Does remnant gastric cancer really differ from primary gastric cancer? A systematic review of the literature by the Task Force of Japanese Gastric Cancer Association

Comprehensive comparison of technical performance, surgical outcomes, and oncologic prognosis between remnant gastric cancer and primary upper-third gastric cancer in the era of minimally invasive surgery: A pooled analysis of 3 prospective trials

BACKGROUND AND OBJECTIVE

To compare the technical performances and short- and long-term outcomes of laparoscopic total gastrectomy for remnant gastric cancer and primary upper gastric cancer.

METHODS

This prospective study (FUGES-004 study) enrolled 50 remnant gastric cancer patients who underwent laparoscopic total gastrectomy at Fujian Medical University Union Hospital between June 2016 and June 2020 (ClinicalTrials.gov identifier: NCT02792881). Propensity score matching (1:2) was used to select upper gastric cancer patients who underwent laparoscopic total gastrectomy in the FUGES-001 and FUGES-002 studies. Technical performance was assessed using the General Error Reporting Tool, Objective Structured Assessment of Technical Skills (OSATS), and Intraoperative Complication Classification.

RESULTS

After matching, 46 remnant gastric cancer and 92 upper gastric cancer patients were included in the final analysis. Abdominal adhesions in the epigastrium, central abdomen, and bowel-to-bowel regions were more severe in the remnant gastric cancer group (P < .001). The remnant gastric cancer group had more technical errors and intraoperative adverse events (especially grade I bleeding) during surgery (P < .05). However, the Objective Structured Assessment of Technical Skills scores were comparable between the remnant gastric cancer and upper gastric cancer groups (30.8 vs 31.0, P = .799). Although the severe postoperative complication rates were similar between the 2 groups (P = .333), the postoperative complication rate was significantly higher in the remnant gastric cancer group (28.3% vs 7.6%, P = .001). Additionally, the long-term oncologic outcomes (including 3-year disease-free survival, overall survival, and recurrence pattern) were comparable between the remnant gastric cancer and upper gastric cancer groups (log-rank P > .05).

CONCLUSIONS

Although the long-term oncologic outcomes were comparable between the groups, the remnant gastric cancer group had more intraoperative errors and adverse events and higher postoperative complication rates than the upper gastric cancer group. For complex remnant gastric cancer cases, laparoscopic total gastrectomy may serve as an effective therapeutic option. However, experienced surgeons at high-volume centers should exercise caution when performing laparoscopic total gastrectomy and implement more rigorous perioperative management strategies.

Residual gastric cancer with a mixed small cell neuroendocrine and keratinizing squamous cell carcinoma: A case report

BACKGROUND

Despite advancements in early detection and treatment, the prognosis and histological types for residual gastric cancer (GC) remains poor.

CASE SUMMARY

This case report presents a rare occurrence of residual GC featuring a combination of small cell neuroendocrine carcinoma (SCNEC) and squamous cell carcinoma (SCC) in a 60-year-old male patient. The patient, with a history of Billroth II gastrectomy for duodenal ulcer bleeding, presented with gastrointestinal bleeding. Preoperative computed tomography and positron emission tomography-computed tomography indicated adenocarcinoma with tumor and abdominal lymph node metastasis. The patient underwent laparoscopic total gastrectomy and lymph node dissection for residual GC. Histological examination of the resected tumor confirmed the presence of both SCNEC and SCC. Postoperatively, the patient underwent adjuvant chemotherapy four times. Two years later, the patient was found to occur esophageal cancer and was performed a small bowel stoma and radical esophagectomy.

CONCLUSION

In this case report, we detail a rare instance of residual GC with mixed SCNEC and SCC, emphasizing the complexity of diagnosis and treatment, and the need for ongoing research.

Evaluating the Need for Additional Surgery After Non-Curative Endoscopic Resection in Patients with Remnant Gastric Cancer

PURPOSE

Completion total gastrectomy is considered an additional treatment after non-curative endoscopic resection for remnant gastric cancer. However, its high invasiveness remains a concern. This study aimed to assess the necessity of additional surgery after non-curative endoscopic submucosal dissection in patients with remnant gastric cancer.

METHODS

This study included patients who underwent non-curative endoscopic submucosal dissection for remnant gastric cancer between September 2002 and January 2018. The eCura system was used to stratify the risk of lymph node metastasis into low, intermediate, or high. The overall survival, disease-specific survival, and long-term clinical course were analyzed.

RESULTS

Among the 46 patients analyzed, 15 underwent additional completion total gastrectomy, whereas 31 were only followed up. Within a median follow-up period of 62.5 months, the additional surgery and follow-up groups showed 5-year overall survival rates of 79.4% and 76.8% (P = 0.93) and disease-specific survival rates of 92.9% and 92.7% (P = 0.98). A total of 19 low-, 8 intermediate-, and 4 high-risk patients in the follow-up group achieved 5-year disease-specific survival rates of 100%, 100%, and 33.3%. Significant differences were observed in the disease-specific survival between the low- and high-risk patients (P < 0.001) and between the intermediate- and high-risk patients (P = 0.02).

CONCLUSION

Risk stratification using the eCura system allows for individualized treatment decisions, with follow-up being a viable option for low- and intermediate-risk patients and additional surgery recommended for high-risk patients after non-curative endoscopic submucosal dissection for remnant gastric cancer.

SURGICAL TREATMENT OF GASTRIC STUMP CANCER: A COHORT STUDY OF 51 PATIENTS

BACKGROUND

Gastric stump neoplasia is defined as a neoplasia that arises in the gastric remnant after at least 5 years of interval from the first gastric resection.

AIMS

The aim of this study was to analyze 51 patients who underwent total and subtotal gastrectomy and multi-visceral resections in patients with gastric stump cancer.

METHODS

The hospital records of 51 patients surgically treated for gastric stump cancer between 1989 and 2019 were reviewed. The following data were analyzed: sex, age group, the interval between the first surgery and the diagnosis of gastric stump cancer, location of the ulcer that motivated the gastrectomy, type of reconstruction, tumor resectability, surgery performed, reconstruction of the digestive tract, associated surgical procedures, postoperative complications using the Clavien-Dindo classification, disease staging, and survival.

RESULTS

There were 43 (83.3%) men, with a mean age of 66.9 years. The mean interval between the initial gastrectomy and surgery for the treatment of gastric stump neoplasia was 34.7 years. All had previously undergone Billroth II reconstruction. Most patients underwent total gastrectomy (35 cases - 68.6%), followed by subtotal gastrectomy (6 cases - 11.8%), and the remainder were considered unresectable (10 patients - 19.6%), undergoing jejunostomy for nutritional support. Multi-visceral resections consisted of splenectomies, cholecystectomies, hepatectomies, partial colectomies, pancreatectomies, enterectomies, and nephrectomies. Among the patients who had the lesion resected, the mean follow-up time was 34.2 months (standard deviation: 47.6 months), the overall survival at 3 years was 43.6%, and the survival at 5 years was 29.7%.

CONCLUSION

The treatment of gastric stump neoplasia is still challenging and difficult, and personalized follow-up strategies should be focused on high-risk patients, offering opportunities for early intervention, better clinical outcomes, and long-term survival.

Impact of Lymphocyte/Monocyte Ratio on Outcomes in Patients with Remnant Gastric Cancer After Gastrectomy

Background

The inflammatory response plays a crucial role in tumor development. Inflammatory markers are recognized prognostic factors in many types of cancer, including gastric cancer. However, the correlation between inflammatory markers and prognosis in remnant gastric cancer (RGC) remains unclear. The aim of this study was to evaluate the importance of inflammatory markers as a prognostic factor in patients who underwent gastrectomy for RGC.

Methods

This multicenter retrospective study involved 107 patients with RGC who underwent curative gastrectomy at 10 institutions in Japan between January 2000 and December 2016. Both overall survival (OS) and relapse-free survival (RFS) were analyzed.

Results

Receiver operating characteristic analyses indicated that the lymphocyte/monocyte ratio (LMR) had a higher area under the curve compared with other potential prognostic factors. Patients were categorized into high- and low LMR groups by the optimal LMR cutoff value. Preoperative LMR was significantly correlated with reconstruction way after the primary surgery (p=0.032) and lymphatic invasion (p=0.046). OS and RFS were significantly worse in the low- vs high LMR groups. Low LMR, T3 or deeper tumor invasion, and low body mass index were independent prognostic factors for OS and RFS.

Conclusion

Preoperative low LMR is associated with poor OS and RFS in patients who undergo gastrectomy for RGC.

Management challenges and the role of adjuvant chemotherapy in remnant gastric cancer: an analysis of 313 patients from the KEGG multicenter observational study

BACKGROUND

Clinical findings and postoperative follow-up data on remnant gastric cancer (RGC) are limited due to its rarity. Additionally, the preoperative staging, radical surgery, and managing recurrence in RGC present significant clinical challenges.

METHODS

We analyzed the clinicopathological findings, adjuvant chemotherapy, and patterns of postoperative recurrence of 313 consecutive patients who underwent curative surgery for RGC at 17 Japanese institutions. This study investigated the optimal management of RGC and the impact of adjuvant chemotherapy (AC) on recurrence-free survival (RFS).

RESULTS

Pathological stages I, II, and III were observed in 55.9% (N = 175), 24.9% (N = 78), and 19.2% (N = 60) of the patients, respectively. The overall concordance rate between clinical and pathological T staging was 58.3%, with a clinical T4 sensitivity of 41.4% for diagnosing pathological T4. During the median follow-up period of 4.6 years, disease recurrence occurred in 24.3% of patients. Most recurrences (over 80%) occurred within 2.5 years, and 96.1% within 5 years after RGC surgery. Peritoneal recurrence was the most common in patients with advanced RGC, accounting for 14.1% in stage II and 28.3% in stage III. Multivariable regression analysis showed that AC was significantly associated with a longer RFS, with a hazard ratio of 0.45 (95% confidence interval: 0.26-0.76).

CONCLUSIONS

Our study underscores the importance of early detection, accurate preoperative staging, and postoperative surveillance in managing advanced RGC cases. Despite some limitations, our findings indicate that AC may provide survival benefits comparable to those seen in primary gastric cancer.

Epstein-Barr Virus and Clinico-Endoscopic Characteristics of Gastric Remnant Cancers Compared to Proximal Non-Remnant Cancers: A Population-Based Study

Epstein-Barr virus (EBV) is associated with 5-10% of gastric cancers and is recognized as a distinct molecular subtype. EBV positivity is particularly high in gastric remnant cancer (GRC), which may inform the mode of clinical presentation and findings at endoscopy. Most data are from the East, and the question remains how this applies to a Western cohort. We conducted a population-based study in Central Norway, 2001-2016. Patients with GRC (n = 78) and patients with non-GRC proximally located cancer and available tissue for EBV status (n = 116, control group) were identified from the Norwegian Cancer Registry. Relevant data were collected from the individual patient journals. EBV status was assessed using in situ hybridization. The median latency time from the distal gastrectomy to GRC was 37.6 (range 15.7-68.0) years. GRC more often presented with GI bleeding, 31.0% vs. 16.1%, p = 0.017, and at endoscopy more seldom with an ulcer, 19.7% vs. 38.2%, p = 0.012, or a tumour, 40.8% vs. 66.4%, p < 0.001. For GRC, 18.7% were EBV-positive compared to 6.0% among the controls, p = 0.006. EBV status was not associated with patient age, sex, or Lauren histological type. No difference in long-term survival rates between GRC and controls was found or between EBV-positive vs. -negative GRCs. In conclusion, a higher proportion of GRC cases, compared to controls, are EBV positive, indicating different causative factors. The mode of clinical presentation and findings at endoscopy were more subtle in the patients with GRC.

Identification of prognostic signatures in remnant gastric cancer through an interpretable risk model based on machine learning: a multicenter cohort study

OBJECTIVE

The purpose of this study was to develop an individual survival prediction model based on multiple machine learning (ML) algorithms to predict survival probability for remnant gastric cancer (RGC).

METHODS

Clinicopathologic data of 286 patients with RGC undergoing operation (radical resection and palliative resection) from a multi-institution database were enrolled and analyzed retrospectively. These individuals were split into training (80%) and test cohort (20%) by using random allocation. Nine commonly used ML methods were employed to construct survival prediction models. Algorithm performance was estimated by analyzing accuracy, precision, recall, F1-score, area under the receiver operating characteristic curve (AUC), confusion matrices, five-fold cross-validation, decision curve analysis (DCA), and calibration curve. The best model was selected through appropriate verification and validation and was suitably explained by the SHapley Additive exPlanations (SHAP) approach.

RESULTS

Compared with the traditional methods, the RGC survival prediction models employing ML exhibited good performance. Except for the decision tree model, all other models performed well, with a mean ROC AUC above 0.7. The DCA findings suggest that the developed models have the potential to enhance clinical decision-making processes, thereby improving patient outcomes. The calibration curve reveals that all models except the decision tree model displayed commendable predictive performance. Through CatBoost-based modeling and SHAP analysis, the five-year survival probability is significantly influenced by several factors: the lymph node ratio (LNR), T stage, tumor size, resection margins, perineural invasion, and distant metastasis.

CONCLUSIONS

This study established predictive models for survival probability at five years in RGC patients based on ML algorithms which showed high accuracy and applicative value.

Lymphovascular invasion is associated with poor long-term outcomes in patients with pT1N0-3 or pT2-3N0 remnant gastric cancer: a retrospective cohort study

BACKGROUND

Lymphovascular invasion (LVI) is a poor prognostic factor in various malignancies. However, its prognostic effect in remnant gastric cancer (RGC) remains unclear. We examined the correlation between LVI and disease prognosis in patients with T1N0-3 or T2-3N0 RGC in whom adjuvant chemotherapy was not indicated and a treatment strategy was not established.

METHODS

We retrospectively analyzed patients with T1N0-3 and T2-3N0 RGC who underwent curative surgery at the Kyoto Prefectural University of Medicine between 1997 and 2019 and at the Kyoto Chubu Medical Center between 2009 and 2019.

RESULTS

Fifteen of 38 patients (39.5%) with RGC were positive for LVI. Patients with LVI had a significantly poorer prognosis for both overall survival ([OS]: P = 0.006) and recurrence-free survival ([RFS]: P = 0.001) than those without LVI. Multivariate analyses using the Cox proportional hazards model revealed LVI as an independent prognostic factor affecting OS (P = 0.024; hazard ratio 8.27, 95% confidence interval:1.285-161.6) and RFS (P = 0.013; hazard ratio 8.98, 95% confidence interval:1.513-171.2).

CONCLUSIONS

LVI is a prognostic factor for patients with T1N0-3 or T2-3N0 RGC. Evaluating LVI may be useful for determining treatment strategies for RGC.

Gastric remnant cancer and long-term survival in Central Norway 2001 to 2016 - A population-based study

INTRODUCTION

Gastric remnant cancer (GRC) has been defined as a distinct clinical entity and is reported to account for 1-8% of all gastric cancers. We aimed to characterize GRC patients and assess survival in a Western population.

METHODS

Retrospective population-based cohort study including 1217 patients diagnosed with gastric adenocarcinoma in Central Norway 2001-2016. GRCs (n = 78) defined as adenocarcinomas arising in the residual stomach after distal gastrectomy were compared to non-GRC (n = 1139) and to proximal non-GRC (n = 595).

RESULTS

78 (6.4 %) gastric cancers were GRC. The annual number and proportion of GRC declined during the study period (p = 0.003). Median latency from distal gastrectomy to GRC diagnosis was 37.6 years (15.7-68.0) and previous Billroth II reconstruction was most common (87.7%). Compared to controls, GRC patients were more frequently males (83.3%), diagnosed in earlier TNM stages and were older at diagnosis. A smaller proportion of GRC patients received perioperative or palliative chemotherapy, but the R0/R1resection rate of 41.0% was no different from non-GRC patients. Overall median survival for GRC patients irrespective of treatment was 7.0 months, which did not differ from non-GRCs or proximal non-GRC. In multivariate analyses TNM stage and age were independently associated with mortality, whereas GRC per se was not.

CONCLUSIONS

Numbers of GRCs declined during the study period, but the latency between distal gastrectomy and GRC diagnosis was long. GRC patients were more frequently male and older than other gastric cancer patients. GRC was not independently associated with survival after adjusting for TNM stage and tumor location.

Does gastric stump cancer really differ from primary proximal gastric cancer? A multicentre, propensity score matching-used, retrospective cohort study

BACKGROUND

Although the location of proximal cancer of the remnant stomach is the same as that of primary proximal cancer of the stomach, its clinical characteristics and prognosis are still controversial.

AIM

To evaluate the clinicopathological features and prognosis factors of gastric stump cancer (GSC) and primary proximal gastric cancer (PGC).

METHODS

From January, 2005 to December, 2016, 178 patients with GSC and 957 cases with PGC who received surgical treatment were enrolled. Patients in both groups underwent 1:1 propensity score matching analysis, and both clinical and pathological data were systematically collected for statistical purposes. Quality of life was evaluated by the C30 and STO22 scale between GSC-malignant (GSC following gastric cancer) and GSC-benign (GSC following benign lesions of the stomach).

RESULTS

One hundred and fifty-two pairs were successfully matched after propensity score matching analysis. Of the 15 demographic and pathological variables collected, the analysis further revealed that the number of lymph nodes and positive lymph nodes were different prognostic and clinicopathological factors between PGC and GSC. Univariate and multivariate analyses showed that gender, differentiation degree and tumor-node-metastasis stage were independent risk factors for patients with GSC. Gender, vascular invasion, differentiation degree, depth of infiltration, positive lymph nodes, and tumor-node-metastasis stage were independent risk factors for patients with PGC. The 5-year overall survival and cancer-specific survival of patients with GSC were significantly lower than those in the PGC group, the scores for overall quality of life in the GSC-malignant group were lower than the GSC-benign, and the differences were statistically significant.

CONCLUSION

The differences in clinicopathological characteristics between GSC and PGC were clarified, and PGC had a better prognosis than GSC.

Indocyanine green fluorescence imaging-guided versus conventional laparoscopic lymphadenectomy for gastric cancer: long-term outcomes of a phase 3 randomised clinical trial

Indocyanine green (ICG) fluorescence imaging-guided lymphadenectomy has been demonstrated to be effective in increasing the number of lymph nodes (LNs) retrieved in laparoscopic gastrectomy for gastric cancer (GC). Previously, we reported the primary outcomes and short-term secondary outcomes of a phase 3, open-label, randomized clinical trial (NCT03050879) investigating the use of ICG for image-guided lymphadenectomy in patients with potentially resectable GC. Patients were randomly (1:1 ratio) assigned to either the ICG or non-ICG group. The primary outcome was the number of LNs retrieved and has been reported. Here, we report the primary outcome and long-term secondary outcomes including three-year overall survival (OS), three-year disease-free survival (DFS), and recurrence patterns. The per-protocol analysis set population is used for all analyses (258 patients, ICG [n = 129] vs. non-ICG group [n = 129]). The mean total LNs retrieved in the ICG group significantly exceeds that in the non-ICG group (50.5 ± 15.9 vs 42.0 ± 10.3, P < 0.001). Both OS and DFS in the ICG group are significantly better than that in the non-ICG group (log-rank P = 0.015; log-rank P = 0.012, respectively). There is a difference in the overall recurrence rates between the ICG and non-ICG groups (17.8% vs 31.0%). Compared with conventional lymphadenectomy, ICG guided laparoscopic lymphadenectomy is safe and effective in prolonging survival among patients with resectable GC.

The epigenetic modifier lysine methyltransferase 2C is frequently mutated in gastric remnant carcinoma

Gastric remnant carcinoma (GRC), which occurs in the stomach after partial gastrectomy, is a rare and aggressive form of gastric adenocarcinoma (GAC). Comprehensive profiling of genomic mutations in GRC could provide the basis for elucidating the origin and characteristics of this cancer. Herein, whole-exome sequencing (WES) was performed on 36 matched tumor-normal samples from patients with GRC and identified recurrent mutations in epigenetic modifiers, notably KMT2C, ARID1A, NSD1, and KMT2D, in 61.11% of cases. Mutational signature analysis revealed a low frequency of microsatellite instability (MSI) in GRC, which was further identified by MSIsensor, MSI-polymerase chain reaction, and immunohistochemistry analysis. Comparative analysis demonstrated that GRC had a distinct mutation spectrum compared to that of GAC in The Cancer Genome Atlas samples, with a significantly higher mutation rate of KMT2C. Targeted deep sequencing (Target-seq) of an additional 25 paired tumor-normal samples verified the high mutation frequency (48%) of KMT2C in GRC. KMT2C mutations correlated with poor overall survival in both WES and Target-seq cohorts and were independent prognosticators in GRC. In addition, KMT2C mutations were positively correlated with favorable outcomes in immune checkpoint inhibitor-treated pan-cancer patients and associated with higher intratumoral CD3+ , CD8+ tumor-infiltrating lymphocyte counts, and PD-L1 expression in GRC samples (p = 0.018, 0.092, 0.047, 0.010, and 0.034, respectively). Our dataset provides a platform for information and knowledge mining of the genomic characteristics of GRC and helps to frame new therapeutic approaches for this disease.

Propensity Score Matching Analysis of the Safety of Completion Total Pancreatectomy for Remnant Pancreatic Tumors Versus that of Initial Total Pancreatectomy for Primary Pancreatic Tumors

BACKGROUND

The safety and feasibility of completion total pancreatectomy (TP) for remnant pancreatic neoplasms remain controversial and are rarely compared with that of initial TP. Thus, we aimed to compare the safety of these two procedures inducing a pancreatic state.

METHODS

Patients who underwent TP for pancreatic neoplasms between 2006 and 2018 at our institution were included in this study. Tumor pathologies were classified into three subgroups according to survival curves. We used 1:1 propensity score matching (PSM) to analyze age, sex, Charlson Comorbidity Index, and tumor stage. Finally, we analyzed the primary outcome Clavien-Dindo classification (CDC) grade, risks of other safety-related outcomes, and the survival rate of patients with invasive cancer.

RESULTS

Of 54 patients, 16 underwent completion TP (29.6%) and 38 (70.4%) underwent initial TP. Before PSM analysis, age and Charlson Comorbidity Index were significantly higher, and T category and stage were significantly lower for the completion TP group. Upon PSM analysis, these two groups were equivalent in CDC grade [initial TP vs. completion TP: 71.4% (10/14) vs. 78.6% (11/14); p = 0.678] and other safety-related outcomes. Additionally, while the overall survival and recurrence-free survival of patients with invasive cancer were not significantly different between these two groups, the T category and stage tended to be remarkably severe in the initial TP group.

CONCLUSIONS

PSM analysis for prognostic factors showed that completion TP and initial TP have similar safety-related outcomes that can be used as a decision-making reference in the surgery of pancreatic tumors.

Appraisal of gastric stump carcinoma and current state of affairs

Gastric stump carcinoma, also known as remnant gastric carcinoma, is a malignancy arising in the remnant stomach following gastrectomy for a benign or malignant condition. Enterogastric reflux and preexisting risk factors in a patient with gastric cancer are the major contributors to the development of gastric stump carcinoma. The occurrence of gastric stump carcinoma is time-dependent and seen earlier in patients operated on for malignant rather than benign diseases. The tumor location is predominantly at the anastomotic site towards the stomach. However, it can occur anywhere in the remnant stomach. The pattern of lymph node involvement and the type of surgery required is distinctly different compared to primary gastric cancer. Gastric stump carcinoma is traditionally considered a malignancy with a dismal outcome. However, recent advances in diagnostic and therapeutic strategies have improved outcomes. Recent advances in molecular profiling of gastric stump carcinoma have identified distinct molecular subtypes, thereby providing novel therapeutic targets. Also, reports of gastric stump carcinoma following pancreatoduodenectomy and bariatric surgery highlight the need for more research to standardize the diagnosis, staging, and treatment of these tumors. The present review aims to provide an overview of gastric stump carcinoma highlighting the differences in clinicopathological profile and management compared to primary gastric carcinoma.

Incidence of Metachronous Remnant Gastric Cancer after Proximal Gastrectomy with the Double-flap Technique (rD-FLAP-rGC Study): A Multicenter, Retrospective Study

BACKGROUND

Although proximal gastrectomy (PG) with the double-flap technique (DFT) is a function-preserving surgery that prevents esophagogastric reflux, there is a risk of developing metachronous remnant gastric cancer (MRGC). Moreover, details of MRGC and appropriate postoperative follow-up after PG with DFT are unclear.

METHODS

We reviewed the medical records of 471 patients who underwent PG with DFT for cancer in a preceding, multicenter, retrospective study (rD-FLAP Study). We investigated the incidence of MRGC, frequency of follow-up endoscopy, and eradication of Helicobacter pylori (H. pylori) infection.

RESULTS

MRGC was diagnosed in 42 (8.9%) of the 471 patients, and 56 lesions of MRGC were observed. The cumulative 5- and 10-year incidence rates were 5.7 and 11.4%, respectively. There was no clinicopathological difference at the time of primary PG between patients with and without MRGC. Curative resection for MRGC was performed for 49 (88%) lesions. All patients with a 1-year, follow-up, endoscopy interval were diagnosed with early-stage MRGC, and none of them died due to MRGC. Overall and disease-specific survival rates did not significantly differ between patients with and without MRGC. The incidence rate of MRGC in the eradicated group after PG was 10.8% and that in the uneradicated group was 19.6%, which was significantly higher than that in patients without H. pylori infection at primary PG (7.6%) (p = 0.049).

CONCLUSIONS

The incidence rate of MRGC after PG with DFT was 8.9%. Early detection of MRGC with annual endoscopy provides survival benefits. Eradicating H. pylori infection can reduce the incidence of MRGC.

Meso-jejunal lymph node dissection has a survival benefit in patients with remnant gastric cancer

BACKGROUND

Clinical benefits of the meso-jejunal lymph node (MJLN) dissection in remnant gastric cancer (RGC) patients have not been fully established. Hence, in this retrospective study, we evaluated the survival benefit of MJLN dissection and prognostic significance of MJLN metastasis in RGC patients who underwent gastrojejunostomy reconstruction after their initial gastrectomy.

METHODS

We retrospectively reviewed 391 patients who underwent surgery for RGC at our institution between 1996 and 2019. Among them, 60 patients had MJLN dissection. The index value of the survival benefit gained by dissection of the MJLN was calculated by multiplying the frequency of metastasis at the MJLN station and the 5-year overall survival rate (5YOS) of patients with metastasis at that station. When the metastatic rate or 5YOS exceeded 10%, dissection was recommended. An index value of dissection greater than 1.0 was considered significant.

RESULTS

Total metastatic rate of MJLN was 35% (n = 21/60). Patients with MJLN metastasis had advanced pathologic stage compared to patients in the no-metastasis group (p < 0.001). In T2-T4 RGC patients, the metastatic rate of MJLN was 48.6% (n = 17/35), and their 5YOS was 28.4%. The calculated index value was 13.8. Also, patients with MJLN metastasis had a poorer overall survival than those without metastasis. MJLN metastasis was an independent prognostic factor of overall survival in multivariate analysis (HR 6.77, 95%CI 2.21-20.79, p = 0.001).

CONCLUSION

MJLN dissection should be considered for advanced RGC patients who underwent gastrojejunostomy after distal gastrectomy during their initial surgery according to the index value.

Pathological and oncological outcomes of pylorus-preserving versus conventional distal gastrectomy in early gastric cancer: a systematic review and meta-analysis

Background

Pylorus-preserving gastrectomy (PPG) is a function-preserving surgery for the treatment of early gastric cancer (EGC) in the middle third of the stomach. According to the literature reports, PPG decreases the incidence of dumping syndrome, bile reflux, gallstone formation, and nutritional deficit compared with conventional distal gastrectomy (CDG). However, the debates about PPG have been dominated by the incomplete lymphadenectomy and oncological safety. We carried out a systematic review and meta-analysis to evaluate the pathological and oncological outcomes of PPG.

Methods

The protocol was registered in PROSPERO under number CRD42022304677. Databases including PubMed, Embase, Web of Science, and the Cochrane Register of Controlled Trials were searched before February 21, 2022. The outcomes included the pooled odds ratios (ORs) for dichotomous variables and weighted mean differences (WMDs) for continuous variables. For all outcomes, 95% confidence intervals (CIs) were calculated. Meta-analysis was performed using STATA software (Stata 14, Stata Corporation, Texas) and Review Manager 5.4.

Results

A total of 4500 patients from 16 studies were included. Compared with the CDG group, the PPG group had fewer lymph nodes harvested (WMD= −3.09; 95% CI −4.75 to −1.43; P < 0.001). Differences in the number of resected lymph nodes were observed at stations No. 5, No. 6, No. 9, and No. 11p. There were no differences in lymph node metastasis at each station. Shorter proximal resection margins (WMD = −0.554; 95% CI −0.999 to −0.108; P = 0.015) and distal resection margins (WMD = −1.569; 95% CI −3.132 to −0.007; P = 0.049) were observed in the PPG group. There were no significant differences in pathological T1a stage (OR = 0.99; 95% CI 0.80 to 1.23; P = 0.88), T1b stage (OR = 1.01; 95% CI 0.81 to 1.26; P = 0.88), N0 stage (OR = 0.97; 95% CI 0.63 to 1.48; P = 0.88), tumor size (WMD = −0.10; 95% CI −0.25 to 0.05; P = 0.187), differentiated carcinoma (OR = 1.04; 95% CI 0.74 to 1.47; P = 0.812) or signet ring cell carcinoma (OR = 1.22; 95% CI 0.90 to 1.64; P = 0.198). No significant differences were observed between the groups in terms of overall survival (HR = 0.63; 95% CI 0.24 to 1.67; P = 0.852) or recurrence-free survival (HR = 0.29; 95% CI 0.03 to 2.67; P = 0.900).

Conclusions

The meta-analysis of existing evidence demonstrated that the survival outcomes of PPG may be comparable to those of CDG. However, fewer lymph nodes at stations in No. 5, No. 6, No. 9, and No. 11p were harvested with PPG. We also found shorter proximal resection margins and distal resection margins for PPG, meaning more remnant stomachs would be preserved in PPG.

Evaluating the optimal treatment strategy for early and advanced remnant gastric cancer

BACKGROUND

This study assessed lymph node metastasis characteristics to investigate the optimal treatment strategy for early and advanced remnant gastric cancer (RGC).

METHODS

Cases of completion gastrectomy for RGC were enrolled. The frequency of lymph node metastasis was investigated, and risk factors for metastasis were identified. The clinical significance of completion gastrectomy in early remnant gastric carcinoma cases was also examined. In advanced cases, 3-year survival was analysed to investigate the prognostic importance of lymph node dissection and splenectomy.

RESULTS

Seventy-nine patients were included. Lymphatic invasion and pathological tumour depth were identified as risk factors for lymph node metastasis. There was no metastasis in the pT1 cases. In advanced cases, the incidence of lymph node #10 and jejunal lymph node metastasis was 8.3-10.0% and 17.6%, respectively. Prognosis was found to be unrelated with splenectomy.

CONCLUSIONS

Lymphatic invasion and pathological T status were identified as risk factors for LN metastasis in RGC. Additional gastrectomy after ESD might not be mandatory for early RGC cases. For advanced RGC cases, splenectomy might not improve patient prognosis, however, lymph node dissection of jejunal and #10 lymph nodes should be considered due to its high incidence of metastasis.

Postoperative Complications and Their Risk Factors of Completion Total Gastrectomy for Remnant Gastric Cancer Following an Initial Gastrectomy for Cancer

PURPOSE

Completion total gastrectomy (CTG) for remnant gastric cancer (RGC) is a technically demanding procedure and associated with increased morbidity. The present study aimed to evaluate postoperative complications and their risk factors following surgery for RGC after initial partial gastrectomy due to gastric cancer excluding peptic ulcer.

MATERIALS AND METHODS

We retrospectively reviewed the data of 107 patients who had previously undergone an initial gastric cancer surgery and subsequently underwent CTG for RGC between March 2002 and December 2020. The postoperative complications were graded using the Clavien-Dindo classification. Logistic regression analyses were used to determine the risk factors for complications.

RESULTS

Postoperative complications occurred in 34.6% (37/107) of the patients. Intra-abdominal abscess was the most common complication. The significant risk factors for overall complications were multi-visceral resections, longer operation time, and high estimated blood loss in the univariate analysis. The independent risk factors were multi-visceral resection (odds ratio [OR], 2.832; 95% confidence interval [CI], 1.094-7.333; P=0.032) and longer operation time (OR, 1.005; 95% CI, 1.001-1.011; P=0.036) in the multivariate analysis. Previous reconstruction type, minimally invasive approach, and current stage were not associated with the overall complications.

CONCLUSIONS

Multi-visceral resection and long operation time were significant risk factors for the occurrence of complications following CTG rather than the RGC stage or surgical approach. When multi-visceral resection is required, a more meticulous surgical procedure is warranted to improve the postoperative complications during CTG for RGC after an initial gastric cancer surgery.

Lymph node distribution in patients with remnant gastric cancer

BACKGROUND

Remnant gastric cancer (RGC) is defined as a carcinoma that develops in the gastric remnant from 5 years after gastrectomy, regardless of the primary gastric disease. The pattern of lymph node dissemination in these patients is not well understood. The present study aims to understand the lymph node distribution of patients with RGC in a single center.

METHODS

In a total of 1380 patients with gastric cancer, between 1998 and 2020, 43 patients operated on for RGC were analyzed. The pattern of lymph node dissemination was evaluated based on the number of dissected lymph node stations, the number of positive lymph node stations, the positivity index at each analyzed station, the number of dissected lymph nodes per patient, and the positivity index per lymph node station.

RESULTS

A mean of 13.0 ± 8.1 lymph nodes were dissected. The incidence of lymph node involvement by dissected station was higher at Stations 19, 11p, 3, 4sb and 7 (50, 40, 37.5, 36 and 31.7%, respectively). Among the positive dissected stations, Station 3 with 52.2%, 4sb with 39.1% and 4sa with 34.8% were the most affected.

CONCLUSION

There was no predilection for lymph node involvement when comparing the lesser and greater gastric curvature. The dissection of Stations 3, 4sb and 4sa is fundamental in surgical treatment with curative purposes. The totalization of gastrectomy with lymphadenectomy of the perigastric and supra-pancreatic stations should be the surgery of choice.

Development of the PERI-Gastric (PEritoneal Recurrence Index) and PERI-Gram (Peritoneal Recurrence Index NomoGRAM) for predicting the risk of metachronous peritoneal carcinomatosis after gastrectomy with curative intent for gastric cancer

BACKGROUND

A model that quantifies the risk of peritoneal recurrence would be a useful tool for improving decision-making in patients undergoing curative-aim gastrectomy for gastric cancer (GC).

METHODS

Five Italian centers participated in this study. Two risk scores were created according to the two most widely used pathologic classifications of GC (the Lauren classification and the presence of signet-ring-cell features). The risk scores (the PERI-Gastric 1 and 2) were based on the results of multivariable logistic regressions and presented as nomograms (the PERI-Gram 1 and 2). Discrimination was assessed with the area under the curve (AUC) of receiver operating curves. Calibration graphs were constructed by plotting the actual versus the predicted rate of peritoneal recurrence. Internal validation was performed with a bootstrap resampling method (1000 iterations).

RESULTS

The models were developed based on a population of 645 patients (selected from 1580 patients treated from 1998 to 2018). In the PERI-Gastric 1, significant variables were linitis plastica, stump GC, pT3-4, pN2-3 and the Lauren diffuse histotype, while in the PERI-Gastric 2, significant variables were linitis plastica, stump GC, pT3-4, pN2-3 and the presence of signet-ring cells. The AUC was 0,828 (0.778-0.877) for the PERI-Gastric 1 and 0,805 (0.755-0.855) for the PERI-Gastric 2. After bootstrap resampling, the PERI-Gastric 1 had a mean AUC of 0.775 (0.721-0.830) and a 95%CI estimate for the calibration slope of 0.852-1.505 and the PERI-Gastric 2 a mean AUC of 0.749 (0.693-0.805) and a 95%CI estimate for the slope of 0.777-1.351. The models are available at www.perigastric.org .

CONCLUSIONS

We developed the PERI-Gastric and the PERI-Gram as instruments to determine the risk of peritoneal recurrence after curative-aim gastrectomy. These models could direct the administration of prophylactic intraperitoneal treatments.

Accuracy of preoperative staging of gastric stump cancer

BACKGROUND

In this study, the accuracy of preoperative staging for gastric stump cancer, which has not been thoroughly investigated since the condition is rare, was investigated using computed tomography and gastroscopic imaging.

METHODS

Between February 1994 and April 2018, 49 patients with gastric stump cancer, following subtotal or total gastrectomy, were reviewed retrospectively. Preoperative diagnoses of clinical T and clinical N categories were compared with post-operative pathological diagnoses (pT and pN categories). Positive predictive values, accuracy, sensitivity and specificity were also evaluated.

RESULTS

The overall accuracy of T staging was 40.8%. The positive predictive value for cT3/T4 was 96.3%, whereas the positive predictive value for cT1/T2 was 72.7%. The overall accuracy for N staging was 61.2%. The positive predictive value of lymph node positive patients was 73.3%. The positive predictive value and sensitivity of over stage II were 96.6% and 84.8%, respectively.

CONCLUSIONS

The accuracy of preoperative diagnosis using both computed tomography and gastroscopy imaging may be feasible for T3/T4 advanced gastric stump cancer, whereas diagnosing T1/2 gastric stump cancer must be carefully considered due to high misdiagnosis rates, relating to depth.

T stage and venous invasion are crucial prognostic factors for long-term survival of patients with remnant gastric cancer: a cohort study

Background

The incidence of remnant gastric cancer (RGC) after distal gastrectomy is 1–5%. However, as the survival rate of patients with gastric cancer improves due to early detection and treatment, more patients may develop RGC. There is no consensus on the surgical and postoperative management of RGC, and the clinicopathological characteristics correlated with the long-term outcomes remain unclear. Therefore, we investigated the clinicopathological factors associated with the long-term outcomes of RGC.

Methods

We included 65 consecutive patients who underwent gastrectomy for RGC from January 2000 to December 2015 at the Osaka Medical and Pharmaceutical University Hospital, Japan. The Kaplan–Meier method was used to create survival curves, and differences in survival were compared between the groups (clinical factors, pathological factors, and surgical factors) using the log-rank test. Multivariate analyses using the Cox proportional hazard model were used to identify factors associated with long-term survival.

Results

No significant differences were noted in the survival rate based on clinical factors (age, body mass index, diabetes mellitus, hypertension, cardiovascular disease, pulmonary complications, liver disease, diet, history of alcohol drinking, and history of smoking) or the type of remnant gastrectomy. Significant differences were noted in the survival rate based on pathological factors and surgical characteristics (intraoperative blood loss, operation time, and the number of positive lymph nodes). Multivariate analysis revealed that the T stage (hazard ratio, 5.593; 95% confidence interval [CI], 1.183–26.452; p = 0.030) and venous invasion (hazard ratio, 3.351; 95% CI, 1.030–10.903; p = 0.045) were significant independent risk factors for long-term survival in patients who underwent radical resection for RGC.

Conclusions

T stage and venous invasion are important prognostic factors of long-term survival after remnant gastrectomy for RGC and may be keys to managing and identifying therapeutic strategies for improving prognosis in RGC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12957-021-02400-5.

Remnant gastric cancer: An ordinary primary adenocarcinoma or a tumor with its own pattern?

BACKGROUND

Remnant gastric cancer (RGC) is defined as a tumor that develops in the stomach after a previous gastrectomy and is generally associated with a worse prognosis. However, there little information available regarding RGCs and their prognostic factors and survival.

AIM

To evaluate the clinicopathological characteristics and prognosis of RGC after previous gastrectomy for benign disease.

METHODS

Patients who underwent curative resection for primary gastric cancer (GC) at our institute between 2009 and 2019 were retrospectively evaluated. All RGC resections with histological diagnosis of gastric adenocarcinoma were enrolled in this study. Primary proximal GC (PGC) who underwent total gastrectomy was selected as the comparison group. Clinical and pathological data were collected from a prospective medical database.

RESULTS

A total of 41 patients with RGC and 120 PGC were included. Older age (P = 0.001), lower body mass index (P = 0.006), hemoglobin level (P < 0.001), and number of resected lymph nodes resected (LN) (P < 0.001) were associated with the RGC group. Lauren type, pathological tumor-node-metastasis, and perioperative morbimortality were similar between RGC and PGC. There was no difference in disease-free survival (P = 0.592) and overall survival (P = 0.930) between groups. LN status was the only independent factor related to survival.

CONCLUSION

RGC had similar clinicopathological characteristics to PGC. Despite the lower number of resected LN, RGC had a similar prognosis.

Molecular and pathological analyses of gastric stump cancer by next-generation sequencing and immunohistochemistry

Gastric stump cancer (GSC) has distinct clinicopathological characteristics from primary gastric cancer. However, the detailed molecular and pathological characteristics of GSC remain to be clarified because of its rarity. In this study, a set of tissue microarrays from 89 GSC patients was analysed by immunohistochemistry and in situ hybridisation. Programmed death ligand 1 (PD-L1) was expressed in 98.9% of tumour-infiltrating immune cells (TIICs) and 6.7% of tumour cells (TCs). Epstein-Barr virus (EBV) was detected in 18 patients (20.2%). Overexpression of human epidermal growth factor receptor 2 and deficiency of mismatch repair (MMR) protein expression were observed in 5.6% and 1.1% of cases, respectively. Moreover, we used next-generation sequencing to determine the gene mutation profiles of a subset of the 50 most recent patients. The most frequently mutated genes were TP53 (42.0%) followed by SMAD4 (18.0%) and PTEN (16.0%), all of which are tumour suppressor genes. A high frequency of PD-L1 expression in TIICs and a high EBV infection rate suggest immune checkpoint inhibitors for treatment of GSC despite a relatively low frequency of deficient MMR gene expression. Other molecular characteristics such as PTEN and SMAD4 mutations might be considered to develop new treatment strategies.

Incidence of Multiple Metachronous Gastric Cancers After Pyloric-Preserving Gastrectomy

AIM

Pylorus-preserving gastrectomy (PPG) is widely used for early gastric cancer located in the middle third of the stomach. The minimization of the extent of gastrectomy may increase the risk of metachronous multiple gastric cancer (MGC). We report the findings of a study that was conducted to evaluate the prevalence of MGC after PPG.

METHODS

The clinical data of 533 patients who underwent PPG for gastric cancer between 1993 and 2018 were reviewed. The clinicopathological characteristics at the time of the primary treatment that were predictive of the development of MGC were explored. The median (range) observation period was 112.4 (8.1-290.7) months.

RESULTS

Metachronous MGC was diagnosed in 33 of the 533 patients. The cumulative 5-year and 10-year event rates were 3.3% and 6.2%, respectively. The patient gender, presence/absence of synchronous MGC and the macroscopic type of the primary gastric cancer were significantly associated with the risk of development of metachronous MGC. Multivariate analysis identified the presence of synchronous MGC (hazard ratio [HR]: 4.828, 95% confidence interval [CI]; 1.611-12.30, p = 0.004) and Type 0-IIa primary gastric cancer (HR 2.810, 95% CI; 1.113-7.090, p = 0.029) as independent factors associated with the risk of development of MGC. All the patients could be treated by surgical or endoscopic resection for the metachronous MGC. Recurrence was observed in one patient.

CONCLUSIONS

There was quite a few incidence of development of metachronous MGC after PPG. Nevertheless, PPG remains reasonable treatment option, if adequate postoperative surveillance can be ensured.

Feasibility and quality of life assessment of laparoscopic proximal gastrectomy using double-tract reconstruction

PURPOSE

As the frequency of cancer in the proximal stomach or around the esophagogastric junction (EGJ) increases worldwide, the use of laparoscopic proximal gastrectomy (LPG) has expanded. This study evaluated the safety of LPG with double-tract reconstruction (LPG-DT) and the resulting quality of life (QOL) of patients.

METHODS

In this retrospective cohort study, we reviewed the data of patients who underwent LPG-DT via linear-stapled esophagojejunostomy for gastric or EGJ cancer between 2013 and 2019, and outcomes were compared with those of laparoscopic total gastrectomy with Roux-en-Y reconstruction (LTG-RY) peMME000372rformed over the same period. Surgical outcomes, changes of nutritional parameters, and chronological QOL as evaluated using the Postgastrectomy Syndrome Assessment Scale (PGSAS-37) questionnaire were compared in the propensity-matched cohorts.

RESULTS

In total, 289 patients (99 LPG-DT and 190 LTG-RY) were eligible and the outcomes were evaluated in the propensity-matched cohorts (n = 75 each). Operative time and the incidence of complications (≥ grade III) were comparable. Reflux esophagitis was more frequent in the LPG-DT group (8.0% vs. 0%), whereas the incidence of anastomotic stricture did not differ. The percentage rates of body weight loss and hemoglobin reduction were lower in the LPG-DT group at any time point within postoperative 2 years but show no statistical differences. In PGSAS-37 (n = 26, n = 23), the diarrhea and quality of ingestion scores were slightly better in the LPG-DT group.

CONCLUSIONS

The present study suggested that our LPG-DT is feasible and safe in appropriately selected patients, and it may provide slightly better outcomes in nutrition and QOL compared with LTG-RY.

Remnant gastric cancer: a neglected group with high potential for immunotherapy

PURPOSE

The importance of targeted therapy and interest in the study of predictive markers in gastric cancer (GC) have increased in recent years with the use of anti-HER2 therapy and immunotherapy with anti-PD1/PD-L1 for microsatellite instability (MSI) and PD-L1 + tumors. However, the behavior of remnant GC (RGC) in this scenario is poorly reported. Thus, this study aims to evaluate the clinicopathological characteristics and prognosis of RGC and its association with the expression of current markers for targeted therapy.

METHODS

All RGC resections performed in a single center from 2009 to 2019 were retrospectively reviewed. As a comparison group, 53 primary proximal GC (PGC) who underwent total D2-gastrectomy were selected. HER2, MSI status and PD-L1 expression were analyzed by immunohistochemistry. Combined Positive Score (CPS) was used to determine PD-L1 positivity.

RESULTS

A total of 40 RGC were included. RGC patients were older (p = 0.001), had lower BMI (p = 0.001) and number of resected lymph nodes (p < 0.001) compared to the PGC. Regarding markers expression, MSI was higher in RGC than PGC (27.5% vs 9.4%, p = 0.022). The frequency of CPS-positive was 32.5% and 26.4% in RGC and PGC, respectively (p = 0.522). HER2 positivity was 17.5% and 22.6% for RGC and PGC, respectively (p = 0.543). In survival analysis, DFS was better for RGC CPS-positive than RGC CPS-negative (p = 0.039) patients. There was no difference in survival considering MSI status.

CONCLUSION

RGC had higher incidence of MSI than PGC, and CPS-positive RGC was associated with better survival. The immunological profile of RGC patients suggests that they would be good candidates for immunotherapy.

Optimal extent of lymph node dissection for remnant advanced gastric carcinoma after distal gastrectomy: a retrospective analysis of more than 3000 patients from the nationwide registry of the Japanese Gastric Cancer Association

BACKGROUND

No guidelines are available for defining the extent of lymph node (LN) dissection in patients with remnant gastric carcinoma (RGC). Hence, this retrospective study aimed to determine the optimal extent of LN dissection in patients with RGC.

METHODS

We retrospectively evaluated the therapeutic outcomes of node dissection for RGC from a nationwide registry. When the metastatic rate or 5-year survival rate exceeded 10%, dissection was recommended. We calculated the dissection index by multiplying the incidence of metastasis at that nodal station by the 5-year survival rate of patients with metastasis at the station. A dissection index of > 1.0 was considered significant.

RESULTS

We included 1133 patients with RGC (T2-T4 tumor) who had undergone distal gastrectomy as the primary surgery for the evaluation of the survival benefit of nodal dissection. Any regional node station was considered significant. When the primary surgery was for malignant disease, the index was high for Nos. 3 (10.2), 7 (9.5), 1 (7.1), and 9 (8.0) nodes. For nodes at the splenic hilum, the index value was 4.4, which was higher than that for the perigastric nodes (Nos. 4sa and 4sb). The index for No. 10 nodes was the highest (10.5) when tumors involved a greater curvature.

CONCLUSIONS

The therapeutic strategy for RGC remains the same, regardless of the histology of the primary disease during the initial surgery. Total gastrectomy and dissection of the perigastric LNs (Nos. 1-4), suprapancreatic LNs (Nos. 7-9 and 11), and LNs at the splenic hilum (No. 10) are justified.

Surveillance Endoscopy Guidelines for Postgastrectomy Patients Based on Risk of Developing Remnant Gastric Cancer

BACKGROUND

Remnant gastric cancer (RGC) has a major impact on the long-term survival of postgastrectomy patients. In this study, we established surveillance endoscopy guidelines for postgastrectomy patients based on the risk of RGC.

PATIENTS AND METHODS

A total of 6365 patients who underwent gastrectomy at Seoul St. Mary's Hospital from September 2005 to June 2018 were retrospectively reviewed; 85 patients were identified as having RGC. We divided the RGC patients into subgroups according to the interval between primary and secondary gastrectomy.

RESULTS

The curative resection rate was significantly lower in patients with an interval of ≤ 5 years versus > 5 years (p = 0.017). RGC developed more frequently after Billroth II reconstruction, and at the anastomotic site, in patients with a > 10- versus ≤ 10-year interval (p = 0.006 and p = 0.014, respectively). Similar results were observed based on the 15-year interval cutoff (p = 0.001 and 0.018, respectively). The 5-year overall survival rate of patients with a ≤ 5-year interval was significantly lower than that of patients with a > 5-year interval (60.0% versus 85.7%, p = 0.015), while overall survival did not differ between the ≤ 10- and > 10-year, or ≤ 15- and 15-year interval groups. RGC incidence showed a decrease after around 20 years postoperatively.

CONCLUSIONS

Thorough endoscopic examination should be conducted for up to 5 years postgastrectomy. Routine annual endoscopic follow-up should be performed for up to 20 years after the primary operation for gastric cancer, to allow for early detection of RGC.

Is subtotal gastrectomy feasible for the treatment of gastric stump cancer located at the anastomotic site after distal gastrectomy for benign lesions?

BACKGROUND

Total gastrectomy (TG) is a widely accepted procedure for treating gastric stump cancer (GSC). However, subtotal gastrectomy (SG) would benefit elective patients with GSC. The aim of this study was to clarify the safety and long-term prognosis of SG in treating GSC after distal gastrectomy for benign lesions.

METHODS

A total of 53 patients with GSC located at the anastomotic site or gastric body between May 1999 and December 2018 at our hospital were included. In total, 21 patients underwent SG, and the remaining 24 patients underwent TG. Clinicopathological data, operative data, and overall survival (OS) were compared.

RESULTS

The operative duration, estimated blood loss volume, and length of hospital stay were similar between the SG and TG groups. The postoperative complications were similar between the two groups, but no cases of anastomotic leakage were noted in the SG group. TG was associated with significantly more retrieved lymph nodes than SG (18.5 ± 11.5 vs. 10.7 ± 9.2; p = 0.017), while the number of metastatic lymph nodes did not differ between the groups (2.9 ± 3.5 vs. 1.9 ± 3.6; p = 0.329). The median survival time in the SG group was 81.0 months (95% confidence interval (CI), 68.906 to 93.094 months), which was similar to the 45.0 months (95% CI, 15.920 to 74.080 months) observed in the TG group (p = 0.236). Both univariate and multivariate analyses showed that tumor location and histological type were prognostic factors, while surgery type was not a prognostic factor. Further stratified analyses according to tumor location revealed that OS was not significantly different between the two groups among patients with tumors located at the anastomotic site, while OS in the TG group was significantly better than that in the SG group among patients with tumors located in the gastric body (p = 0.046).

CONCLUSIONS

The results of the current study indicate that SG is a suitable alternative surgical procedure for GSC located at the anastomotic site after distal gastrectomy for benign lesions. The short-term outcomes and long-term prognoses of SG are comparable with those of TG.

Conditional survival and recurrence of remnant gastric cancer after surgical resection: A multi-institutional study

The present study was designed to evaluate the dynamic survival and recurrence of remnant gastric cancer (RGC) after radical resection and to provide a reference for the development of personalized follow-up strategies. A total of 298 patients were analyzed for their 3-year conditional overall survival (COS3), 3-year conditional disease-specific survival (CDSS3), corresponding recurrence and pattern changes, and associated risk factors. The 5-year overall survival (OS) and the 5-year disease-specific survival (DSS) of the entire cohort were 41.2% and 45.8%, respectively. The COS3 and CDDS3 of RGC patients who survived for 5 years were 84.0% and 89.8%, respectively. The conditional survival in patients with unfavorable prognostic characteristics showed greater growth over time than in those with favorable prognostic characteristics (eg, COS3, ≥T3: 46.4%-83.0%, Δ36.6% vs ≤T2: 82.4%-85.7%, Δ3.3%; P < 0.001). Most recurrences (93.5%) occurred in the first 3 years after surgery. The American Joint Committee on Cancer (AJCC) stage was the only factor that affected recurrence. Time-dependent Cox regression showed that for both OS and DSS, after 4 years of survival, the common prognostic factors that were initially judged lost their ability to predict survival (P > 0.05). Time-dependent logistic regression analysis showed that the AJCC stage independently affected recurrence within 2 years after surgery (P < 0.05). A postoperative follow-up model was developed for RGC patients. In conclusion, patients with RGC usually have a high likelihood of death or recurrence within 3 years after radical surgery. We developed a postoperative follow-up model for RGC patients of different stages, which may affect the design of future clinical trials.

Clinicopathologic features of remnant gastric cancer after curative distal gastrectomy according to previous reconstruction method: a retrospective cohort study

BACKGROUND

Survival rate of patients treated for gastric cancer has increased due to early detection and improvements of surgical technique and chemotherapy. Increase in survival rate has led to an increase in the risk for remnant gastric cancer (RGC). The purpose of this study was to investigate clinicopathologic features of RGC according to previous reconstruction method and factors affecting the interval from previous curative distal gastrectomy for gastric cancer to RGC occurrence.

METHODS

Medical records of patients diagnosed with RGC at Yeungnam University Medical Center from January 2000 to December 2017 who had a history of distal gastrectomy with D2 LN dissection due to gastric cancer were reviewed retrospectively.

RESULTS

Forty-eight patients were enrolled in this study. The mean interval of 48 RGC patients was 105.6 months (8.8 years). RGC after Billroth II reconstruction recurred more often at anastomosis site than RGC after Billroth I reconstruction (p = 0.001). The mean interval of RGC after Billroth I reconstruction was 67 months, shorter than 119 months of RGC after Billroth II reconstruction (p = 0.003). On the contrary, interval showed no difference according to stage of previous gastric cancer, remnant gastric cancer, or sex (p = 0.810, 0.145, and 0.372, respectively).

CONCLUSIONS

RGC after Billroth I reconstruction tends to arise earlier at non-anastomosis site than RGC after Billroth II. Therefore, we should examine non-anastomosis site carefully from the beginning of surveillance after gastric cancer surgery with Billroth I reconstruction for better outcome.

DNA methylation genome-wide analysis in remnant and primary gastric cancers

BACKGROUND

Although primary (PGC) and remnant gastric cancers (RGC) both originate from the same gastrointestinal organ, they have very distinct clinicopathological behaviors. We hypothesized that there would be distinct differences in DNA methylation patterns that would occur during carcinogenesis of RGC and PGC, and that the differences in methylation patterns may help identify the primary factor contributing to chronic inflammation in patients with RGC.

METHODS

We investigated the genome-wide DNA methylation patterns of PGC and RGC tissues from 48 patients using the Infinium HumanMethylation450 Beadchip assay. The results were validated by quantitative methylation-specific PCR (qMSP) in separate, independent cohorts.

RESULTS

We found that in our training cohort of 48 patients, the most variable genes from the gastric cancer tissues identified by the Infinium HumanMethylation450 Beadchip clustered the resultant heatmap into high and low methylation groups. On multivariate analysis, PGCs contributed significantly to the high methylation group (p = 0.004, OR 12.33), which suggested that the promoter methylation status in PGC is higher than that in RGC. Supporting this conclusion was the finding that in a separate qMSP analysis in a test cohort, the EPB41L3 gene, chosen because of its high β value on microarray analysis in the gastric cancer tissues, had significantly higher DNA promoter methylation in cancer tissues in the validation PGC tissues than in RGC.

CONCLUSIONS

This study demonstrated that promoter methylation status in PGC is higher than in RGC. This result may reflect the effects of the absence of Helicobacter pylori on the reduced DNA methylation in the remnant stomach.

Surgical resection of gastric stump cancer following proximal gastrectomy for adenocarcinoma of the esophagogastric junction

BACKGROUND

Proximal gastrectomy (PG) is performed widely as a function-preserving operation for early gastric cancer located in the upper third of the stomach and is an important function-preserving approach for esophagogastric junction (EGJ) adenocarcinoma. The incidence of gastric stump cancer (GSC) after PG is increasing. However, little is known about the GSC following PG because very few studies have been conducted on the disease.

AIM

To clarify clinicopathologic features, perioperative complications, and long-term survival rates after the resection of GSC following PG.

METHODS

Data for patients with GSC following PG for adenocarcinoma of the EGJ diagnosed between January 1998 and December 2016 were retrospectively reviewed. Multivariate analysis was performed to identify factors associated with overall survival (OS). GSC was defined in accordance with the Japanese Gastric Cancer Association.

RESULTS

A total of 35 patients were identified. The median interval between the initial PG and resection of GSC was 4.9 (range 0.7-12) years. In 21 of the 35 patients, the tumor was located in a nonanastomotic site of the gastric stump. Total gastrectomy was performed in 27 patients; the other 8 underwent partial gastrectomy. Postoperative complications occurred in 6 patients (17.1%). The tumor stage according to the depth of tumor invasion was T1 in 6 patients, T2 in 3 patients, T3 in 9 patients, and T4 in 17 patients. Lymph node metastasis was observed in 18 patients. Calculated 1-, 3-, and 5-year OS rates were 86.5%, 62.3%, and 54.2%, respectively. Multivariate analysis showed advanced T stage to be associated with OS.

CONCLUSION

This study reveals the characteristics of GSC following PG for adenocarcinoma of the EGJ and suggests that a surgical approach can lead to a satisfactory outcome.

Clinical outcomes of endoscopic treatment for gastric epithelial neoplasm in remnant stomach after distal gastrectomy

BACKGROUNDS/AIM

We aimed to evaluate the feasibility of endoscopic treatment for gastric epithelial neoplasm in the remnant stomach after distal gastrectomy and compared the clinical outcomes by tumor location and endoscopic treatment modality.

METHODS

We reviewed the data of patients who underwent endoscopic treatment for gastric epithelial neoplasms in the remnant stomach after distal gastrectomy between January 1996 and August 2013. The treatments included endoscopic resection or argon plasma coagulation.

RESULTS

Herein, 107 patients (median age, 65.1 years; 92 men) encompassing 117 cases of gastric neoplasms in the remnant stomach after distal gastrectomy were endoscopically treated. Forty of these lesions were located at anastomotic sites; they were treated with endoscopic resection in 29 cases (72.5%) and argon plasma coagulation in 11 cases (27.5%). For 77 lesions located on the non-anastomotic site, endoscopic resection was performed in 68 cases (88.4%) and argon plasma coagulation was performed in nine cases (11.7%; p = 0.031). The mean endoscopic resection duration was significantly longer in the anastomotic site group than in the non-anastomotic site group (43.6 vs. 26.3 min, p = 0.018). Recurrence was observed in five (12.8%) patients in the former and in one (1.3%) in the latter (p = 0.015); all the patients were successfully retreated with endoscopic resection or APC.

CONCLUSIONS

Endoscopic treatment for gastric epithelial neoplasm in a remnant stomach after distal gastrectomy is effective and safe. However, closely monitoring for recurrence should be conducted, particularly when the tumor is located at the anastomotic site.

Development and External Validation of Web-Based Models to Predict the Prognosis of Remnant Gastric Cancer after Surgery: A Multicenter Study

BACKGROUND

Remnant gastric cancer (RGC) is a rare malignant tumor with poor prognosis. There is no universally accepted prognostic model for RGC.

METHODS

We analyzed data for 253 RGC patients who underwent radical gastrectomy from 6 centers. The prognosis prediction performances of the AJCC7th and AJCC8th TNM staging systems and the TRM staging system for RGC patients were evaluated. Web-based prediction models based on independent prognostic factors were developed to predict the survival of the RGC patients. External validation was performed using a cohort of 49 Chinese patients.

RESULTS

The predictive abilities of the AJCC8th and TRM staging systems were no better than those of the AJCC7th staging system (c-index: AJCC7th vs. AJCC8th vs. TRM, 0.743 vs. 0.732 vs. 0.744; P>0.05). Within each staging system, the survival of the two adjacent stages was not well discriminated (P>0.05). Multivariate analysis showed that age, tumor size, T stage, and N stage were independent prognostic factors. Based on the above variables, we developed 3 web-based prediction models, which were superior to the AJCC7th staging system in their discriminatory ability (c-index), predictive homogeneity (likelihood ratio chi-square), predictive accuracy (AIC, BIC), and model stability (time-dependent ROC curves). External validation showed predictable accuracies of 0.780, 0.822, and 0.700, respectively, in predicting overall survival, disease-specific survival, and disease-free survival.

CONCLUSIONS

The AJCC TNM staging system and the TRM staging system did not enable good distinction among the RGC patients. We have developed and validated visual web-based prediction models that are superior to these staging systems.

Is there difference between anastomotic site and remnant stump carcinoma in gastric stump cancers?-a single institute analysis of 90 patients

Background

Little has been reported regarding differences between malignancies that develop at the anastomotic site (ASC) and those that develop at the remnant stump (RSC) in gastric stump carcinomas (GSC). The purpose of our study was to compare clinical, pathological and survival characteristics of ASC patients with those of RSC patients.

Methods

Patients who underwent surgery for GSC between January 2005 and December 2017 were analyzed. Of the total 112 patients, 22 patients were excluded from the study due to extensive loss of data. Ninety patients underwent curative resection and were evaluated based on anatomic site at which they developed malignancy, i.e., ASC and RSC. Clinical, pathological and survival characteristics were assessed.

Results

As per Lauren's classification, diffuse and intestinal variety were significantly associated with ASC (P=0.0001) and RSC (P=0.0001) respectively. RSC was associated with lower pT [pT2, 15/33 (45.5%), P=0.0002]. ASC was significantly associated with higher pN [pN3, 30/57 (52.6%), P=0.0013], stage [stage III, 48/57 (84.2%), P=0.0022], positive mesenteric nodes (P=0.006) and poor 3-year survival (10.5% versus 36.4%, P=0.003).

Conclusions

ASC is substantially different than RSC. ASC is more aggressive disease compared to RSC and has different pathophysiology, higher rates of nodal involvement (both primary and mesenteric), presents with higher stage and has significantly poor 3-year survival.

Clinicopathological Features of Remnant Gastric Cancer (RGC): Detection of RGC after Five Years of Follow-Up Was Associated with a Poor Prognosis

The purpose of this study was to evaluate the clinicopathological features and prognosis of patients who underwent surgery for remnant gastric cancer (RGC) during/after the regular five-year follow-up period after initial distal gastrectomy for gastric cancer that is recommended by the Japanese gastric cancer treatment guidelines. Between January 2007 and December 2017, 40 patients underwent surgery for RGC after distal gastrectomy. Twenty-eight of the 40 patients underwent initial gastrectomy for cancer. We divided the 28 patients into two groups: patients who were diagnosed with RGC during/after the five-year follow-up period after initial gastrectomy, and analyzed their retrospectively collected data. Among the 28 patients, 15 patients were diagnosed with RGC within five years and 13 patients were diagnosed with RGC after five years. There were significant differences in the reconstruction of the initial operation, curative resection, pathological depth of the tumor, and pathological stage of the two groups. Multivariate analyses revealed that the interval between initial gastrectomy and RGC and the pathological TNM stage were significant risk factors for shorter cancer-specific survival. Kaplan-Meier analyses demonstrated that patients with RGC after the five-year follow-up period had a significantly worse prognosis in terms of cancer-specific survival than those who developed RGC within five years. This study suggested surveillance by using the annual endoscopy might be necessary beyond the initial five-year period for patients who underwent gastrectomy for gastric cancer.

Carcinoma in the Remnant Stomach During Long-Term Follow-up After Distal Gastrectomy for Gastric Cancer: Analysis of Cumulative Incidence and Associated Risk Factors

BACKGROUND

The number of patients with remnant gastric cancer following resection of gastric cancer may increase. The aims of this study were to investigate the development of remnant gastric cancer after distal gastrectomy for gastric cancer and to examine its cumulative incidence, clinicopathological characteristics, and risk factors.

METHODS

We examined 437 patients with relapse-free survival for 5 years or more after distal gastrectomy with Billroth I reconstruction for gastric cancer performed between 1985 and 2005.

RESULTS

A total of 17 patients suffered from remnant gastric cancer. The cumulative incidence was 3.7% at 10 years and 5.4% at 20 years. The median time until development of remnant gastric cancer was 79 months (range 30-209 months). The presence of synchronous multiple gastric cancers was a significant independent risk factor for remnant gastric cancer (hazard ratio 4.036; 95% confidence interval 1.478-11.02; P = 0.006). Of the 17 patients, the 13 whose remnant gastric cancer was detected via regular endoscopy showed better prognoses than the patients detected by other means (P < 0.001).

CONCLUSION

The cumulative incidence of remnant gastric cancer was 5.4% at 20 years. In particular, patients who had multiple gastric cancers at initial gastrectomy were at higher risk for remnant gastric cancer. Therefore, long-term endoscopic surveillance is important.