Molecular and Immune Profiling of Syngeneic Mouse Models Predict Response to Immune Checkpoint Inhibitors in Gastric Cancer / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Appropriate preclinical mouse models are needed to evaluate the response to immunotherapeutic agents. Immunocompetent mouse models have rarely been reported for gastric cancer. Thus, we investigated immunophenotypes and responses to immune checkpoint inhibitor (ICI) in immunocompetent mouse models using various murine gastric cancer cell lines. @*Materials and Methods@#We constructed subcutaneous syngeneic tumors with murine gastric cancer cell lines, YTN3 and YTN16, in C57BL/6J mice. Mice were intraperitoneally treated with IgG isotype control or an anti–programmed death-ligand 1 (PD-L1) neutralizing antibody. We used immunohistochemistry to evaluate the tumor-infiltrating immune cells of formalin-fixed paraffin-embedded mouse tumor tissues. We compared the protein and RNA expression between YTN3 and YTN16 cell lines using a mouse cytokine array and RNA sequencing. @*Results@#The mouse tumors revealed distinct histological and molecular characteristics. YTN16 cells showed upregulation of genes and proteins related to immunosuppression, such as Ccl2 (CCL2) and Csf1 (M-CSF). Macrophages and exhausted T cells were more enriched in YTN16 tumors than in YTN3 tumors. Several YTN3 tumors were completely regressed by the PD-L1 inhibitor, whereas YTN16 tumors were unaffected. Although treatment with a PD-L1 inhibitor increased infiltration of T cells in both the tumors, the proportion of exhausted immune cells did not decrease in the non-responder group. @*Conclusion@#We confirmed the histological and molecular features of cancer cells with various responses to ICI. Our models can be used in preclinical research on ICI resistance mechanisms to enhance clinical efficacy.

What is the role of surgical oncologist in the treatment of gastric cancer?

Surgical oncologist plays a pivotal role in treating patients with cancer in the era of precision medicine. In this article, we summarized traditional roles of surgical oncologists and suggested further additional ones for the modern day in the multidisciplinary approach to gastric cancer treatment.

Does bisphenol-A affect alteration of gut microbiome after bariatric/metabolic surgery?: a comparative metagenomic analysis in a long-term high-fat diet induced-obesity rat model

Purpose@#Bisphenol A (BPA) is a widely used environmental contaminant that is associated with type 2 diabetes mellitus and a shift of gut microbial community. However, little is known about the influence of BPA on gut microbial changes related to bariatric surgery. We investigated whether long-term exposure to dietary BPA causing alterations of gut microbiome occurred after bariatric surgery.  @*Methods@#Six-week-old male Wistar rats were fed either a high- fat diet (HFD) or HFD + BPA for 40 weeks. Then sleeve gastrectomy (SG) or Roux-en Y gastric bypass (RYGB) was performed in each diet group and observed for 12 weeks postoperatively. Fecal samples were collected at the 40th weeks and 12th postoperative weeks. Using 16S ribosomal RNA gene sequencing analysis on fecal samples, a comparative metagenomic analysis on gut microbiome composition was performed.  @*Results@#Long-term exposure to HFD with BPA showed higher body weight change and higher level of fasting blood sugar after 40 weeks-diet challenge than those of the HFD only group. After bariatric surgeries, mean body weight of the HFD with BPA group was significantly higher than the HFD only group, but there was no difference between the SG and RYGB groups. The metagenomic analyses demonstrated that long-term exposure to dietary BPA did not affect significant alterations of gut microbiome before and after bariatric surgery, compared with the HFD groups.  @*Conclusion@#Our results highlighted that BPA was a risk factor for obesity and may contribute to glucose intolerance, but it did not affect alterations of gut microbiome after bariatric/metabolic surgery.

Risk Factors for the Severity of Complications in Minimally Invasive Total Gastrectomy for Gastric Cancer: a Retrospective Cohort Study

Purpose@#Minimally invasive gastrectomy is a promising surgical method with well-known benefits, including reduced postoperative complications. However, for total gastrectomy of gastric cancers, this approach does not significantly reduce the risk of complications. Therefore, we aimed to evaluate the incidence and risk factors for the severity of complications associated with minimally invasive total gastrectomy for gastric cancer. @*Materials and Methods@#The study included 392 consecutive patients with gastric cancer who underwent either laparoscopic or robotic total gastrectomy between 2011 and 2019.Clinicopathological and operative characteristics were assessed to determine the features related to postoperative complications after minimally invasive total gastrectomy. Binomial and multinomial logistic regression models were used to identify the risk factors for overall complications and mild and severe complications, respectively. @*Results@#Of 103 (26.3%) patients experiencing complications, 66 (16.8%) and 37 (9.4%) developed mild and severe complications, respectively. On multivariate multinomial regression analysis, independent predictors of severe complications included obesity (OR, 2.56; 95% CI, 1.02−6.43; P=0.046), advanced stage (OR, 2.90; 95% CI, 1.13−7.43; P=0.026), and more intraoperative bleeding (OR, 1.04; 95% CI, 1.02−1.06; P=0.001). Operation time was the only independent risk factor for mild complications (OR, 1.06; 95% CI, 1.001−1.13; P=0.047). @*Conclusions@#The risk factors for mild and severe complications were associated with surgery, indicating surgical difficulty. Surgeons should be aware of these potential risks that are related to the severity of complications so as to reduce surgery-related complications after minimally invasive total gastrectomy for gastric cancer.

Bariatric surgery versus medical therapy in Korean obese patients: prospective multicenter nonrandomized controlled trial (KOBESS trial)

Purpose@#The aim of this study was to show that bariatric surgery (BS) is more effective than medical therapy (MT) in Asian obese patients. @*Methods@#In this prospective, multicenter, nonrandomized, controlled trial, obese patients with body mass index of ≥35 kg/m2 or 30.0–34.9 kg/m2 with obesity-related comorbidities were assigned to undergo BS, such as laparoscopic sleeve gastrectomy and Roux-en-Y gastric bypass, or MT. Patients who underwent BS were evaluated 4, 12, 24, and 48 weeks after surgery, whereas patients who received MT were monitored at a hospital every 6 weeks for 1 year. At each visit, weight, waist and hip circumference, and blood pressure were measured, and patients underwent physical examination and laboratory testing. Health-related quality of life (HQOL) was investigated using Euro QOL-5 Dimension, Impact of Weight on Quality of Life questionnaire-Lite and Obesity-related Problems scale. @*Results@#The study included 264 patients from 13 institutions; of these, 64 underwent BS and 200 received MT. Of the patients who underwent BS, 6.3% experienced early complications. Relative weight changes from baseline to 48 weeks were significantly greater in the BS than in the MT group (26.9% vs. 2.1%, P < 0.001), as were the rates of remission of diabetes (47.8% vs. 16.7%, P = 0.014), hypertension (60.0% vs. 26.1%, P < 0.001), and dyslipidemia (63.2% vs. 22.0%, P < 0.001). HQOL was better in the BS than in the MT group at 48 weeks. @*Conclusion@#BS was safe and effective in Korean obese patients, with greater weight reduction, remission of comorbidities, and quality of life improvement than MT.

Articulating laparoscopic instruments: are they a breakthrough that can overcome current limitations in laparoscopic gastric cancer surgery?

Laparoscopic surgery is rapidly evolving with technological advances, but there are several drawbacks. An articulating device, with freedom of a perfect 360°, is attractive as a solution to overcome the restriction of instrument movement caused by straight tools. Its usefulness or efficacy should be supported by relevant scientific evidence. However, it is sometimes difficult to prove it because the factors influencing the surgical outcomes are complex and closely related to each other.

Omental Free-Shaped Flap Reinforcement on the Anastomosis and Dissected Area (OFFROAD) Following Reconstruction after Gastrectomy: A Retrospective Case-Control Study

The recent advancements in surgical techniques and perioperative care have improved postoperative morbidity and survival after gastric cancer surgeries. However, anastomotic leakage, the most serious complication post-gastrectomy, continues to occur. In esophageal and colorectal cancer surgeries, the omentum is used as a physical barrier and increases blood perfusion to prevent leakage to the anastomotic site. However, the use of the omentum as an anastomotic barrier after gastrectomy has not been reported yet. The authors aimed to evaluate the efficacy and safety of omental free-shaped flap reinforcement on the anastomosis and dissected area following reconstruction after gastrectomy for preventing and treating anastomotic leakage. They reported that omental free-shaped flap reinforcement on the anastomosis might prevent anastomotic leakage post-gastrectomy. The omental flap also prevented further deterioration when leakage occurred. However, anastomosis-related complications, such as anastomotic stenosis and delayed gastric emptying, after an omental patch technique need to be evaluated further.

The pattern of postoperative quality of life following minimally invasive gastrectomy for gastric cancer: a prospective cohort from Korean multicenter robotic gastrectomy trial

Purpose@#Quality of life (QOL) has become important in the trend of emphasizing patient satisfaction. This study aimed to evaluate the QOL in patients who underwent laparoscopic or robotic gastrectomy for gastric cancer. @*Methods@#A prospective trial was performed involving patients who underwent laparoscopic or robotic gastrectomy for primary gastric cancer at 11 hospitals in Korea. Within this comparative trial, QOL, postoperative pain, and long-term complications were exanimated. The quality-of-life questionnaire (QLQ)-C30 and QLQ-STO22 developed by the European Organization for Research and Treatment of Cancer were used for the QOL survey. We compared the data after dividing it into several types of characteristics as follows; device (robotic or laparoscopic), operation type, pathological stage, and sex.Biased components were extracted by logistic regression analysis. Propensity score matching was applied to the data set with the biased components. @*Results@#In total, 434 patients (211 for laparoscopic surgery and 223 for robotic surgery) were enrolled, out of which 321 patients who responded to both preoperative and postoperative surveys were selected for analysis. Robotic gastrectomy was not different from laparoscopic gastrectomy with respect to postoperative QOL. Distal gastrectomy showed better scores than total gastrectomy in terms of role functioning, social functioning, fatigue, nausea/vomiting, pain, dyspnea, constipation, financial difficulties, dysphagia, eating restrictions, anxiety, taste, and body image. Male patients showed better scores on the 19 scales compared to female patients. @*Conclusion@#Robotic and laparoscopic approaches for gastric cancer surgery did not differ from each other with respect to QOL. Distal gastrectomy resulted in better QOL than total gastrectomy.

Multicenter Prospective Study of Laparoscopic Nissen Fundoplication for Gastroesophageal Reflux Disease in Korea

BACKGROUNDS/AIMS: This multicenter study aims to evaluate the effect and feasibility of anti-reflux surgery compared with medical treatment for gastroesophageal reflux disease (GERD). METHODS: Patients with GERD who were undergoing medical treatment with proton pump inhibitors for more than 8 weeks and those who were scheduled to undergo anti-reflux surgery were enrolled. Efficacy of pre-operative medical treatment was evaluated retrospectively and effect of anti-reflux surgery was prospectively evaluated at 1 week and 3 months after surgery. Quality of life (QOL) was also investigated before and after surgery. RESULTS: Between February and October 2018, 51 patients underwent laparoscopic Nissen fundoplication for treating GERD at 5 hospitals in Korea. Thirty-four patients (66.7%) showed poor proton pump inhibitor response. At 3 months after surgery, heartburn was completely resolved in 87.9% patients and partially improved in 9.1%. Acid regurgitation was completely resolved in 82.9% and partially improved in 11.4%. Atypical extraesophageal symptoms were completely controlled in 45.5% and partially controlled in 36.4%. GERD-related QOL scores at 1 week after surgery significantly improved compared with pre-operative scores. There was no difference in GERD-related QOL scores between 1 week and 3 months after surgery. General QOL measured with European QOL-5 dimensions and health-related QOL instrument with 8 items significantly improved after anti-reflux surgery. Satisfaction with treatment was significantly higher after surgery than before surgery (72.5% vs 11.8%, P < 0.001). CONCLUSION: Anti-reflux surgery improved GERD symptoms and QOL in patients. Anti-reflux surgery is an effective treatment option compared with medical treatment for GERD patients selected for surgical treatment.

Feasibility of Linear-Shaped Gastroduodenostomy during the Performance of Totally Robotic Distal Gastrectomy

PURPOSE: Although linear-shaped gastroduodenostomy (LSGD) was reported to be a feasible and reliable method of Billroth I anastomosis in patients undergoing totally laparoscopic distal gastrectomy (TLDG), the feasibility of LSGD for patients undergoing totally robotic distal gastrectomy (TRDG) has not been determined. This study compared the feasibility of LSGD in patients undergoing TRDG and TLDG.MATERIALS AND METHODS: ALL C: onsecutive patients who underwent LSGD after distal gastrectomy for gastric cancer between January 2009 and December 2017 were analyzed retrospectively. Propensity score matching (PSM) analysis was performed to reduce the selection bias between TRDG and TLDG. Short-term outcomes, functional outcomes, learning curve, and risk factors for postoperative complications were analyzed.RESULTS: This analysis included 414 patients, of whom 275 underwent laparoscopy and 139 underwent robotic surgery. PSM analysis showed that operation time was significantly longer (163.5 vs. 132.1 minutes, P<0.001) and postoperative hospital stay significantly shorter (6.2 vs. 7.5 days, P<0.003) in patients who underwent TRDG than in patients who underwent TLDG. Operation time was the independent risk factor for LSGD after intracorporeal gastroduodenostomy. Cumulative sum analysis showed no definitive turning point in the TRDG learning curve. Long-term endoscopic findings revealed similar results in the two groups, but bile reflux at 5 years showed significantly better improvement in the TLDG group than in the TRDG group (P=0.016).CONCLUSIONS: LSGD is feasible in TRDG, with short-term and long-term outcomes comparable to that in TLDG. LSGD may be a good option for intracorporeal Billroth I anastomosis in patients undergoing TRDG.

2014–2017 Nationwide Bariatric and Metabolic Surgery Report in Korea

PURPOSE: The information committee of the Korean Society for Metabolic and Bariatric Surgery (KSMBS) performed the nationwide survey of bariatric and metabolic operations to report IFSO (International Federation for the Surgery of Obesity and Metabolic Disorders) worldwide survey annually. This study aimed to report the trends of bariatric and metabolic surgery in Korea in 2014–2017. MATERIALS AND METHODS: We analyzed the accumulated nationwide survey data conducted for annual ISFO survey from 2014 to 2017. Trends such as the number of operations by hospital type and the number of operations by surgical method were analyzed. RESULTS: The number of operations has decreased sharply in 2015 comparing to 2014 (913⇒550). The number of operations performed in private hospitals dropped sharply from 529 to 250, 198, and 103 cases. The number of revisional surgeries increased to 223 in 2015. The primary surgery number fell from 757 in 2014 to 327 in 2015. In primary surgery, sleeve gastrectomy was gradually increased from 2014 to 143 (18.9%), 105 (32.1%), 167 (47.2%) and 200 (56.3%) and became the most frequently performed surgery. On the other hand, the incidence of adjustable gastric band decreased gradually from 439 (58.0%) to 117 (35.8%), 112 (31.6%) and 59 (16.6%). CONCLUSION: The overall number of obesity metabolic operations has decreased since 2014, especially the number of adjustable gastric band, and the number of operations in private hospitals declined sharply. On the other hand, the number of operations in university hospitals did not change much, and the number of sleeve gastrectomy increased.

Nationwide survey of partial fundoplication in Korea: comparison with total fundoplication

PURPOSE: Laparoscopic total fundoplication is the standard surgery for gastroesophageal reflux disease. However, partial fundoplication may be a viable alternative. Here, we conducted a nationwide survey of partial fundoplication in Korea. METHODS: The Korean Anti-Reflux Surgery study group recorded 32 cases of partial fundoplication at eight hospitals between September 2009 and January 2016. The surgical outcomes and postoperative adverse symptoms in these cases were evaluated and compared with 86 cases of total fundoplication. RESULTS: Anterior partial fundoplication was performed in 20 cases (62.5%) and posterior in 12 (37.5%). In most cases, partial fundoplication was a secondary procedure after operations for other conditions. Half of patients who underwent partial fundoplication had typical symptoms at the time of initial diagnosis, and most of them showed excellent (68.8%), good (25.0%), or fair (6.3%) symptom resolution at discharge. Compared to total fundoplication, partial fundoplication showed no difference in the resolution rate of typical and atypical symptoms. However, adverse symptoms such as dysphagia, difficult belching, gas bloating and flatulence were less common after partial fundoplication. CONCLUSION: Although antireflux surgery is not popular in Korea and total fundoplication is the primary surgical choice for gastroesophageal reflux disease, partial fundoplication may be useful in certain conditions because it has less postoperative adverse symptoms but similar efficacy to total fundoplication.

Safety of Laparoscopic Sentinel Basin Dissection in Patients with Gastric Cancer: an Analysis from the SENORITA Prospective Multicenter Quality Control Trial

PURPOSE: We investigated complications after laparoscopic sentinel basin dissection (SBD) for patients with gastric cancer who were enrolled in a quality control study, prior to the phase III trial of sentinel lymph node navigation surgery (SNNS). MATERIALS AND METHODS: We analyzed prospective data from a Korean multicenter prerequisite quality control trial of laparoscopic SBD for gastric cancer and assessed procedure-related and surgical complications. All complications were classified according to the Clavien-Dindo Classification (CDC) system and were compared with the results of the previously published SNNS trial. RESULTS: Among the 108 eligible patients who were enrolled in the quality control trial, 8 (7.4%) experienced complications during the early postoperative period. One patient with gastric resection-related duodenal stump leakage recovered after percutaneous drainage (grade IIIa in CDC). The other postoperative complications were mild and patients recovered with supportive care. No complications were directly related to the laparoscopic SBD procedure or tracer usage, and there were no mortalities. The laparoscopic SBD complication rates and patterns that were observed in this study were comparable to those of a previously reported trial. CONCLUSIONS: The results of our prospective, multicenter quality control trial demonstrate that laparoscopic SBD is a safe procedure during SNNS for gastric cancer.

A Novel Roux-en-Y Reconstruction Involving the Use of Two Circular Staplers after Distal Subtotal Gastrectomy for Gastric Cancer

PURPOSE: Although Roux-en-Y (R-Y) reconstruction after distal gastrectomy has several advantages, such as prevention of bile reflux into the remnant stomach, it is rarely used because of the technical difficulty. This prospective randomized clinical trial aimed to show the efficacy of a novel method of R-Y reconstruction involving the use of 2 circular staplers by comparing this novel method to Billroth-I (B-I) reconstruction. MATERIALS AND METHODS: A total of 118 patients were randomly allocated into the R-Y (59 patients) and B-I reconstruction (59 patients) groups. R-Y anastomosis was performed using two circular staplers and no hand sewing. The primary end-point of this clinical trial was the reflux of bile into the remnant stomach evaluated using endoscopic and histological findings at 6 months after surgery. RESULTS: No significant differences in clinicopathological findings were observed between the 2 groups. Although anastomosis time was significantly longer for the patients of the R-Y group (P<0.001), no difference was detected between the 2 groups in terms of the total surgery duration (P=0.112). Endoscopic findings showed a significant reduction of bile reflux in the remnant stomach in the R-Y group (P<0.001), and the histological findings showed that reflux gastritis was more significant in the B-I group than in the R-Y group (P=0.026). CONCLUSIONS: The results of this randomized controlled clinical trial showed that compared with B-I reconstruction, R-Y reconstruction using circular staplers is a safe and feasible procedure. This clinical trial study was registered at www.ClinicalTrials.gov (registration No. NCT01142271).

Real-time Vessel Navigation Using Indocyanine Green Fluorescence during Robotic or Laparoscopic Gastrectomy for Gastric Cancer

PURPOSE: Identification of the infrapyloric artery (IPA) type is a key component of pylorus-preserving gastrectomy. As the indocyanine green (ICG) fluorescence technique is known to help visualize blood vessels and flow during reconstruction, we speculated that this emerging technique would be helpful in identifying the IPA type. MATERIALS AND METHODS: From August 2015 to February 2016, 20 patients who underwent robotic or laparoscopic gastrectomy were prospectively enrolled. After intravenous injection of approximately 3 mL of ICG (2.5 mg/mL), a near-infrared fluorescence apparatus was applied. The identified shape of the IPA was confirmed by examining the actual anatomy following infrapyloric dissection. RESULTS: The mean interval time between ICG injection and visualization of the artery was 22.2 seconds (range, 14–30 seconds), and the mean duration of the arterial phase was 16.1 seconds (range, 9–30 seconds). The overall positive predictive value (PPV) of ICG fluorescence in identifying the IPA type was 80% (16/20). The IPA type was incorrectly predicted in four patients, all of whom were obese with a body mass index (BMI) of more than 25 kg/m². CONCLUSIONS: Our preliminary results indicate that intraoperative vascular imaging using the ICG fluorescence technique may be helpful for robotic or laparoscopic pylorus-preserving gastrectomy.

Case Report of an Adult Patient Who Underwent a Serial Transverse Enteroplasty Procedure for Short Bowel Syndrome Following an Esophagectomy and Total Gastrectomy

Since its introduction as an alternative intestinal lengthening technique, the serial transverse enteroplasty (STEP) procedure has been used increasingly as the surgical treatment of choice for children with short bowel syndrome (SBS). On the other hand, there are few report of its efficacy in adults with SBS, particularly those who have previously undergone a gastrectomy. This case report describes a 34-year-old woman with a short bowel after an esophagectomy and total gastrectomy due to lye ingestion followed by an extensive intestinal resection due to small bowel strangulation. The STEP procedure was performed successfully and the small intestine was lengthened from 55 to 75 cm. The patient tolerated the procedure well and was weaned off total parenteral nutrition. The frequency and characteristics of diarrhea improved, and her weight remained acceptable via management with intermittent parenteral nutritional support for 6 months postoperatively. This case suggests that the STEP procedure should be considered for gastrectomized patients with SBS.

Antireflux Surgery in Korea: A Nationwide Study from 2011 to 2014

BACKGROUND/AIMS: Although laparoscopic fundoplication is a well-established therapy for gastroesophageal reflux disease (GERD) in Western countries, the mainstay of GERD treatment in Korea is long-term proton pump inhibitor (PPI) use. The aim of the present study was to evaluate nationwide data regarding antireflux surgery in Korea. METHODS: Data from 2011 to 2014 were collected from the Korean Antireflux Surgery Study Group and then analyzed. RESULTS: A total of 87 patients underwent laparoscopic fundoplication for the treatment of GERD. Preoperatively, typical symptoms were present in 81 patients (93%) and atypical symptoms were present in 51 patients (59%). Twenty-seven patients (31%) had poor PPI responses. The average surgical time and postoperative hospital stay were 116.3±42.3 minutes and 4.3±3.1 days, respectively. At 3 months after surgery, typical symptoms were completely controlled in 86.3% of patients and partially controlled in 11.7%, whereas atypical symptoms were completely controlled in 63.3% of patients and partially controlled in 23.3%. CONCLUSIONS: This study showed that although atypical symptoms and PPI nonresponders are common, the complete control rates of typical and atypical symptoms were 86.3% and 63.3%, respectively. Laparoscopic fundoplication is an efficacious method of controlling the symptoms of GERD and has an acceptable rate of postoperative morbidity and adverse symptoms.

Can Robotic Gastrectomy Surpass Laparoscopic Gastrectomy by Acquiring Long-Term Experience? A Propensity Score Analysis of a 7-Year Experience at a Single Institution

PURPOSE: It is hypothesized that robotic gastrectomy may surpass laparoscopic gastrectomy after the operators acquire long-term experience and skills in the manipulation of robotic arms. This study aimed to evaluate the long-term learning curve of robotic distal gastrectomy (RDG) for gastric cancer compared with laparoscopic distal gastrectomy (LDG). MATERIALS AND METHODS: From October 2008 to December 2015, patients who underwent LDG (n=809) were matched to patients who underwent RDG (n=232) at a 1:1 ratio, by using a propensity score matching method after stratification for the operative year. The surgical outcomes, such as trends of operative time, blood loss, and complication rate, were compared between the two groups. RESULTS: The RDG group showed a longer operative time (171.3 minutes vs. 147.6 minutes, P<0.001) but less estimated blood loss (77.6 ml vs. 116.6 ml, P<0.001). The complication rate and postoperative recovery did not differ between the two groups. The RDG group showed a longer operative time and similar estimated blood loss compared with the LDG group after 5 years of experience (operative time: 159.2 minutes vs. 136.0 minutes in 2015, P=0.003; estimated blood loss: 72.9 ml vs. 78.1 ml in 2015, P=0.793). CONCLUSIONS: In terms of short-term surgical outcomes, RDG may not surpass LDG after a long-term experience with the technique.

Is There any Role of Visceral Fat Area for Predicting Difficulty of Laparoscopic Gastrectomy for Gastric Cancer?

PURPOSE: Obesity is associated with morbidity following gastric cancer surgery, but whether obesity influences morbidity after laparoscopic gastrectomy (LG) remains controversial. The present study evaluated whether body mass index (BMI) and visceral fat area (VFA) predict postoperative complications. MATERIALS AND METHODS: A total of 217 consecutive patients who had undergone LG for gastric cancer between May 2003 and December 2005 were included in the present study. We divided the patients into two groups ('before learning curve' and 'after learning curve') based on the learning curve effect of the surgeon. Each of these groups was sub-classified according to BMI ( or =25 kg/m2) and VFA ( or =100 cm2). Surgical outcomes, including operative time, quantity of blood loss, and postoperative complications, were compared between BMI and VFA subgroups. RESULTS: The mean operative time, length of hospital stay, and complication rate were significantly higher in the before learning curve group than in the after learning curve group. In the subgroup analysis, complication rate and length of hospital stay did not differ according to BMI or VFA; however, for the before learning curve group, mean operative time and blood loss were significantly higher in the high VFA subgroup than in the low VFA subgroup (P=0.047 and P=0.028, respectively). CONCLUSIONS: VFA may be a better predictive marker than BMI for selecting candidates for LG, which may help to get a better surgical outcome for inexperienced surgeons.

Effects of Continuing Adjuvant S-1 for 1 Year on the Prognosis of Gastric Cancer Patients: Results from a Prospective Single Center Study

PURPOSE: Although several clinical trials have proven the efficacy of adjuvant S-1 treatment in gastric cancers, it is still unclear which patients receive the most benefit. In this study, we prospectively recruited patients with locally advanced gastric cancer who had undergone curative resection followed by adjuvant S-1 administration to investigate which factors affect the outcomes. MATERIALS AND METHODS: Between July 2010 and October 2011, we enrolled 49 patients who underwent curative resection for stage II or III gastric cancer and who subsequently received adjuvant S-1 treatment for 1 year. RESULTS: Twenty-nine patients (59.2%) continued S-1 treatment for 1 year, and 12 patients (24.5%) experienced recurrent disease during the follow-up period. Patients with continuation of S-1 for 1 year had significantly increased rates of disease-free survival (P<0.001) and overall survival (P=0.001) relative to the patients who discontinued S-1 during year 1. Multivariate analysis indicated poor outcomes for patients with stage III disease and those who discontinued S-1 treatment. Excluding patients who discontinued S-1 due to cancer progression (n=7), adjuvant treatment with S-1 still demonstrated a significant difference in the disease-free survival rate between the patients who continued treatment and those who discontinued it (P=0.020). CONCLUSIONS: S-1 is tolerated as adjuvant treatment in gastric cancer patients. However, discontinuing S-1 treatment may be an unfavorable factor in the prevention of recurrence. S-1 adjuvant treatment should be continued for 1 year if possible through the proper management of toxicities.