Outcomes of minimally invasive surgery for early gastric cancer are comparable with those for open surgery: analysis of 1,013 minimally invasive surgeries at a single institution

Effects of Clavien-Dindo Classification on Long-Term Survival of Patients With Advanced Gastric Cancer After Radical Resection: A Propensity Score-matched Study

BACKGROUND

The impact of postoperative complications (POCs) classified by the Clavien-Dindo (C-D) system on long-term survival after radical resection in patients with advanced gastric cancer (AGC) is not yet clear.

METHODS

This study analyzed 531 patients with AGC who underwent radical resection in an institution between January 2015 and December 2017. Patients were divided into 2 groups according to the occurrence of POCs and recorded according to C-D classifications. The long-term survival outcomes of the entire cohort after propensity score matching (PSM) were compared.

RESULTS

After PSM, there was no significant difference in baseline data between the complications (C) group (n = 92) and the non-complications (NC) group (n = 92). Survival analysis showed that the 5-year overall survival (OS) and relapse-free survival (RFS) were lower in the C group (48.9% vs 62.0%, P = .040; 38.5% vs 54.9%, P = .005; respectively). Subgroup analysis showed that severe complications (C-D grade > II) were associated with a decrease in 5-year OS and RFS compared with the matched NC group (40.0% vs 62.0%, P = .008; 29.4% vs 54.9%, P = .001; respectively). Multivariate analysis confirmed adjuvant chemotherapy, tumor size, and complications were independent risk factors for poor survival outcomes. Further multivariate analysis showed that older age, combined excision, and comorbidities were independent risk factors for POCs.

CONCLUSIONS

Severe complications reduced the survival outcome of patients. More attention should be paid to perioperative management of patients with high risk factors for complications.

The Multidisciplinary Approach and Surgical Management of GE Junction Adenocarcinoma

Gastroesophageal (GE) junction adenocarcinoma is an aggressive malignancy of growing incidence and is associated with public health issues such as obesity and GERD. Management has evolved over the last two decades to incorporate a multidisciplinary approach, including endoscopic intervention, neoadjuvant chemotherapy/chemoradiation, and minimally invasive or more limited surgical approaches. Surgical approaches include esophagectomy, total gastrectomy, and, more recently, proximal gastrectomy. This review analyzes the evidence for and applicability of these varied approaches in management, as well as areas of continued controversy and investigation.

Development and validation of a predictive model combining clinical, radiomics, and deep transfer learning features for lymph node metastasis in early gastric cancer

Background

This study aims to develop and validate a predictive model combining deep transfer learning, radiomics, and clinical features for lymph node metastasis (LNM) in early gastric cancer (EGC).

Materials and methods

This study retrospectively collected 555 patients with EGC, and randomly divided them into two cohorts with a ratio of 7:3 (training cohort, n = 388; internal validation cohort, n = 167). A total of 79 patients with EGC collected from the Second Affiliated Hospital of Soochow University were used as external validation cohort. Pre-trained deep learning networks were used to extract deep transfer learning (DTL) features, and radiomics features were extracted based on hand-crafted features. We employed the Spearman rank correlation test and least absolute shrinkage and selection operator regression for feature selection from the combined features of clinical, radiomics, and DTL features, and then, machine learning classification models including support vector machine, K-nearest neighbor, random decision forests (RF), and XGBoost were trained, and their performance by determining the area under the curve (AUC) were compared.

Results

We constructed eight pre-trained transfer learning networks and extracted DTL features, respectively. The results showed that 1,048 DTL features extracted based on the pre-trained Resnet152 network combined in the predictive model had the best performance in discriminating the LNM status of EGC, with an AUC of 0.901 (95% CI: 0.847-0.956) and 0.915 (95% CI: 0.850-0.981) in the internal validation and external validation cohorts, respectively.

Conclusion

We first utilized comprehensive multidimensional data based on deep transfer learning, radiomics, and clinical features with a good predictive ability for discriminating the LNM status in EGC, which could provide favorable information when choosing therapy options for individuals with EGC.

Application of Machine Learning Algorithms to Predict Lymph Node Metastasis in Early Gastric Cancer

OBJECTIVE

This study aimed to establish the best early gastric cancer lymph node metastasis (LNM) prediction model through machine learning (ML) to better guide clinical diagnosis and treatment decisions.

METHODS

We screened gastric cancer patients with T1a and T1b stages from 2010 to 2015 in the Surveillance, Epidemiology and End Results (SEER) database and collected the clinicopathological data of patients with early gastric cancer who were treated with surgery at the Second Affiliated Hospital of Nanchang University from January 2014 to December 2016. At the same time, we applied 7 ML algorithms-the generalized linear model (GLM), RPART, random forest (RF), gradient boosting machine (GBM), support vector machine (SVM), regularized dual averaging (RDA), and the neural network (NNET)-and combined them with patient pathological information to develop the best prediction model for early gastric cancer lymph node metastasis. Among the SEER set, 80% were randomly selected to train the models, while the remaining 20% were used for testing. The data from the Second Affiliated Hospital were considered as the external verification set. Finally, we used the AUROC, F1-score value, sensitivity, and specificity to evaluate the performance of the model.

RESULTS

The tumour size, tumour grade, and depth of tumour invasion were independent risk factors for early gastric cancer LNM. Comprehensive comparison of the prediction model performance of the training set and test set showed that the RDA model had the best prediction performance (F1-score = 0.773; AUROC = 0.742). The AUROC of the external validation set was 0.73.

CONCLUSIONS

Tumour size, tumour grade, and depth of tumour invasion were independent risk factors for early gastric cancer LNM. ML predicted LNM risk more accurately, and the RDA model had the best predictive performance and could better guide clinical diagnosis and treatment decisions.

A nomogram to predict risk of lymph node metastasis in early gastric cancer

Lymph node (LN) metastasis is known as one of the most important prognostic factors for early gastric cancer (EGC) patients. Patients without LNM normally have better prognosis. However, there is no evaluation criteria to accurately assess the possibility of LN metastasis. Therefore, this study aims to establish an effective nomogram for prognosis prediction. In this study, 285 EGC patients from January 2010 to December 2015 were enrolled. Pearson's Chi-Square (χ2) test (including continuity correction when appropriate) and logistics regression analyses was used to identify the risk factors for LN metastasis. The independent risk factors identified were then incorporated in a nomogram model. The predictive accuracy and discriminative ability of the nomogram were evaluated by receiver operating characteristic curve (ROC) and calibration curve. LN metastasis occurred in 59 (20.7%) EGC patients. And most of these patients were submucosal cancers (48/59). Chi-square test indicated lymphovascular emboli, carbohydrate antigen 19-9 (CA19-9), ulcer, tumor size, tumor infiltration and histological grade were the risk factors, and multivariate logistics analyses confirmed all these six factors were independent risk factors of LN metastasis, which were selected to construct the nomogram. The nomogram proved well calibrated and had good discriminative ability (C-index value: 0.842). The proposed nomogram could result in more-accurate risk prediction for EGC patients.

Safety of Ligation of Aberrant Left Hepatic Artery Originating from Left Gastric Artery in Laparoscopic Gastrectomy for Gastric Cancer

There are still lot of controversies whether aberrant left hepatic artery (ALHA) originating from left gastric artery should be ligated or preserved during gastric cancer (GC) surgery. We aimed to investigate this issue. We reviewed ALHA cases who had laparoscopic gastrectomy for gastric cancer at Seoul National University Hospital (SNUH) from 2012 to 2016. Type of ALHA variants using Michel's classification of hepatic arterial anatomy and diameter of each vessel were evaluated by 2 radiologists. Postoperative hepatic function and surgical outcome were collected until 6 months after surgery. Results showed that if the diameter of ALHA was larger than 1.5 mm, a transient elevation of SGOT and SGPT on postoperative day 2 was observed in the ligated cases. No differences were observed in operation time, amount of blood loss, overall complication rate, hospital stay, and number of lymph nodes retrieved between the ligated and preserved replaced left hepatic artery (RLHA) and accessory left hepatic artery (acLHA) group. In this study, we conclude that ligation of ALHA seems to be safe as none of the patients suffered adverse outcome. A transient rise in postoperative SGOT and SGPT levels were seen after ligating ALHA >1.5 mm in diameter regardless of subtype.

Impact of minimally invasive gastrectomy on use of and time to adjuvant chemotherapy for gastric adenocarcinoma

BACKGROUND

Chemotherapy improves outcomes in patients with resectable gastric cancer. Minimally invasive gastrectomy (MIS) rates are increasing, though the impact of MIS on postoperative chemotherapy remains uncertain. This study examines the impact of MIS vs open gastrectomy (OG) on utilization of adjuvant chemotherapy for high-risk gastric cancer.

METHODS

Patients in the National Cancer Database who underwent resection for high-risk gastric adenocarcinoma between 2010 and 2015 were included. Patients were stratified by surgical approach (MIS vs OG) and analyzed using multivariable regression modeling. Primary endpoints were utilization of and time to initiation of adjuvant chemotherapy.

RESULTS

Overall, 23 071 patients were included; 16 595 (71.9%) underwent OG and 6476 (28.1%) underwent MIS. After adjusting for patient and tumor characteristics, MIS was not associated with increased use of adjuvant chemotherapy (odds ratio [OR]: 1.027, 95% confidence interval [CI]: 0.95 to 1.11, P = .50), and time to initiation of chemotherapy was similar (-2% change, 95% CI: -5% to +1%, P = .27). MIS was associated with shorter hospital stays (-1 day). Thirty-day readmission rates, 90-day mortality, and overall survival were similar between groups.

CONCLUSIONS

In this study, while MIS for gastric adenocarcinoma was associated with shorter hospital stays and comparable survival, it was not associated with improved utilization or time to initiation of adjuvant chemotherapy.

Short-term Outcomes of a Multicenter Randomized Controlled Trial Comparing Laparoscopic Distal Gastrectomy With D2 Lymphadenectomy to Open Distal Gastrectomy for Locally Advanced Gastric Cancer (KLASS-02-RCT)

OBJECTIVE

The aim of the study was to evaluate the short-term outcomes of KLASS-02-RCT, a multicenter randomized controlled trial comparing laparoscopic distal gastrectomy (LDG) with D2 lymphadenectomy with open distal gastrectomy (ODG).

SUMMARY BACKGROUND DATA

Although several benefits of laparoscopic gastric cancer surgery have been reported, strong evidence is still limited, especially in locally advanced gastric cancer which requires extensive lymph node dissection.

METHODS

Enrollment criteria included histologically confirmed cT2-4a and N0-1 gastric adenocarcinoma. Thirty-day morbidity, 90-day mortality, postoperative pain, and recovery were compared between LDG and ODG groups.

RESULTS

A total of 1050 patients were randomly assigned to LDG (n = 526) or ODG group (n = 524) between November 2011 and April 2015. After excluding patients who received bypass or no surgery, 1011 patients were analyzed as actual treatment group. Mean number of totally retrieved lymph nodes was similar in both groups (LDG = 46.6 vs ODG = 47.4, P = 0.451). Early morbidity rate was significantly lower after LDG (16.6%) than after ODG (24.1%; P = 0.003). Postoperative analgesics use and patients' reported pain score were significantly lower after LDG. First day of flatus was earlier after LDG (3.5 vs 3.7 d, P = 0.025) and postoperative hospital stay was shorter in LDG group (8.1 vs 9.3 d, P = 0.005). Ninety days' mortality rate was similar in both groups (LDG = 0.4% vs ODG = 0.6%, P = 0.682).

CONCLUSIONS

Laparoscopic distal gastrectomy with D2 lymphadenectomy for locally advanced gastric cancer shows benefits in terms of lower complication rate, faster recovery, and less pain compared with open surgery.

Relationship between Clavien-Dindo classification and long-term survival outcomes after curative resection for gastric cancer: A propensity score-matched analysis

BACKGROUND

The impact of postoperative complications (POCs) on the long-term survival outcomes after curative resection for gastric cancer has seldom been reported. The purpose of this study was to evaluate the relationship between the severity of POCs and long-term survival outcomes after curative resection for gastric cancer.

METHODS

The study analyzed 3091 patients who underwent curative resection for gastric cancer in a single center between June 2009 and June 2015. Patients were divided into two groups based on the occurrence or absence of postoperative complications which were recorded using the Clavien-Dindo classification. Long-term survival outcomes were compared between groups after propensity score matching (PSM).

RESULTS

A total of 3091 patients were included in the entire cohort. After PSM, no significant difference in baseline data was observed between the complications (C) group (n = 375) and no complications (NC) group (n = 375). With a median follow-up of 51 months, POCs were associated with decreased 5-year overall survival (OS) (51.7% vs. 67.5%, P < 0.001), disease-free survival (DFS) (49.9% vs. 65.6%, P < 0.001), and disease-specific survival (DSS) (53.9% vs. 68.8%, P < 0.001). Increasing Clavien-Dindo grades from II to IV was significantly associated with a corresponding decrease in OS (60, 48.3, 34%, P = 0.010), DFS (58.3, 46.3, 32.1%, P < 0.001) and DSS (62.9, 50.3, 34%, P < 0.001). Multivariate analysis confirmed POCs was an independent prognostic factor for decreased OS, DFS, and DSS (all P < 0.05).

CONCLUSIONS

POCs had a negative impact on long-term survival outcomes after curative resection for gastric cancer. The negative effects were also increased with higher Clavien-Dindo grades.

Which method is more suitable for advanced gastric cancer with enlarged lymph nodes, laparoscopic radical gastrectomy or open gastrectomy?

BACKGROUND

The oncologic outcome of laparoscopic radical gastrectomy (LG) with open radical gastrectomy (OG) for gastric cancer with preoperative enlarged lymph nodes (LNs) remains ambiguous.

METHODS

The long-term outcomes of LG (n = 855) versus OG (n = 154) in gastric adenocarcinoma patients were analyzed retrospectively. Patients were stratified according to enlarged (> 10 mm) and small (≤ 10 mm) LNs (ELN and SLN) based on the long-axis diameter of the LNs.

RESULTS

The violin plot indicates that the distribution of ELN size was similar between two groups. Survival curves demonstrated that the overall survival (OS) in LG is enhanced compared with OG (p = 0.034). A stratified analysis revealed that the OS was better in the LG group compared with the OG group for patients with ELNs (p = 0.038). In a forest map analysis, the actual 3-year OS rate for LG was significantly increased compared with OG in enlarged suprapancreatic LN (ESLNs) patients. Stratified analysis based on different diameters of ESLNs revealed that the actual 3-year OS and cancer-specific survival (CSS)rate for LG was significant increased compared to OG with a diameter from 1.0 to 1.9 cm for pII or pIII stage patients. However, the actual 3-year OS and CSS rate for LG was significantly reduced compared with OG when the size exceeded 2.5 cm.

CONCLUSIONS

For advanced gastric cancer with an ESLN diameter from 1.0 to 1.9 cm, LG could be chosen preferentially; nevertheless, LG is not safe if ESLN are > 2.5 cm.

Preoperative Therapy for Gastric Adenocarcinoma is Protective for Poor Oncologic Outcomes in Patients with Complications After Gastrectomy

BACKGROUND

Postoperative complications (POC) are associated with poor oncologic outcomes in gastric cancer. We sought to evaluate the impact of POC on survival in patients with gastric cancer treated with upfront surgery (UpSurg) versus those treated with preoperative therapy (PreT).

METHODS

We analyzed data from a prospectively maintained database of patients who had undergone resection of their gastric cancer at our institution. Patients with T1N0 or M1 lesions, recurrent disease, and mortality within 90 days were excluded. Survival was compared between patients with and without POC in the UpSurg and PreT groups. Cox regression analyses were used to examine factors associated with overall survival (OS) and disease-free survival (DFS).

RESULTS

A total of 421 patients underwent resection of gastric cancer: 30% underwent upfront surgery, and 51% had a POC. Among patients who had POCs, 71% were infectious and 53% were Clavien-Dindo grade III or IV. UpSurg patients with a POC had shorter OS (5-year, 47 vs. 85%; p < 0.001) and DFS (5-year, 46 vs. 76%; p < 0.001) than those without a POC. In contrast, there was no difference in OS (5-year, 57 vs. 63%; p = 0.77) and DFS (5-year, 52 vs. 52%; p = 0.52) between PreT patients with and without POC. Multivariable Cox regression model demonstrated that a POC in UpSurg patients had significant impact on DFS (2.6 [95% confidence interval (CI) 1.48-4.74]), whereas it did not in PreT patients (0.9 [95% CI 0.70-1.33]).

CONCLUSIONS

The use of preoperative therapy negated the impact of POCs on OS and DFS in patients undergoing resection for gastric cancer.

An Augmented Reality Endoscope System for Ureter Position Detection

Iatrogenic injury of ureter in the clinical operation may cause the serious complication and kidney damage. To avoid such a medical accident, it is necessary to provide the ureter position information to the doctor. For the detection of ureter position, an ureter position detection and display system with the augmented ris proposed to detect the ureter that is covered by human tissue. There are two key issues which should be considered in this new system. One is how to detect the covered ureter that cannot be captured by the electronic endoscope and the other is how to display the ureter position that provides stable and high-quality images. Simultaneously, any delayed processing of the system should disturb the surgery. The aided hardware detection method and target detection algorithms are proposed in this system. To mark the ureter position, a surface-lighting plastic optical fiber (POF) with the encoded light-emitting diode (LED) light is used to indicate the ureter position. The monochrome channel filtering algorithm (MCFA) is proposed to locate the ureter region more precisely. The ureter position is extracted using the proposed automatic region growing algorithm (ARGA) that utilizes the statistical information of the monochrome channel for the selection of growing seed point. In addition, according to the pulse signal of encoded light, the recognition of bright and dark frames based on the aided hardware (BDAH) is proposed to expedite the processing speed. Experimental results demonstrate that the proposed endoscope system can identify 92.04% ureter region in average.

[Endoscopic and surgical treatment of early gastric and esophageal carcinoma]

BACKGROUND

The treatment of early gastric (EGC) and esophageal carcinomas (EEC) is an interdisciplinary challenge. The risk of lymph node metastasis (LNM) is the crucial point in choosing the correct treatment option.

OBJECTIVE

This article gives an overview of the current treatment options and provides help in choosing the correct therapy.

METHOD

Current concepts and therapy algorithms are presented on the basis of a literature review and data from our own center.

RESULTS

Endoscopic submucosal dissection (ESD) is recommended for mucosal gastric cancer with good or moderate differentiation (G1,2) without macroscopic ulceration, in elevated type lesions smaller than 2 cm in size or depressed lesions smaller than 1 cm in size. In additional chromoendoscopy should be carried out. The extent of surgical resection is defined by the location of the tumor. A safety margin of at least 3 cm should be applied in distal gastric resections whereas the first line goal in gastrectomy is to achieve an R0 resection. In cN0 tumors a D1 lymphadenectomy (LA) seems to be sufficient. Minimally invasive techniques currently show promising results especially for a subtotal resection. The treatment strategy in EEC differs depending on the tumor entity. Mucosal squamous cell carcinoma with high risk factors (L1,V1) and all cN0 submucosal tumors without the detection of LNM should be referred to primary surgical resection. Early stage cN+ squamous cell carcinomas should be preoperatively treated with chemoradiotherapy. Adenocarcinoma with infiltration of the deeper submucosa (sm2,3) and high-risk sm1 tumors require surgical treatment. The standard operating procedure for EEC is an Ivor Lewis esophagectomy with 2‑field LA preferably performed as a hybrid or by a completely minimally invasive procedure. The procedure of choice in endoscopic resection of EEC is resection with the suck and cut technique.

Laparoscopic gastrectomy in obese gastric cancer patients: a comparative study with non-obese patients and evaluation of difference in laparoscopic methods

Background

Obesity is a growing epidemic around the world, and obese patients are generally regarded as high risk for surgery compared with normal weight patients. The purpose of this study was to evaluate the influence of obesity on the surgical outcomes of laparoscopic gastrectomy (LG) for gastric cancer.

Methods

We reviewed data for all patients undergoing LG for gastric cancer at our institute between October 2004 and December 2016. Patients were divided into non-obese and obese groups and the perioperative outcomes were compared. Furthermore, a subgroup analysis was conducted to evaluate which of the two commonly used methods of LG, laparoscopic-assisted gastrectomy (LAG) and totally laparoscopic gastrectomy (TLG), is more suitable for obese patients.

Results

A total of 1691 patients, 1255 non-obese and 436 obese or overweight patients, underwent LG during the study period. The mean operation time was significantly longer in the obese group than in the non-obese group (209.9 ± 29.7 vs. 227.2 ± 25.7 min, P < 0.01), and intraoperative blood loss was significantly lower in the non-obese group (113.4 ± 34.1 vs. 136.9 ± 36.7 ml, P < 0.01). Time to first flatus, time to oral intake, and postoperative hospital stay were significantly shorter in the non-obese group than in the obese group (3.3 ± 0.8 vs. 3.6 ± 0.9 days; 4.3 ± 1.0 vs. 4.6 ± 1.0 days; and 9.0 ± 2.2 vs. 9.6 ± 2.2 days, respectively; P < 0.01). 119 (9.5%) of the non-obese patients had postoperative complications as compared to 44 (10.1%) of the obese patients (P = 0.71). In the subgroup analysis of all patients, TLG showed improved results for early surgical outcomes compared to LAG, mainly due to its advantages in obese patients.

Conclusions

Obesity is associated with long operation time, increased blood loss, and slow recovery after laparoscopic gastric resection but does not affect intraoperative security or effectiveness. TLG may have less negative results in obese patients than LAG due to a variety of reasons. Our analysis shows that TLG is more advantageous, with regard to early surgical outcomes, for obese patients.

Minimally invasive surgery for gastric cancer in UK: current status and future perspectives

The aim of this study is to review the literature and report the various minimally invasive methods used to treat gastric cancer in the UK and compare it with worldwide practice. Published randomised studies, non-randomised studies and case series reporting the use of minimal invasive approach to treat gastric cancer were retrieved from the search of standard medical electronic databases and their outcomes were highlighted suggesting their effectiveness. Several randomised, controlled trials and meta-analyses have proven the clinical and oncological safety of the laparoscopic gastrectomy for gastric cancer. Similarly, robot-assisted gastrectomy, EMR (endoscopic mucosal resection) and ESD (endoscopic sub-mucosal dissection) have also been proven feasible and safe to treat gastric cancer of various stages in prospective and retrospective comparative studies. However, UK based studies on minimally invasive surgery to treat gastric cancer is scarce and the paucity of trials led to uncertain outcomes. Laparoscopic gastrectomy, robot-assisted gastrectomy, EMR and ESD are feasible procedures in terms of clinical and oncological safety but mainly being practiced in Asian countries with high prevalence of stomach cancer. The UK based practice is still small and limited but the introduction of MIGOCS and STOMACH trial might help to widen the application of this technique.

Do preoperative enlarged lymph nodes affect the oncologic outcome of laparoscopic radical gastrectomy for gastric cancer?

BACKGROUND

To investigate the long-term outcome of laparoscopic radical gastrectomy (LAG) for gastric cancer (GC) with preoperative enlarged lymph nodes (LNs).

MATERIALS AND METHODS

We retrospectively collected data on 855 patients who underwent LAG for GC. The patients were divided into large (>10 mm) and small (≤10 mm) LN groups (LG and SG) based on the preoperative size of the LNs. The outcomes were compared using a 1:1 propensity score-matching method. The enlarged LNs were divided into five areas according to their location.

RESULTS

Before matching, the LG was associated with more retrieved LNs than the SG, whereas after matching, the numbers of LNs retrieved were similar. These numbers remained similar as the number of areas with enlarged LNs increased. Before matching, patients in the LG demonstrated a significantly lower 3-year overall survival rate than those in the SG (p < 0.001). Additionally, in the LG, 3-year overall survival rates were similar among patients with different total numbers of areas with enlarged LNs. After matching, the 3-year overall survival rate of the LG was close to that of the SG (81.1% vs. 72.4%, p = 0.066). A stratified analysis according to the only independent prognostic factor (pTNM stage) demonstrated that the 3-year overall survival rates at each stage were similar between the LG and SG.

CONCLUSIONS

LAG has similar oncologic outcomes for GC with or without preoperative enlarged LNs in the same tumor stage. Furthermore, the total number of areas with enlarged LNs has no impact on the long-term outcome.

Comparison Between Billroth-II with Braun and Roux-en-Y Reconstruction After Laparoscopic Distal Gastrectomy

PURPOSE

This study aims to compare the effectiveness of Billroth-II with Braun and Roux-en-Y reconstruction after laparoscopic distal gastrectomy.

METHODS

From April 2010 to August 2012, 66 patients underwent laparoscopic distal gastrectomy (Billroth-II with Braun reconstruction, 26; Roux-en-Y, 40). The patients' data were collected prospectively and reviewed retrospectively.

RESULTS

The mean operation and reconstruction times were statistically shorter for Billroth-II with Braun reconstruction than Roux-en-Y (198.1 ± 33.0 vs. 242.3 ± 58.1 min, p = 0.001). One case of postoperative stricture was observed in each group. One case each of intra-abdominal abscess and delayed gastric emptying occurred in the Billroth-II with Braun group. At 1 year postoperatively, gastric residue and reflux esophagitis were not significantly different between the groups. Gastritis and bile reflux were more frequently observed in the Billroth-II with Braun group (p = 0.004 and p < 0.001, respectively). At 2 years postoperatively, gastric residue was not significantly different, but gastritis, bile reflux, and esophagitis were more frequent in the Billroth-II with Braun group (p = 0.029, p < 0.001, and p = 0.036, respectively).

CONCLUSION

The postoperative effectiveness of Roux-en-Y reconstruction may be superior to Billroth-II with Braun reconstruction after laparoscopic distal gastrectomy.

Single incision gastrectomy for gastric cancer

Based on rapid development of laparoscopic techniques and instruments, single-incision laparoscopic surgery (SILS) is expected to be the next step of "more" minimally invasive surgery. A few institutions gradually started to report their experience of single incision gastrectomy (SIG) for gastric cancer, but it is still difficult to accept that SIG can be performed as a popular procedure because of its technical difficulty. For wide adoption of SIG, the simplicity, safety and reproducibility of not only lymph node dissection but also reconstruction should be evaluated compared to a conventional procedure. With a thorough understanding of unique characteristics of SILS, single incision distal gastrectomy (SIDG) for early gastric cancer performed by laparoscopic surgeons with advanced technique is expected to have promising potential about excellent cosmesis, comparable morbidity and mortality in carefully selected patients. For appropriate adoption and steady progress of this state-of-the art surgery, scientific evaluation with healthy critics is necessary with new generation of SILS instrument platform.

Recent developments and innovations in gastric cancer

Gastric cancer has an important place in the worldwide incidence of cancer and cancer-related deaths. It can metastasize to the lymph nodes in the early stages, and lymph node metastasis is an important prognostic factor. Surgery is a very important part of gastric cancer treatment. A D2 lymphadenectomy is the standard surgical treatment for cT1N+ and T2-T4 cancers, which are potentially curable. Recently, the TNM classification system was reorganized, and the margins for gastrectomy and lymphadenectomy were revised. Endoscopic, laparoscopic and robotic treatments of gastric cancer have progressed rapidly with development of surgical instruments and techniques, especially in Eastern countries. Different endoscopic resection techniques have been identified, and these can be divided into two main categories: endoscopic mucosal resection and endoscopic submucosal dissection. Minimally invasive surgery has been reported to be safe and effective for early gastric cancer, and it can be successfully applied to advanced gastric cancer with increasing experience. Cytoreductive surgery and hyperthermıc intraperıtoneal chemotherapy were developed as a combined treatment modality from the results of experimental and clinical studies. Also, hyperthermia increases the antitumor activity and penetration of chemotherapeutics. Trastuzumab which is a monoclonal antibody interacts with human epidermal growth factor (HER) 2 and is related to gastric carcinoma. The anti-tumor mechanism of trastuzumab is not clearly known, but mechanisms such as interruption of the HER2-mediated cell signaling pathways and cell cycle progression have been reported previously. H. pylori is involved in 90% of all gastric malignancies and Japanese guidelines strongly recommend that all H. pylori infections should be eradicated regardless of the associated disease. In this review, we present innovations discussed in recent studies.

Interaction of Postoperative Morbidity and Receipt of Adjuvant Therapy on Long-Term Survival After Resection for Gastric Adenocarcinoma: Results From the U.S. Gastric Cancer Collaborative

BACKGROUND

Postoperative complications (POCs) can negatively impact survival after oncologic resection. POCs may also decrease the rate of adjuvant therapy completion. We evaluated the impact of complications on gastric cancer survival and analyzed the combined effect of complications and adjuvant therapy on survival.

METHODS

We analyzed 824 patients from 7 institutions of the U.S. Gastric Cancer Collaborative who underwent curative resection for gastric adenocarcinoma between 2000 and 2012. POC were graded using the modified Clavien-Dindo system. Survival probabilities were estimated using the method of Kaplan and Meier and analyzed using multivariate Cox regression.

RESULTS

Median follow-up was 35 months. The overall complication rate was 41 %. The 5-year overall survival (OS) and recurrence-free survival (RFS) of patients who experienced complications were 27 and 23 %, respectively, compared with 43 and 40 % in patients who did not have complications (p < 0.0001 for OS and RFS). On multivariate analysis, POC remained an independent predictor for decreased OS and RFS (HR 1.3, 95 % CI 1.1-1.6, p = 0.03 for OS; HR 1.3, 95 % CI 1.01-1.6, p = 0.03 for RFS). Patients who experienced POC were less likely to receive adjuvant therapy (OR 0.5, 95 % CI 0.3-0.7, p < 0.001). The interaction of complications and failure to receive adjuvant therapy significantly increased the hazard of death compared with patients who had neither complications nor adjuvant therapy (HR 2.3, 95 % CI 1.6-3.2, p < 0.001).

CONCLUSIONS

Postoperative complications adversely affect long-term outcomes after gastrectomy for gastric cancer. Not receiving adjuvant therapy in the face of POC portends an especially poor prognosis following gastrectomy for gastric cancer.

Laparoscopic surgery: A qualified systematic review

AIM: To review current applications of the laparoscopic surgery while highlighting the standard procedures across different fields.

METHODS: A comprehensive search was undertaken using the PubMed Advanced Search Builder. A total of 321 articles were found in this search. The following criteria had to be met for the publication to be selected: Review article, randomized controlled trials, or meta-analyses discussing the subject of laparoscopic surgery. In addition, publications were hand-searched in the Cochrane database and the high-impact journals. A total of 82 of the findings were included according to matching the inclusion criteria. Overall, 403 full-text articles were reviewed. Of these, 218 were excluded due to not matching the inclusion criteria.

RESULTS: A total of 185 relevant articles were identified matching the search criteria for an overview of the current literature on the laparoscopic surgery. Articles covered the period from the first laparoscopic application through its tremendous advancement over the last several years. Overall, the biggest advantage of the procedure has been minimizing trauma to the abdominal wall compared with open surgery. In the case of cholecystectomy, fundoplication, and adrenalectomy, the procedure has become the gold standard without being proven as a superior technique over the open surgery in randomized controlled trials. Faster recovery, reduced hospital stay, and a quicker return to normal activities are the most evident advantages of the laparoscopic surgery. Positive outcomes, efficiency, a lower rate of wound infections, and reduction in the perioperative morbidity of minimally invasive procedures have been shown in most indications.

CONCLUSION: Improvements in surgical training and developments in instruments, imaging, and surgical techniques have greatly increased safety and feasibility of the laparoscopic surgical procedures.

Current status of randomized controlled trials for laparoscopic gastric surgery for gastric cancer in China

China alone accounts for nearly 42% of all new gastric cancer cases worldwide, and gastric cancer is the third leading cause of cancer deaths in China nowadays. Without mass screening programs, unfortunately over 80% of all Chinese patients have been diagnosed as advanced diseases. As in other Asian countries, especially Japan and Korea, laparoscopic gastrectomy for the treatment of gastric cancer has gained increasingly popularity in China during the past decade. Whether laparoscopic surgery can be safely and effectively performed in the treatment of gastric cancer remains controversial, particularly with regard to curative intent in advanced diseases. Given the high incidence of these cancers, and their advanced stage at diagnosis, China has a significant interest in determining the safety and effectiveness of laparoscopic gastrectomy. A well-designed randomized controlled trial (RCT) is considered the only feasible way to provide conclusive evidence. To date, China has not played a significant role in terms of conducting RCT concerning laparoscopic surgery for gastric cancer. However, an effort has been made by the Chinese researchers, with the great help from our colleagues in neighboring countries such as Korea and Japan, through the establishment of the Chinese Laparoscopic Gastrointestinal Surgery Study Group. In this review, we present the current status of RCT for laparoscopic gastric surgery for gastric cancer in China, including published and ongoing registered RCT.

Unaided Stapling Technique for Pure Single-Incision Distal Gastrectomy in Early Gastric Cancer: Unaided Delta-Shaped Anastomosis and Uncut Roux-en-Y Anastomosis

Purpose

Intracorporeal anastomosis is the most difficult procedure during pure single-incision distal gastrectomy (SIDG) that affects its generalization. We introduced unaided delta-shaped anastomosis (uDelta), a novel anastomosis technique, for gastroduodenostomy after pure SIDG, and compared the results with those of previously reported Roux-en-Y anastomosis (RY).

Materials and Methods

Between March 2014 and March 2015, SIDG with D1+ lymph node dissection was performed for early gastric cancer through a 2.5-cm transumbilical incision without any additional port. uDelta was performed by the operator alone, without any intracorporeal assistance.

Results

uDelta was performed on 11 patents, and uncut RY was performed on 5-patients without open or multiport conversion. R0 resection was performed in all cases. No significant differences were observed in mean age and body mass index between patients who underwent uDelta or RY. Mean operation times were 214.5±36.2 minutes for uDelta and 240.8±65.9 minutes for RY, which was not significantly different. Reconstruction time for uDelta was shorter than that for RY, with marginal statistical significance (26.1±8.3 minutes vs. 38.0±9.1 minutes, P=0.05). There were no intraoperative transfusions, 30-day mortality, or anastomosis-related complications in either group. Average length of hospital stay was 8.2±1.9 days in the uDelta group and 7.2±0.8 days in the RY group (P=0.320).

Conclusions

After carefully considering indications, uDelta can be a feasible and can be a reproducible reconstruction method after SIDG in early gastric cancer.

Surgical techniques, open versus minimally invasive gastrectomy after chemotherapy (STOMACH trial): study protocol for a randomized controlled trial

Background

Laparoscopic surgery has been shown to provide important advantages in comparison with open procedures in the treatment of several malignant diseases, such as less perioperative blood loss and faster patient recovery. It also maintains similar results with regard to tumor resection margins and oncological long-term survival. In gastric cancer the role of laparoscopic surgery remains unclear.

Current recommended treatment for gastric cancer consists of radical resection of the stomach, with a free margin of 5 to 6 cm from the tumor, combined with a lymphadenectomy. The extent of the lymphadenectomy is considered a marker for radicality of surgery and quality of care. Therefore, it is imperative that a novel surgical technique, such as minimally invasive total gastrectomy, should be non-inferior with regard to radicality of surgery and lymph node yield.

Methods/Design

The Surgical Techniques, Open versus Minimally invasive gastrectomy After CHemotherapy (STOMACH) study is a randomized, clinical multicenter trial. All adult patients with primary carcinoma of the stomach, in which the tumor is considered surgically resectable (T1-3, N0-1, M0) after neo-adjuvant chemotherapy, are eligible for inclusion and randomization. The primary endpoint is quality of oncological resection, measured by radicality of surgery and number of retrieved lymph nodes. The pathologist is blinded towards patient allocation. Secondary outcomes include patient-reported outcomes measures (PROMs) regarding quality of life, postoperative complications and cost-effectiveness. Based on a non-inferiority model for lymph node yield, with an average lymph node yield of 20, a non-inferiority margin of −4 and a 90% power to detect non-inferiority, a total of 168 patients are to be included.

Discussion

The STOMACH trial is a prospective, multicenter, parallel randomized study to define the optimal surgical strategy in patients with proximal or central gastric cancer after neo-adjuvant therapy: the conventional ‘open’ approach or minimally invasive total gastrectomy.

Trial registration

This trial was registered on 28 April 2014 at Clinicaltrials.gov with the identifier NCT02130726.

Minimally invasive surgery for gastric cancer treatment: current status and future perspectives

Minimally invasive surgery, which has been extensively used to treat gastric adenocarcinoma, is now regarded as one of the standard treatments for early gastric cancer, and its suitability for advanced gastric cancer is being investigated. The use of cutting-edge techniques for minimally invasive surgery enables surgeons to deliver various treatment options to minimize a patient's distress and to maintain oncologic safety. Ongoing multicenter prospective studies aim to validate the efficacy of these surgical techniques and to expand the indications of minimally invasive surgery for the treatment of gastric cancer. In this review, we summarize the current status and issues regarding minimally invasive surgery for the treatment of gastric cancer.