Clinical Efficacy of Laparoscopic Sentinel Node Navigation Surgery for Stomach Preservation in Patients With Early Gastric Cancer: 5-year Results of the SENORITA Trial.

OBJECTIVE: This study aimed to compare laparoscopic standard gastrectomy (LSG) and laparoscopic sentinel node navigation surgery (LSNNS) for EGC in terms of 5-year long-term oncologic outcomes. SUMMARY BACKGROUND DATA: The oncological safety of LSNNS for early gastric cancer (EGC) has not been confirmed. Three-year disease-free survival (DFS), which is the primary endpoint of the phase III multicenter randomized controlled clinical trial (SEntinel Node ORIented Tailored Approach [SENORITA] trial), did not show the non-inferiority of LSNNS relative to LSG. METHODS: The SENORITA trial, a multicenter randomized clinical trial, was designed to show that LSNNS is non-inferior to LSG in terms of 3-year DFS. In the present study, we collected 5-year follow-up data from 527 patients recruited in the SENORITA trial as the full analysis set (FAS). Disease-free survival (DFS), overall survival (OS), disease-specific survival (DSS), and recurrence patterns were evaluated using the FAS of both LSG (n=269) and LSNNS (n=258). RESULTS: The 5-year DFS was not significantly different between the LSG and LSNNS groups (P=0.0561). During the 5-year follow-up, gastric cancer-related events, such as metachronous cancer, were more frequent in the LSNNS group than in the LSG group. However, ten recurrent cancers in the remnant stomach of both groups were curatively resected by additional gastrectomy and one by additional endoscopic resection. Two of the 198 patients who underwent local resection for stomach preservation based on the LSNNS results developed distant metastasis. However, there was no statistically significant difference in the 5-year OS and DSS (P=0.7403 and P=0.9586, respectively) between the two groups. CONCLUSION: The 5-year DFS, DSS and OS did not differ significantly between the two groups. Considering the benefits of LSNNS on postoperative quality of life, LSNNS could be recommended as an alternative treatment option for EGC.

Feasibility of intraoperative pathologic examination for sentinel lymph nodes during sentinel node navigation surgery in early gastric cancer: results of pathologic protocol for SENORITA trial.

BACKGROUND: During sentinel node navigation surgery in patients with gastric cancer, intraoperative pathologic examination of sentinel nodes is crucial in determining the extent of surgery. In this study, we evaluated the feasibility and accuracy of intraoperative pathologic protocols using data from a prospective, multicenter, randomized trial. METHODS: A retrospective analysis was conducted using data from the SEntinel Node ORIented Tailored Approach trials from 2013 to 2016. All sentinel lymph nodes were evaluated during surgery with hematoxylin-eosin (HE) staining using a representative section at the largest plane for lymph nodes. For permanent histologic evaluation, sentinel basin nodes were stained with HE and cytokeratin immunohistochemistry in formalin-fixed, paraffin-embedded (FFPE) sections and examined with HE for three deeper-step sections at 200-µm intervals. The failure rate of identification by frozen section and the metastasis rate in non-sentinel basins were investigated. RESULTS: Of the 237 patients who underwent sentinel node basin dissection, 30 had lymph node metastases on permanent pathology. Thirteen patients had macrometastasis confirmed in frozen sections as well as FFPE sections (failure rate: 0%). Patients with negative sentinel nodes in frozen sections but micrometastasis in FFPE sections had no lymph node recurrence during the follow-up period (0%, 0/6). However, in cases with tumor-positive nodes in frozen sections, metastases in non-sentinel basins were detected in the paraffin blocks (8.3%, 2/24). CONCLUSIONS: The single-section HE staining method is sufficient for detecting macrometastasis via intraoperative pathological examination. If a negative frozen-section result is confirmed, sentinel basin dissection can be performed safely. Otherwise, standard surgery is required.

Stomach tissue classification using autofluorescence spectroscopy and machine learning.

BACKGROUND AND OBJECTIVES: Determination of stomach tumor location and invasion depth requires delineation of gastric histological structure, which has hitherto been widely accomplished by histochemical staining. In recent years, alternative histochemical evaluation methods have been pursued to accelerate intraoperative diagnosis, often by bypassing the time-consuming step of dyeing. Owing to strong endogenous signals from coenzymes, metabolites, and proteins, autofluorescence spectroscopy is a favorable candidate technique to achieve this aim. MATERIALS AND METHODS: We investigated stomach tissue slices and block specimens using a fast fluorescence imaging scanner. To obtain histological information from broad and structureless fluorescence spectra, we analyzed tens of thousands of spectra with multiple machine-learning algorithms and built a tissue classification model trained with dissected gastric tissues. RESULTS: A machine-learning-based spectro-histological model was built based on the autofluorescence spectra measured from stomach tissue samples with delineated and validated histological structures. The scores from a principal components analysis were employed as input features, and prediction accuracy was confirmed to be 92.0%, 90.1%, and 91.4% for mucosa, submucosa, and muscularis propria, respectively. We investigated the tissue samples in both sliced and block forms using a fast fluorescence imaging scanner. CONCLUSION: We successfully demonstrated differentiation of multiple tissue layers of well-defined specimens with the guidance of a histologist. Our spectro-histology classification model is applicable to histological prediction for both tissue blocks and slices, even though only sliced samples were trained.

Gastric cancer surgery in South Korea: Past, present, and future.

Gastric cancer remains a significant global health concern and its surgical management approaches have undergone significant changes in South Korea and worldwide. Subtotal or total gastrectomy with D2 lymph node dissection is well established as a standard surgical procedure for gastric cancer. With the active implementation of cancer screening in South Korea, the proportion of early gastric cancer cases has significantly increased over the past few decades, leading to a steady increase in the survival rate among patients. Furthermore, recent advances in surgical instruments and techniques have made minimally invasive surgery increasingly prevalent, not only for early but also for advanced gastric cancer. We aim to provide a comprehensive overview of the evolution and current status of gastric cancer surgery in South Korea.

Ergonomic effects of medical augmented reality glasses in video-assisted surgery.

BACKGROUND: The aim of this study was to objectively compare medical augmented reality glasses (ARG) and conventional monitors in video-assisted surgery and to systematically analyze its ergonomic benefits. METHODS: Three surgeons (thoracic, laparoscopic, and thyroid surgeons) participated in the study. Six thoracoscopic metastasectomies, six subtotal laparoscopic gastrectomies, and six thyroidectomies were performed with and without ARG. The subjective experience was evaluated using a questionnaire-based NASA-Task Load Index (NASA-TLX). Postures during surgeries were recorded. The risk of musculoskeletal disorders associated with video-assisted surgery was assessed using rapid entire body assessment (REBA). Surface electromyography (EMG) was recorded. Muscle fatigue was objectively measured. RESULTS: NASA-TLX scores of three surgeons were lower when ARG was used compared to those with conventional monitor (66.4 versus 82.7). Less workload during surgery was reported with ARG. The laparoscopic surgeon exhibited a substantial decrease in mental and physical demand [- 21.1 and 12.5%)] and the thyroid surgeon did (- 40.0 and - 66.7%).Total REBA scores decreased with ARG (8 to 3.6). The risk of musculoskeletal disorders was improved in regions of the neck and shoulders. Root mean square (RMS) of the EMG signal decreased from 0.347 ± 0.150 to 0.286 ± 0.130 (p = 0.010) with usage of ARG; a decrease was observed in all surgeons. The greatest RMS decrease was observed in trapezius and sternocleidomastoid muscles. The decrease in brachioradialis muscle was small. CONCLUSION: ARG assisted with correction of bad posture in surgeons during video-assisted surgery and reduced muscular fatigue of the upper body. This study highlights the superior ergonomic efficiency of ARG in video-assisted surgery.

Efficacy of endoscopic management for anastomotic leakage after gastrectomy in patients with gastric cancer.

BACKGROUND: Anastomotic leakage (AL) after gastrectomy in gastric cancer patients is associated with high mortality rates. Various endoscopic procedures are available to manage this postoperative complication. The aim of study was to evaluate the outcome of two endoscopic modalities, clippings and stents, for the treatment of AL. PATIENTS AND METHODS: There were 4916 gastric cancer patients who underwent gastrectomy between December 2007 and January 2016 at the National Cancer Center, Korea. A total of 115 patients (2.3%) developed AL. Of these, 85 patients (1.7%) received endoscopic therapy for AL and were included in this retrospective study. The endpoints were the complete leakage closure rates and risk factors associated with failure of endoscopic therapy. RESULTS: Of the 85 patients, 62 received endoscopic clippings (with or without detachable snares), and 23 received a stent insertion. Overall, the complete leakage closure rate was 80%, and no significant difference was found between the clipping and stent groups (79.0% vs. 82.6%, respectively; P = 0.89). The complete leakage closure rate was significantly lower in the duodenal and jejunal stump sites (60%) than esophageal sites (86.1%) and gastric sites (94.1%; P = 0.026). The multivariate analysis showed that stump leakage sites (adjusted odds ratio [aOR], 4.51; P = 0.031) and the presence of intra-abdominal abscess (aOR, 4.92; P = -0.025) were associated with unsuccessful leakage closures. CONCLUSIONS: Endoscopic therapy using clippings or stents is an effective method for the postoperative management of AL in gastric cancer patients. This therapy can be considered a primary treatment option due to its demonstrated efficacy, safety, and minimally invasive nature.

Effectiveness of Intraoperative Endoscopy for Localization of Early Gastric Cancer during Laparoscopic Distal Gastrectomy.

INTRODUCTION: Intraoperative localization of tumors has been considered crucial in determining adequate resection margins during laparoscopic gastrectomy for early gastric cancer (EGC). This study has evaluated the effectiveness of intraoperative endoscopy for localization of EGC during the totally laparoscopic distal gastrectomy. METHODS: Patients with EGC who received totally laparoscopic distal gastrectomy from January 2018 to March 2020 were included in this study. Except the tumors located in the antrum, the patients were categorized into two groups: no localization procedure (n = 144) and intraoperative endoscopy (n = 65). To evaluate the effectiveness of the localization procedure, proximal resection margin (PRM) involvement by the tumor and approximation of optimal PRM were compared, including their postoperative outcomes. RESULTS: There were 3 patients (2.1%) with tumor involvement of the PRM at the initial gastric resection in the no localization group. Distance from the tumor to the PRM was determined to be not significantly different between the no localization group and intraoperative endoscopy group. The PRM distribution pattern and reconstruction method were also not significantly different between the two groups. DISCUSSION/CONCLUSION: Intraoperative endoscopy for localization of EGC is an effective method to avoid tumor involvement at the resection margin during the laparoscopic gastrectomy with intracorporeal gastric resection and reconstruction.

Risks and benefits of additional surgery for early gastric cancer in the upper third of the stomach meeting non-curative resection criteria after endoscopic submucosal dissection.

BACKGROUND: Additional surgery is recommended after non-curative endoscopic submucosal dissection for early gastric cancer. However, it is not easy to recommend for tumors located in the upper third of the stomach, because it would be a total or proximal gastrectomy. This study aimed to evaluate the actual risks and benefits of additional gastrectomy for upper third tumors. METHODS: We reviewed the clinicopathological data of patients who underwent total or proximal gastrectomy for early gastric cancer in the upper third of the stomach between March 2002 and January 2021. The incidence of lymph node metastasis and postoperative complications were calculated, and risk factors for lymph node metastasis were identified using logistic regression analysis. Survival rates were analyzed using the Kaplan-Meier method and log-rank test. RESULTS: A total of 523 patients underwent total or proximal gastrectomy for early gastric cancer; 379 of them had tumors meeting the non-curative resection criteria for endoscopic submucosal dissection. The overall lymph node metastasis rate was 9.5%, and lymphovascular invasion was the only significant risk factor for lymph node metastasis (p < 0.001). The most common sites of lymph node metastasis were stations 1, 3, and 7, with their rates being 3.2%, 3.7%, and 3.2%, respectively. Overall and severe (Clavien-Dindo grade III or higher) postoperative complication rates were 21.1% and 14.0%, respectively, while postoperative mortality was 0.5% (2/379). The 5-year overall survival rates for patients with and without lymph node metastasis were 96.1% and 81.1%, respectively (p = 0.076). CONCLUSIONS: Before planning an additional gastrectomy after non-curative endoscopic resection for the upper third tumor, we should consider both the benefit of the 9.5% curability for lymph node metastasis and the risks of the 21% postoperative complications and 0.5% mortality.

Is Splenic Hilar Lymph Node Dissection Without Splenectomy Essential for Proximal Advanced Gastric Cancer?

BACKGROUND: The standard surgery for proximal advanced gastric cancer (PAGC) is total gastrectomy with D2 lymph node dissection (LND). Although prophylactic splenectomy for splenic hilar LND (No. 10) is not recommended due to any survival advantage, prophylactic LND (No. 10) without splenectomy remains controversial. Thus, we aimed to evaluate whether No. 10 LND is essential for patients' survival benefit in PAGC. METHODS: We conducted a retrospective study of 1038 patients with PAGC who underwent total gastrectomy without splenectomy. After adjusting for confounders and propensity score matching (PSM), patients were grouped into Group 1 (D2 LND without splenic hilar LN; n = 288) or Group 2 (D2 LND with splenic hilar LN; n = 288). Variables between the two groups (5-year overall survival [OS] and disease-free survival [DFS]) were compared, as well as in patients with tumors located in the greater curvature and those with Borrmann type IV disease. RESULTS: The 5-year OS and DFS rates after PSM were not significantly different between Groups 1 and 2 (57.3% vs. 62.1%, p = 0.300; 52.8% vs. 59.7%, p = 0.100, respectively). Furthermore, the 5-year OS and DFS rates in patients with greater curvature involvement (54.4% vs. 61.9%, p = 0.500; 50.0% vs. 57.6%, p = 0.400, respectively) and Borrmann type IV disease (23.8% vs. 38.6%, p = 0.400; 16.7% vs. 33.9%, p = 0.200, respectively) after PSM were also not significantly different between the two groups. CONCLUSIONS: Prophylactic splenic hilar LND without splenectomy does not improve long-term survival in PAGC. Therefore, this procedure might not be essential for patients with PAGC as well greater curvature involvement and Borrmann type IV disease.

A comparative study of the short-term operative outcome between intracorporeal and extracorporeal anastomoses during laparoscopic total gastrectomy.

BACKGROUND: Several studies have reported that intracorporeal anastomosis reduces the requirement for the additional incision for anastomosis, resulting in early recovery compared to extracorporeal anastomosis during laparoscopic distal gastrectomy. However, few studies have investigated postoperative outcome after laparoscopic total gastrectomy (LTG). We compared short-term postoperative outcomes between totally laparoscopic total gastrectomy (TLTG) with intracorporeal anastomosis and conventional laparoscopy-assisted total gastrectomy (LATG) with extracorporeal anastomosis for gastric cancer. METHODS: This retrospective case-control study included 202 patients who underwent LTG from January 2012 to June 2019. LATG was performed in the period before July 2015; TLTG was performed in the period after July 2015. Postoperative short-term outcomes and white blood cell (WBC) count, and C-reactive protein (CRP) levels at 1, 3, and 5 days postoperatively were compared between the groups. RESULTS: One hundred ten patients underwent LATG; 92 underwent TLTG. The pathologic stage was significantly higher in the TLTG group (p = 0.010). Intraoperative estimated blood loss was significantly lower in the TLTG group than in the LATG group (median [range]: 100 [50-150] mL versus [vs.] 50 [30-100], p < 0.001). Postoperative hospital stay duration was significantly longer in the TLTG group than in the LATG group (median [range]: 7 [7-9] days vs. 8 [7-11], p < 0.001). WBC count (6.3 109/L ± 1.9 vs. 8.2 ± 2.5, p = 0.004) and CRP levels (8.3 mg/L ± 6.1 vs. 13.3 ± 9.4, p < 0.001) were lower in the LATG group than in the TLTG group. The overall complication rate was higher in the TLTG group than in the LATG group (16.3% vs. 32.6%, p = 0.007). A higher American Society of Anesthesiologist score was the only significant risk factor for postoperative complications. CONCLUSION: Both procedures are feasible, although TLTG has more risk for postoperative complications than LATG. TLTG should be improved to reduce postoperative complications and provide better postoperative outcomes.

Dual modal spectroscopic tissue scanner for colorectal cancer diagnosis.

BACKGROUND: Margin status is an important prognostic factor for treating colorectal cancer. This study aimed to investigate the usefulness of a multimodal spectroscopic tissue scanner for real-time cancer diagnosis without tissue staining. PATIENTS AND METHODS: Diffuse reflectance spectra (DRS) and fluorescence spectra (FS) of < 1-mm-sized paired cancer and normal mucosa tissue were acquired using custom-built spectroscopic tissue scanners. For FS, we analyzed wavelengths and intensities at peaks and highest intensities near (± 1.25 nm) the known fluorescence spectral peaks of collagen (380 nm), reduced nicotinamide adenine dinucleotide (NADH, 460 nm), and flavin adenine dinucleotide (FAD, 550 nm). For DRS, we performed a similar analysis near the peaks of strong absorbers, oxyhemoglobin (oxyHb; 414 nm, 540 nm, and 576 nm) and deoxyhemoglobin (deoxyHb; 432 nm and 556 nm). Logistic regression analysis for these parameters was performed in the testing set. RESULTS: We acquired 17,735 spectra of cancer tissues and 9438 of normal tissues from 30 patients. Intensity peaks of representative normal spectra for FS and DRS were higher than those of representative cancer spectra. Logistic regression analysis showed wavelength and intensity at peaks, and the intensities of the peak wavelength of NADH, FAD, deoxyHb, and oxyHb had significant coefficients. The area under the receiver operating characteristic curve was 0.927. The scanner had 100%, 64.3%, and 85.3% sensitivity, specificity, and accuracy, respectively. CONCLUSIONS: The spectroscopic tissue scanner has high sensitivity and accuracy and provides real-time intraoperative resection margin assessments and should be further investigated as an alternative to frozen section.

Recent updates and current issues of sentinel node navigation surgery for early gastric cancer.

With the increase in the incidence of early gastric cancer (EGC), several endoscopic and laparoscopic approaches, such as endoscopic submucosal dissection and function-preserving gastrectomy, have been accepted as standard treatments. Sentinel node navigation surgery (SNNS) is an ideal surgical option for preservation of most parts of the stomach and consequent maintenance of normal gastric function to improve quality of life in patients with EGC. Although many previous studies and clinical trials have demonstrated the safety and feasibility of the sentinel node concept in gastric cancer, the clinical application of SNNS is debatable. Several issues regarding technical standardization and oncological safety need to be resolved. Recently several studies to resolve these problems are being actively performed, and SNNS might be an important surgical option in the treatment of gastric cancer in the future.

Factors associated with metastasis in superior mesenteric vein lymph node in subtotal gastrectomy for gastric cancer: Retrospective case control study.

OBJECTIVE: The revised Japanese treatment guideline for gastric cancer recommends dissection of the superior mesenteric vein lymph node (No. 14v LN) if there is metastasis in infrapyloric lymph node (No. 6 LN). However, it is still controversial whether LN dissection is necessary. The aim of this study was to investigate the factors associated with metastasis in No. 14v LN. METHODS: Patients who underwent D2 lymphadenectomy between 2003 and 2010 were included. We excluded patients who underwent total gastrectomy, had multiple lesions, or had missing data about the status of metastasis in the LNs that were included in D2 lymphadenectomy. Clinicopathologic characteristics and the metastasis in regional LNs were compared between patients with No. 14v LN metastasis (14v+) and those without (14v-). RESULTS: Five hundred sixty patients were included in this study. Univariate analysis showed that old age, larger tumor size, tumor location, differentiation, lymphatic invasion, venous invasion, perineural invasion, T classification, and N classification were related to metastasis in No. 14v LN. Multivariate analysis showed differentiation (P=0.027) and N classification (P<0.001) were independent related factors. Metastasis in infrapyloric lymph node (No. 6 LN) and proxiaml splenic lymph node (No. 11p LN) was independently associated with metastasis in No. 14v LN. CONCLUSIONS: Differentiation and N classification were independent factors associated with No. 14v LN metastasis, and No. 6 and No. 11p LN metastasis were independent risk factors for No. 14v LN metastasis.

The optimal extent of lymph node dissection in gastroesophageal junctional cancer: retrospective case control study.

BACKGROUND: Recently, the incidence of gastroesophageal junction (GEJ) cancer has been increasing in Eastern countries. Mediastinal lymph node (MLN) metastasis rates among patients with GEJ cancer are reported to be 5-25%. However, survival benefits associated with MLN dissection in GEJ cancer has been a controversial issue, especially in Eastern countries, due to its rarity and potential morbidity. METHODS: We retrospectively reviewed 290 patients who underwent surgery for GEJ cancer at the National Cancer Center in Korea from June 2001 to December 2015. Clinicopathologic characteristics and surgical outcomes were compared between patients without MLN dissection (Group A) and patients with MLN dissection (Group B). Prognostic factors associated with the survival rate were identified in a multivariate analysis. RESULTS: Twenty-nine (10%) patients underwent MLN dissection (Group B). Three of 29 patients (10.3%) showed a metastatic MLN in Group B. For abdominal LNs, the 5-year disease-free survival rate was 79.5% in Group A and 33.9% in Group B (P < 0.001). The multivariate analysis revealed that abdominal LN dissection, pT category, and pN category were statistically significant prognostic factors. LNs were the most common site for recurrence in both groups. CONCLUSION: Abdominal LN dissection and pathologic stage are the important prognostic factors for type II and III GEJ cancer rather than mediastinal lymph node dissection.

Effect of gastrectomy on blood pressure in early gastric cancer survivors with hypertension.

PURPOSE: We investigated the effect of gastrectomy on blood pressure (BP) in early gastric cancer survivors with hypertension and whether well-controlled BP was due solely to surgery-induced weight loss. METHODS: The study enrolled 66 early gastric cancer patients with hypertension, undergoing endoscopic submucosal dissection (ESD), or gastrectomy. Blood analyses, 24-h ambulatory BP monitoring, brachial ankle pulse wave velocity (baPWV), and echocardiography were measured prior to, 3 months after, and 1 year after ESD or gastrectomy. The primary endpoint was remission of hypertension at 1 year. RESULTS: The remission rate of hypertension was significantly higher in the gastrectomy group than in the ESD group (p = 0.006). Those with remission of hypertension had a significant weight loss (p < 0.001), decrease in body mass index (p < 0.001), 24-h total systolic BP (p = 0.047), baPWV (p = 0.042), triglycerides (p = 0.049) and apolipoprotein B/apolipoprotein A1 (p = 0.004), and an increase in high-density lipoprotein cholesterol (p < 0.001) at 1 year. Upon multivariate logistic regression analysis, gastrectomy [odds ratio (OR) = 7.77, 95% confidence interval (CI) = 2.05-35.89], diuretic use (OR = 3.76, 95% CI = 1.14-13.98), and lower 24-h total diastolic BP before treatment (OR = 0.90, 95% CI = 0.82-0.96) were predictive of remission of hypertension after adjusting for percent weight. CONCLUSIONS: In early gastric cancer survivors with hypertension, gastrectomy resulted in better BP control than did ESD, which may be due to the gastrectomy itself, beyond weight loss. Therefore, it should be remembered that the adequate reduction of antihypertensives may be necessary in early gastric cancer survivors after gastrectomy.

Clinical characteristics and surgical outcomes of internal hernia after gastrectomy in gastric cancer patients: retrospective case control study.

BACKGROUND: Although the internal hernia is rare after gastric cancer surgery, it is a serious complication, and prompt surgical treatment is essential. However, internal hernia has not been studied because of low incidence and difficulty of diagnosis. This study investigated the clinical characteristics and proper management of internal hernia after gastrectomy. METHODS: From June 2001 to June 2016, patients who underwent gastrectomy, either open or laparoscopic (robotic) surgery, with potential internal hernia defect were enrolled. The hernia defect was not closed in any of the enrolled patients. The clinicopathological data of internal hernia patients were compared to patients without internal hernia to identify risk factors. Surgical outcomes of internal hernia were compared between patients who underwent early and late intervention group according to time interval from symptom onset to operation. RESULTS: Of 5777 patients who underwent gastrectomy with possible internal hernia, 24 (0.4%) underwent emergency or scheduled surgery for internal hernia. Internal hernia through the Petersen space was observed in 15 cases, and through the jejunojejunostomy mesenteric defect in 9 cases. Low body mass index (odds ratio [OR] 4.403, p = 0.003) and laparoscopic approach (OR 6.930 p < 0.001) were statistically significant factors in multivariate analysis. Postoperative complication rate (16.7% vs. 50% p = 0.083) and mortality rate (8.3% vs. 25.0% p = 0.273) were slightly higher in the late intervention group. CONCLUSIONS: Although internal hernia is a rare complication, it is difficult to diagnose and cause serious complications. To prevent internal hernia, the necessity of hernia defect closure should be investigated in the further studies. Early surgical treatment is necessary when it is suspected.

Laparoscopy-assisted versus Open D2 Distal Gastrectomy for Advanced Gastric Cancer: Results From a Randomized Phase II Multicenter Clinical Trial (COACT 1001).

OBJECTIVE: This randomized, phase II, multicenter clinical trial was conducted to evaluate the feasibility of laparoscopy-assisted distal gastrectomy (LADG) with D2 lymph node dissection compared with open distal gastrectomy (ODG) for the treatment of advanced gastric cancer (AGC). SUMMARY OF BACKGROUND DATA: D2 lymph node dissection has been accepted as standard treatment for AGC. Although LADG is widely performed in early gastric cancer (EGC), the feasibility of LADG in AGC has not been proven yet. METHODS: Patients with cT2-T4a and cN0-2 (AJCC 7 staging system) distal gastric cancer were randomly but not blindingly assigned to LADG or ODG groups using fixed block sizes with a 1:1 allocation ratio. The primary endpoint was the noncompliance rate of the lymph node dissection, which was used to evaluate feasibility. Secondary endpoints included 3-year disease-free survival (DFS), 5-year overall survival, complications, and surgical stress response. RESULTS: Between June 2010 and October 2011, 204 patients enrolled and underwent either LADG (n = 105) or ODG (n = 99). Of these, 196 patients (100 in LADG and 96 in ODG) were included in the intention-to-treat analysis. There were no significant differences in the overall noncompliance rate of lymph node dissection between LADG and ODG groups (47.0% and 43.2%, respectively; P = 0.648). In the subgroup analysis, the noncompliance rate in the LADG group was significantly higher than the ODG group for clinical stage III disease (52.0% vs 25.0%, P = 0.043). No difference was found in the 3-year DFS rate between the groups (LADG, 80.1%; ODG, 81.9%; P = 0.448). Differences in postoperative complication rates and surgical stress response were found to be insignificant between the 2 arms. CONCLUSIONS: LADG was feasible for AGC treatment based on the noncompliance rate of D2 lymph node dissection. Subgroups analysis data suggest that further studies are needed for stage III gastric cancer.

Effect of total number of harvested lymph nodes on survival outcomes after curative resection for gastric adenocarcinoma: findings from an eastern high-volume gastric cancer center.

BACKGROUND: Greater lymph node retrieval in gastric cancer improves staging accuracy and may improve survival from increased clearance of nodal micrometastasis. This retrospective cohort study investigated if more lymph nodes removed in gastric cancer increases survival and if such effect is stage-specific due to differential risks of nodal micrometastasis and systemic disease. METHODS: The prospectively collected database of curatively resected gastric cancer patients in National Cancer Center, South Korea between 2000 and 2009 was reviewed. Disease-free survival (DFS) and overall survival (OS) for all patients and for each stage according to number of lymph nodes examined (1-30, 31-45, > 45) were analyzed. RESULTS: Of 4049 patients, 96.6% and 98.4% underwent D2 (perigastric and extragastric) lymphadenectomy and had ≥ 15 lymph nodes examined. Mean number of nodes examined was 43. Five-year OS & DFS rates were 83.3% and 80.7%. Patients with > 45 nodes examined had significantly lower DFS (p = 0.002) and OS (p = 0.007) compared to those with 1-30 and 31-45 nodes. However, proportion of patients with > 45 nodes examined increased with stage (p = 0.0005). Per stage, there was no significant difference in DFS and OS according to number of nodes examined except for stage IIIA favoring more nodes (p = 0.018 and p = 0.044, respectively). Similar trend was seen in stage IIB. Number of examined nodes positively correlated with number of pathologic nodes for all patients (r = 0.144, p < .001) but not for stage IIB and IIIA. Number of nodes examined was a significant survival predictor in stage IIIA. CONCLUSION: Greater lymph node harvest showed improved survival in intermediate-stage gastric cancer.

The distribution pattern of metastatic lymph nodes after non-curative endoscopic resection in early gastric cancer.

BACKGROUND AND OBJECTIVES: Additional surgery should be done after non-curative endoscopic resection (ER) in early gastric cancer (EGC) due to the risk of lymph node metastasis (LNM). However, the distribution pattern of LNM in these patients is complicated and unpredictable. The aim of this study is to identify any different distribution patterns of LNM in patients with EGC who underwent additional surgery after non-curative (ER) comparing to those without ER. METHODS: Patients who underwent surgery for EGC between 2001 and 2016 were included. Enrolled patients were divided into two groups, those who underwent additional surgery after non-curative ER and those who underwent direct surgery without a history of ER. Demographics, tumor characteristics and LNM distribution pattern were analyzed. RESULTS: Among 4295 patients with EGC, 404 patients had a history of preoperative ER, and 3891 patients did not. After the application of exclusion criteria, 23 (7.1%) of 322 patients undergoing additional surgery had LNM. The additional surgery group showed less LNM, fewer nodal stations and more restricted distribution pattern of LNM. CONCLUSIONS: The distribution pattern of LNM in EGC is complicated. However, more restricted locoregional LNM could be expected in cases of additional surgery after non-curative ER than after direct surgery.

Body mass index and mortality in patients with gastric cancer: a large cohort study.

BACKGROUND: The effects of obesity on prognosis in gastric cancer are controversial. AIMS: To evaluate the association between body mass index (BMI) and mortality in patients with gastric cancer. METHODS: A single-institution cohort of 7765 patients with gastric cancer undergoing curative gastrectomy between October 2000 and June 2016 was categorized into six groups based on BMI: underweight (< 18.5 kg/m2), normal (18.5 to < 23 kg/m2), overweight (23 to < 25 kg/m2), mildly obese (25 to < 28 kg/m2), moderately obese (28 to < 30 kg/m2), and severely obese (≥ 30 kg/m2). Hazard ratios (HRs) for overall survival (OS) and disease-specific survival (DSS) were calculated using Cox proportional hazard models. RESULTS: We identified 1279 (16.5%) all-cause and 763 (9.8%) disease-specific deaths among 7765 patients over 83.05 months (range 1.02-186.97) median follow-up. In multivariable analyses adjusted for statistically significant clinicopathological characteristics, preoperative BMI was associated with OS in a non-linear pattern. Compared with normal-weight patients, underweight patients had worse OS [HR 1.42; 95% confidence interval (CI) 1.15-1.77], whereas overweight (HR 0.84; 95% CI 0.73-0.97), mildly obese (HR 0.77; 95% CI 0.66-0.90), and moderately obese (HR 0.77; 95% CI 0.59-1.01) patients had better OS. DSS exhibited a similar pattern, with lowest mortality in moderately obese patients (HR 0.58; 95% CI 0.39-0.85). Spline analysis showed the lowest all-cause mortality risk at a BMI of 26.67 kg/m2. CONCLUSION: In patients undergoing curative gastric cancer surgery, those who were overweight or mildly-to-moderately obese (BMI 23 to < 30 kg/m2) preoperatively had better OS and DSS than normal-weight patients.