional assistance from a bedside surgeon during RR. Comparing the operative outcomes of RR with those of RE and LE, respectively, we noted similar postoperative short-term outcomes. There were no major complications, including anastomosis-related complications, during the postoperative period after RR. The median reconstruction time during RR was 8 min and 45 s, which was similar to that during RE (8 min, 5 s [P > 0.9999]), but longer than that during LE (6 min, 30 s [P < 0.0001]). Intracorporeal gastroduodenostomy using the robotic stapler during robotic gastrectomy could be safely and feasibly performed on the console without the assistance of assistant, bedside surgeons.

Comparison of surgical outcomes between integrated robotic and conventional laparoscopic surgery for distal gastrectomy: a propensity score matching analysis.

This study was aimed to compare the surgical outcomes between conventional laparoscopic distal gastrectomy (CLDG) and integrated robotic distal gastrectomy (IRDG) which used both Single-Site platform and fluorescence image-guided surgery technique simultaneously. Retrospective data of 56 patients who underwent IRDG and 152 patients who underwent CLDG were analyzed. Propensity score matching analysis was performed to control selection bias using age, sex, American Society of Anesthesiologists score, and body mass index. Fifty-one patients were selected for each group. Surgical success was defined as the absence of open conversion, readmission, major complications, positive resection margin, and inadequate lymph node retrieval (<16). Patients characteristics and surgical outcomes of IRDG group were comparable to those of CLDG group, except longer operation time (159.5 vs. 131.7 min; P < 0.001), less blood loss (30.7 vs. 73.3 mL; P = 0.004), higher number of retrieved lymph nodes (LNs) (50.4 vs. 41.9 LNs; P = 0.025), and lower readmission rate (2.0 vs. 15.7%; P = 0.031). Surgical success rate was higher in IRDG group compared to CLDG group (98.0 vs. 82.4%; P = 0.008). In conclusion, this study found that IRDG provides the benefits of higher number of retrieved LNs, less blood loss, and lower readmission rate compared with CLDG in patients with early gastric cancer.

Lower rate of conversion using robotic-assisted surgery compared to laparoscopy in completion total gastrectomy for remnant gastric cancer.

BACKGROUND: Completion total gastrectomy with radical lymphadenectomy for remnant gastric cancer is a technically demanding procedure. No previous studies have compared laparoscopic to robotic-assisted completion gastrectomy, whereas a few small case series have reported benefits of minimally invasive surgery over open surgery. The aim of this study is to assess the effectiveness and feasibility of robotic-assisted compared with laparoscopic completion gastrectomy for the treatment of remnant gastric cancer. METHODS: We retrospectively reviewed data from 55 patients who underwent minimally invasive completion gastrectomy for remnant gastric cancer at the Severance Hospital of Yonsei University Health System from April 2005 to July 2017. Of the 55 patients, 30 patients underwent laparoscopic and 25 underwent robotic-assisted completion total gastrectomy. We compared the patients' demographics, operative outcomes, and postoperative outcomes. RESULTS: Operation time was longer in the robotic-assisted surgery group (225 vs 292 min, P < 0.001), but both groups had similar estimated blood loss. The laparoscopic surgery group had a 13.3% (four patients) rate of conversion to open surgery because of severe adhesions, whereas no patients in the robotic group underwent conversion to laparoscopic or open surgery (P = 0.058). Mean hospital stay, postoperative complications, and recovery were similar in both groups. Pathology results, including the number of retrieved lymph nodes, did not differ between groups. CONCLUSION: Laparoscopic and robotic approaches are both feasible and safe for remnant gastric cancer, with comparable short-term outcomes. However, the robotic approach demonstrated a lower conversion rate than laparoscopy, although the statistical difference was marginal.

Rituximab protects against development of atherosclerotic cardiovascular disease after kidney transplantation: a propensity-matched study.

Recent studies have implicated B cells in atherosclerosis and have verified the atheroprotective effect of rituximab. Rituximab is widely used for desensitization in ABO-incompatible or crossmatch-positive kidney transplantation (KT). Using a single-center KT database, we performed propensity-matched analysis to investigate the association between rituximab and posttransplant atherosclerotic cardiovascular disease (ASCVD). Among 1299 eligible patients, 239 given rituximab induction were matched with 401 controls in a 1:2 propensity score matching process. The cumulative rate of ASCVD during 8 years of follow-up was significantly lower in rituximab-treated patients, compared with matched controls (3.7% vs. 11.2%; P = 0.012). However, all-cause mortality did not differ by group (2.9% vs. 4%; P = 0.943). In multivariable Cox analysis, rituximab proved independently protective of ASCVD (hazard ratio = 0.34, 95% confidence interval: 0.14-0.83). The lower risk of ASCVD seen with rituximab induction reached significance only in patient subsets of diabetes mellitus, pretransplant dialysis, or older age (>50 years). Rituximab induction confers a lower risk of ASCVD during the posttransplant period. This atheroprotective effect appears particularly beneficial in patients whose risk of ASCVD is heightened.

Similar Operative Outcomes between the da Vinci Xi® and da Vinci Si® Systems in Robotic Gastrectomy for Gastric Cancer.

PURPOSE: The robotic system for surgery was introduced to gastric cancer surgery in the early 2000s to overcome the shortcomings of laparoscopic surgery. The more recently introduced da Vinci Xi® system offers benefits allowing four-quadrant access, greater range of motion, and easier docking through an overhead boom rotation with laser targeting. We aimed to identify whether the Xi® system provides actual advantages over the Si® system in gastrectomy for gastric cancer by comparing the operative outcomes. MATERIALS AND METHODS: We retrospectively reviewed all patients who underwent robotic gastrectomy as treatment for gastric cancer from March 2016 to March 2017. Patients' demographic data, perioperative information, and operative and pathological outcomes were collected and analyzed. RESULTS: A total of 109 patients were included in the Xi® group and 179 in the Si® group. Demographic characteristics were similar in both groups. The mean operative time was 229.9 minutes in the Xi® group and 223.7 minutes in the Si® group. The mean estimated blood loss was 72.7 mL in the Xi® group and 62.1 mL in the Si® group. No patient in the Xi® group was converted to open or laparoscopy, while 3 patients in the Si® group were converted, 2 to open surgery and 1 to laparoscopy, this difference was not statistically significant. Bowel function was resumed 3 days after surgery, while soft diet was initiated 4 days after surgery. CONCLUSIONS: We found no difference in surgical outcomes after robotic gastrectomy for gastric cancer between the da Vinci Xi® and da Vinci Si® procedures.

Prognostic Impact of Extended Lymph Node Dissection versus Limited Lymph Node Dissection on pN0 Proximal Advanced Gastric Cancer: a Propensity Score Matching Analysis.

PURPOSE: Splenic hilar lymph node dissection (LND) during total gastrectomy is regarded as the standard treatment for proximal advanced gastric cancer (AGC). This study aimed to investigate whether splenic hilar LND or D2 LND is essential for proximal AGC of pT2-4aN0M0 stage. MATERIALS AND METHODS: Data of curative total gastrectomies (n=370) performed from 2000 to 2010 for proximal AGC of pT2-4aN0 stage were retrospectively reviewed. Clinicopathological characteristics and long-term outcomes were compared using propensity score matching between patients who underwent splenectomy (n=43) and those who did not (n=327) and between patients who underwent D2 LND (n=122) and those who underwent D1+ LND (n=248). RESULTS: Tumors of larger size and a more advanced T stage and significantly lower overall and relapse-free survival (P<0.001) were observed in the splenectomy group than in the 2 spleen-preserving groups. Before propensity score matching, worse overall and relapse-free survival (P<0.001) was observed in the splenectomy group than in the non-splenectomy group. After matching, although the overall survival became similar (P=0.123), relapse-free survival was worse in the splenectomy group (P=0.021). Compared with D1+ LND, D2 LND had no positive impact on the overall (P=0.619) and relapse-free survival (P=0.112) after propensity score matching. CONCLUSIONS: Splenic hilar LND with or without splenectomy may not have an oncological benefit for patients with pathological AGC with no LN metastasis.

Robotic spleen-preserving splenic hilar lymph node dissection during total gastrectomy for gastric cancer.

BACKGROUND: Robotic system may have potential advantages to facilitate the technically challenging splenic hilar lymphadenectomy during gastrectomy for gastric cancer. However, robotic spleen-preserving splenic hilar lymphadenectomy is performed infrequently not only because of the limited availability of the robot but also because of its technical difficulty. In this study, we describe our technique of performing robotic spleen-preserving splenic hilar lymphadenectomy in detail to facilitate wider application and present operative outcomes and the follow-up results of the procedure. METHODS: From 2005 to 2015, 93 patients underwent robotic total gastrectomy with D2 lymphadenectomy. One patient with obvious lymph node (LN) metastasis received splenectomy and was excluded from the analysis. Intraoperative complications, operation and console time, estimated blood loss, postoperative morbidity and mortality, the number of harvested LNs in total and at the splenic hilum, and 5-year overall survival were analyzed, retrospectively. RESULTS: Among the 92 patients, robotic spleen-preserving splenic hilar lymphadenectomy was successfully performed in 91 patients except one who experienced intraoperative splenic artery injury which demanded splenectomy to be performed simultaneously. The overall mean operation time and console time were 287.2 ± 66.0 and 180.2 ± 47.2 min, respectively. Mean estimated blood loss was 141.1 ± 227.0 ml. The mortality was 1.1% (1/92). The overall postoperative morbidity rate was 16.3% (15/92). There was no case of pancreatic fistula, whole splenic infarction, or the delayed aneurysm of splenic artery. The mean numbers of harvested LNs in total and at the splenic hilum were 50.8 ± 18.1 and 1.9 ± 2.6. The 5-year overall survival was 86.3% and 5-year recurrence-free survival was 87.4%. CONCLUSION: This study suggests that robotic application for spleen-preserving splenic hilar lymphadenectomy could be a feasible and safe method.

Single Patient Classifier Assay, Microsatellite Instability, and Epstein-Barr Virus Status Predict Clinical Outcomes in Stage II/III Gastric Cancer: Results from CLASSIC Trial.

PURPOSE: Clinical implications of single patient classifier (SPC) and microsatellite instability (MSI) in stage II/III gastric cancer have been reported. We investigated SPC and the status of MSI and Epstein-Barr virus (EBV) as combinatory biomarkers to predict the prognosis and responsiveness of adjuvant chemotherapy for stage II/III gastric cancer. MATERIALS AND METHODS: Tumor specimens and clinical information were collected from patients enrolled in CLASSIC trial, a randomized controlled study of capecitabine plus oxaliplatin-based adjuvant chemotherapy. The results of nine-gene based SPC assay were classified as prognostication (SPC-prognosis) and prediction of chemotherapy benefit (SPC-prediction). Five quasimonomorphic mononucleotide markers were used to assess tumor MSI status. EBV-encoded small RNA in situ hybridization was performed to define EBV status. RESULTS: There were positive associations among SPC, MSI, and EBV statuses among 586 patients. In multivariate analysis of disease-free survival, SPC-prognosis [hazard ratio (HR): 1.879 (1.101-3.205), 2.399 (1.415-4.067), p=0.003] and MSI status (HR: 0.363, 95% confidence interval: 0.161-0.820, p=0.015) were independent prognostic factors along with age, Lauren classification, TNM stage, and chemotherapy. Patient survival of SPC-prognosis was well stratified regardless of EBV status and in microsatellite stable (MSS) group, but not in MSI-high group. Significant survival benefit from adjuvant chemotherapy was observed by SPC-Prediction in MSS and EBV-negative gastric cancer. CONCLUSION: SPC, MSI, and EBV statuses could be used in combination to predict the prognosis and responsiveness of adjuvant chemotherapy for stage II/III gastric cancer.

Similar hematologic and nutritional outcomes after proximal gastrectomy with double-tract reconstruction in comparison to total gastrectomy for early upper gastric cancer.

BACKGROUND: Proximal gastrectomy offers theoretical benefits over total gastrectomy in terms of hematologic and nutritional outcomes. However, little evidence confirming these benefits has been reported. The aim of this study was to assess the hematologic and nutritional outcomes of proximal gastrectomy with double-tract reconstruction in comparison to those of total gastrectomy. METHODS: We retrospectively analyzed data from 80 patients with stage I gastric cancer who underwent proximal gastrectomy with double-tract reconstruction (n = 38) or total gastrectomy (n = 42) from September 2014 to December 2015. We compared hematologic (including hemoglobin, ferritin, vitamin B12, etc.) and nutritional outcomes [including body mass index (BMI), serum total protein, albumin, total cholesterol, and total lymphocyte count] between the two groups. RESULTS: We found no significant differences in changes in hemoglobin (P = 0.250) or cumulative incidence of iron deficiency anemia (P = 0.971) during a median follow-up period of 24 months (range 18-30 months) after surgery. Cumulative incidence of vitamin B12 deficiency also did not differ significantly between the proximal and total gastrectomy groups (P = 0.087). BMI changes from baseline were not significantly different between the two groups (P = 0.591). Likewise, there were no statistically significant differences in nutritional outcomes. CONCLUSIONS: Proximal gastrectomy with double-tract reconstruction exhibited similar outcomes in terms of hematologic and nutritional features in comparison to total gastrectomy.

Clinical Implications of Microsatellite Instability in Early Gastric Cancer.

PURPOSE: We aimed to evaluate the clinical characteristics of microsatellite instability in early gastric cancer. MATERIALS AND METHODS: The microsatellite instability status of resected early gastric tumors was evaluated using two mononucleotide repeat markers (BAT25 and BAT26) and three dinucleotide repeat markers (D5S346, D2S123, and D17S250). Tumors with instability in two or more markers were defined as microsatellite instability-high (MSI-H) and others were classified as microsatellite stable (MSS). RESULTS: Overall, 1,156 tumors were included in the analysis, with 85 (7.4%) classified as MSI-H compared with MSS tumors. For MSI-H tumors, there was a significant correlation with the female sex, older age, tumor location in the lower gastric body, intestinal histology, lymphovascular invasion (LVI), and submucosal invasion (P<0.05). There was also a trend toward an association with lymph node (LN) metastasis (P=0.056). In mucosal gastric cancer, there was no significant difference in MSI status in tumors with LN metastasis or tumors with LVI. In submucosal gastric cancer, LVI was more frequently observed in MSI-H than in MSS tumors (38.9% vs. 25.0%, P=0.027), but there was no difference in the presence of LN metastases. The prognosis of MSI-H tumors was similar to that of MSS tumors (log-rank test, P=0.797, the hazard ratio for MSI-H was adjusted by age, sex, pT stage, and the number of metastatic LNs, 0.932; 95% confidence interval, 0.423-2.054; P=0.861). CONCLUSIONS: MSI status was not useful in predicting prognosis in early gastric cancer. However, the frequent presence of LVI in early MSI-H gastric cancer may help guide the appropriate treatment for patients, such as endoscopic treatment or limited LN surgical dissection.

Parameters for Predicting Surgical Outcomes for Gastric Cancer Patients: Simple Is Better Than Complex.

BACKGROUND: Various parameters are used to predict perioperative surgical outcomes. However, no comprehensive studies in gastrectomy have been conducted. This study aimed to compare the performance of each parameter in patients with gastric cancer. METHODS: The medical records of 1032 gastric cancer patients who underwent curative gastrectomy between 2009 and 2015 were reviewed. Laboratory values and associated parameters (neutrophil count, lymphocyte count, platelet count, albumin level, Prognostic Nutritional Index, neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, and Systemic Immune-Inflammation Index) as well as body weight-related data and associated parameters [body mass index (BMI), percentage of weight loss, Nutritional Risk Screening 2002 assessment, the Malnutrition Universal Screening Tool, and the Nutritional Risk Index] were measured and calculated. The study end points were major complications, operative mortality, prolonged hospital stay, overall survival (OS), and recurrence-free survival (RFS). RESULTS: Multivariable logistic regression analysis showed that male gender, total gastrectomy, advanced-stage gastric cancer, and low albumin level were risk factors for major complications. Old age, total gastrectomy, advanced-stage cancer, and high BMI were risk factors for operative mortality. Old age, open approach, and total gastrectomy were risk factors for prolonged hospital stay. Multivariable Cox proportional hazards models showed that old age, total gastrectomy, advanced-stage cancer, and high neutrophil count were unfavorable risk factors for OS. Old age, advanced-stage cancer, high neutrophil count, and high BMI were unfavorable risk factors for RFS. CONCLUSIONS: Albumin level, BMI, and neutrophil count are the most useful parameters for predicting short- and long-term surgical outcomes. Compared with complex parameters, simple-to-measure parameters are better for predicting surgical outcomes for gastric cancer patients.

Modification of the TNM Staging System for Stage II/III Gastric Cancer Based on a Prognostic Single Patient Classifier Algorithm.

PURPOSE: The modification of the cancer classification system aimed to improve the classical anatomy-based tumor, node, metastasis (TNM) staging by considering tumor biology, which is associated with patient prognosis, because such information provides additional precision and flexibility. MATERIALS AND METHODS: We previously developed an mRNA expression-based single patient classifier (SPC) algorithm that could predict the prognosis of patients with stage II/III gastric cancer. We also validated its utilization in clinical settings. The prognostic single patient classifier (pSPC) differentiates based on 3 prognostic groups (low-, intermediate-, and high-risk), and these groups were considered as independent prognostic factors along with TNM stages. We evaluated whether the modified TNM staging system based on the pSPC has a better prognostic performance than the TNM 8th edition staging system. The data of 652 patients who underwent gastrectomy with curative intent for gastric cancer between 2000 and 2004 were evaluated. Furthermore, 2 other cohorts (n=307 and 625) from a previous study were assessed. Thus, 1,584 patients were included in the analysis. To modify the TNM staging system, one-grade down-staging was applied to low-risk patients according to the pSPC in the TNM 8th edition staging system; for intermediate- and high-risk groups, the modified TNM and TNM 8th edition staging systems were identical. RESULTS: Among the 1,584 patients, 187 (11.8%), 664 (41.9%), and 733 (46.3%) were classified into the low-, intermediate-, and high-risk groups, respectively, according to the pSPC. pSPC prognoses and survival curves of the overall population were well stratified, and the TNM stage-adjusted hazard ratios of the intermediate- and high-risk groups were 1.96 (95% confidence interval [CI], 1.41-2.72; P<0.001) and 2.54 (95% CI, 1.84-3.50; P<0.001), respectively. Using Harrell's C-index, the prognostic performance of the modified TNM system was evaluated, and the results showed that its prognostic performance was better than that of the TNM 8th edition staging system in terms of overall survival (0.635 vs. 0.620, P<0.001). CONCLUSIONS: The pSPC-modified TNM staging is an alternative staging system for stage II/III gastric cancer.