Clinicopathological characteristics and survival difference between gastric stump carcinoma and primary upper third 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.

Predictive value of positive lymph node ratio in patients with locally advanced gastric remnant cancer

BACKGROUND

Traditional lymph node stage (N stage) has limitations in advanced gastric remnant cancer (GRC) patients; therefore, establishing a new predictive stage is necessary.

AIM

To explore the predictive value of positive lymph node ratio (LNR) according to clinicopathological characteristics and prognosis of locally advanced GRC.

METHODS

Seventy-four patients who underwent radical gastrectomy and lymphadenectomy for locally advanced GRC were retrospectively reviewed. The relationship between LNR and clinicopathological characteristics was analyzed. The survival analysis was performed using Kaplan-Meier survival curves and Cox regression model.

RESULTS

Number of metastatic LNs, tumor diameter, depth of tumor invasion, Borrmann type, serum tumor biomarkers, and tumor-node-metastasis (TNM) stage were correlated with LNR stage and N stage. Univariate analysis revealed that the factors affecting survival included tumor diameter, anemia, serum tumor biomarkers, vascular or neural invasion, combined resection, LNR stage, N stage, and TNM stage (all P < 0.05). The median survival time for those with LNR0, LNR1, LNR2 and LNR3 stage were 61, 31, 23 and 17 mo, respectively, and the differences were significant (P = 0.000). Anemia, tumor biomarkers and LNR stage were independent prognostic factors for survival in multivariable analysis (all P < 0.05).

CONCLUSION

The new LNR stage is uniquely based on number of metastatic LNs, with significant prognostic value for locally advanced GRC, and could better differentiate overall survival, compared with N stage.

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.

Characteristics of alpha-fetoprotein-positive gastric cancer revealed by analysis of cancer databases and transcriptome sequencing data

Gastric cancer is one of the most common malignant tumors in the world. Alpha fetoprotein (AFP)-positive gastric cancer (AFPP-GC) is considered a special entity among gastric cancers. There is still controversy regarding the clinicopathological characteristics and prognosis of AFPP-GC, and the potential mechanism underlying its high malignant potential is still unclear. A comprehensive description of AFPP-GC genomic characteristics and regulatory mechanisms is lacking. This study analyzed the pathological characteristics and prognosis of AFPP-GC by utilizing clinical samples. The results showed that AFPP-GC has a poor prognosis and a high of risk liver metastasis. Tissue transcriptome sequencing showed that genes with high expression in AFPP-GC were involved in the activation of various cancer pathways, and genes with low expression were involved in the immune response. Single-sample gene set enrichment analysis showed that overexpression of AFP in AFPP-GC significantly inhibited the infiltration of CD8+ T cells. To further explore the genomic characteristics of AFPP-GC, the signaling pathway by which AFP regulates the invasion and metastasis of AFPP-GC cells was discussed. The results showed that AFPP-GC may promote cell invasion by regulating the PTEN/AKT1/SOX5/CES1 signaling axis. This study reveals the molecular mechanism underlying the increased malignant potential of AFPP-GC vs. AFP-negative gastric cancer (AFPN-GC). This provides important information for individualized treatment of AFPP-GC.

Clinicopathological Predisposing Factors for Gastric Stump Cancer and Its Management: A Single-Center Analytical Study

Background The incidence of gastric stump carcinoma (GSC) is not declining because of the long latency period. The survival rate of treated gastric cancer patients has increased due to early detection and improvements in surgical techniques and chemotherapy. Increased survival rates and improved surveillance following gastric surgery have increased the incidence of GSC. Aim The study aims to investigate the clinicopathological factors affecting the interval between index gastric surgery and the occurrence of GSC, and our experience in the management of GSC is presented. Methods A retrospective review of patients diagnosed with GSC in our institution was completed. Patient characteristics and clinicopathological outcomes were analyzed. Results A total of 28 patients were included in this cohort with 17 (60.71%) males and 11 (39.28%) females. The mean interval from index surgery to the incidence of GSC was 24.42 years for benign etiology and six years for malignant etiology. Index surgeries were truncal vagotomy with 14 gastrojejunostomies (50%) and 14 subtotal gastrectomies (50%). The interval between index surgery and the incidence of GSC is not statistically significant concerning the type of surgery (p: 0.661), pathological TNM (tumor, nodes, metastases) stage (p: 0.520), pathological differentiation (p: 0.828), lymphovascular invasion (p: 0.252), perineural invasion (p: 0.672), and adjuvant therapy (p: -0.655). Survival was significantly higher in those patients who received curative resection in comparison to a palliative procedure (p: 0.041). Conclusion Strict surveillance for at least 10 years after initial gastric surgery is of utmost importance as half of the patients fated to develop GSC will do so within this time. In those patients with early diagnosis, no evidence of metastasis, and good performance status, curative surgery is feasible with acceptable morbidity.

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.

Involvement in the tumor-infiltrating CD8+ T cell expression by the initial disease of remnant gastric cancer

BACKGROUND

Remnant gastric cancer (RGC) has been increasing for various reasons such as a longer life span, medical progress, and others. It generally has a poor prognosis, and its mechanism of occurrence is unknown. The purpose of this study was to evaluate the clinicopathological features of and clarify the oncological features of RGC.

METHODS

Between January 2002 and January 2017, 39 patients with RGC following distal gastrectomy underwent curative surgical resection at the Okayama University Hospital; their medical records and immunohistochemically stained extracted specimens were used for retrospective analysis.

RESULTS

On univariate analysis, initial gastric disease, pathological lymph node metastasis, and pathological stage were the significant factors associated with poor overall survival (p=0.014, 0.0061, and 0.016, respectively). Multivariate analysis of these 3 factors showed that only initial gastric disease caused by malignant disease was an independent factor associated with a poor prognosis (p=0.014, hazard ratio: 4.2, 95% confidence interval: 1.3-13.0). In addition, tumor-infiltrating CD8⁺ T cells expression was higher in the benign disease group than in the malignant group (p=0.046).

CONCLUSIONS

Initial gastrectomy caused by malignant disease was an independent poor prognostic factor of RGC, and as one of the causes, lower level of tumor-infiltrating CD8⁺ T cells in RGC may involve in.

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.

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.

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.

Laparoscopic Completion Total Gastrectomy as a Standardized Procedure for Gastric Stump Cancer: A Case Control Study

Objective

Complete gastrectomy for gastric stump cancer (GSC) can be challenging due to severe adhesions; therefore, advanced techniques are required when being performed by laparoscopic surgery. This study aimed to evaluate the clinical outcomes of laparoscopic completion total gastrectomy (LCTG) for the treatment of GSC.

Methods

Patient records from January 2010 to October 2018 were retrospectively evaluated. The patients were classified into 2 groups depending on whether they underwent open or laparoscopic gastrectomy. We compared patient characteristics; operative, clinical, and pathological data between the groups.

Results

Twenty open and 17 LCTGs were performed. Laparoscopic gastrectomy resulted in a significantly longer operation time (230 versus 182.5 min; P = 0.026), lower blood loss (14 versus 105 mL; P &lt; 0.001), and shorter period to the first flatus passage (2 versus 3 days; P &lt; 0.001) than open gastrectomy. No significant differences in the number of retrieved lymph nodes, duration of hospital stay, complication rate, and postoperative analgesic usage between the 2 groups were observed. No patients required conversion to open surgery in the laparoscopic-treatment group. Pathologic findings revealed that the laparoscopic group had a smaller tumor size (not pathologic T category) and fewer metastatic lymph nodes than the open group, leading to an earlier distribution of the pathologic stage in the laparoscopic group.

Conclusions

LCTG for the treatment of GSC was safely conducted with fewer complications and mortalities than previously reported results. Advanced technologies and sophistication of laparoscopic skills may further yield minimal invasiveness with better short-term outcome.

Impact of postoperative complications on survival outcomes in patients with gastric cancer: exploratory analysis of a randomized controlled JCOG1001 trial

BACKGROUND

Recent studies have found a negative impact of postoperative complications on long-term survival outcomes, but it has not been confirmed by data obtained from a prospective study with a large sample size. This study investigated the impact of postoperative complications on long-term survival outcomes, and considered the optimal definition of complication, using data from JCOG1001, which compared bursectomy and non-bursectomy for patients with cT3/4a locally advanced gastric cancer.

METHODS

This study included 1191 of 1204 patients enrolled in the JCOG1001 trial. Complications were graded by Clavien-Dindo (C-D) classification. Impact of the grade (≥ C-D grade II or ≥ grade III) or type (any or intra-abdominal infectious) of complication on survival outcome was evaluated by univariate and multivariable analyses using the Cox proportional hazard model.

RESULTS

The incidence of any ≥ C-D grade II and ≥ grade III complication was 23.0% and 9.7%, respectively, and that of ≥ grade II and ≥ grade III intra-abdominal infectious complication was 13.4% and 6.9%, respectively. Multivariable analysis showed all four definitions of complications were independent prognostic factors for overall survival. Conversely, only  any ≥ C-D grade III complication was found to be an independent prognostic factor for relapse-free survival (hazard ratio, 1.445; 95% confidence interval, 1.026-2.036; P = 0.035).

CONCLUSIONS

Postoperative complications adversely affect the long-term survival outcomes of patients with cT3/4a gastric cancer. Any ≥ C-D grade III complication seems to be the most suitable definition of complication for predicting negative long-term survival outcomes.

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.

Prevalence and characteristics of gastric remnant cancer: A systematic review and meta-analysis

The incidence and outcomes of GRC remain variable. Minority published researches have paid attention to the characteristics of GRC. This study aimed to make a systematic review and meta-analysis of the prevalence of GRC, with a focus on characteristics and survival rates of GRC. PubMed, EMBASE, and CENTRAL were searched for related clinical studies. Data were pooled using Stata 11.0, and subgroup and sensitivity analyses were performed if necessary and feasible. Moreover, SPSS (version 19.0) was used for comparing the clinical characteristics of GRC. Twenty studies were selected in this meta-analysis. The results indicated that the pooled prevalence of GRC was 2.6% (95% confidence interval (CI), 2.2-3.0%, p = 0.000). European population and American populations have a higher rate of prevalence of GRC than Chinese populations and Japan. There is no significant difference in histology and the TNM stage between the benign group and the malignant group. The five-year survival rate for GRC cases with benign primary gastric diseases is poorer than the primary gastric diseases malignant. Gastric remnant cancer is not a very rare clinical problem, especially for European and American patients. Active treatment and regular follow-up are conductive to increase 5-years survival rate.

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.

Perioperative chemotherapy for locally advanced gastric cancer in Japan: current and future perspectives

The standard treatment for locally advanced gastric cancer differs across the world. In western countries, perioperative chemotherapy or postoperative adjuvant chemoradiotherapy are the preferred treatment options, whereas in Asia, D2 gastrectomy followed by postoperative adjuvant chemotherapy is standard. In Japan, adjuvant chemotherapy with S-1 is the standard treatment for pStage II gastric cancer, whereas adjuvant chemotherapy with a doublet regimen is preferred for pStage III gastric cancer. The efficacy of preoperative neoadjuvant chemotherapy using S-1 plus cisplatin, has been investigated in selected patients with expected poor survival outcomes. To expand the indications for neoadjuvant chemotherapy, a clinical trial investigating the efficacy of preoperative S-1 plus oxaliplatin in patients with cStage III (cT3-4N1-3) gastric cancer (JCOG1509) is ongoing in Japan. The addition of immune checkpoint inhibitors to cytotoxic chemotherapy also seems promising and is being investigated in international randomized clinical trials. Although we have to await the final results of these studies, preoperative neoadjuvant chemotherapy is a promising treatment strategy and likely to become standard treatment for locally advanced gastric cancer in Japan.

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.

Effects of initial disease status on lymph flow following gastrectomy in cases of carcinoma in the remnant stomach

PURPOSE

In cases of carcinoma in the remnant stomach (CRS), the lymphatic flow may be altered by the initial surgery. In this study of CRS after gastrectomy, we investigated how the regions of lymph node metastasis and changes in lymphatic flow depend on initial disease status.

METHOD

The study included 76 patients with CRS who underwent gastrectomy between September 2002 and November 2014. We analyzed and compared the clinicopathological factors and survival periods between patients after distal gastrectomy for malignant disease (group M, 33 patients) and patients after distal gastrectomy for benign disease (group B, 43 patients).

RESULTS

The depth of tumor invasion was more advanced in group B (T1/T2/T3/T4: group M 18/1/7/7, group B 8/11/8/16; P = 0.002). However, the degree of lymph node metastasis did not differ significantly between the two groups. The incidence of lymph node metastasis was high at stations 2 (19 %), 4sa (17 %), 10 (25 %), 11p (19 %), and 11d (27 %) in group M and 1 (14 %), 3 (23 %), and 4sb (15 %), and the mesojejunal lymph node (21 %) in group B. Lymph node dissection was highly beneficial at station 3, station 7, and the mesojejunum in both groups, but not at stations 10 or 11d.

CONCLUSION

As compared with group B, group M showed higher incidences of lymph node metastasis in the greater curvature, splenic hilum, and lymph nodes along the splenic artery, suggesting the predominance of lymphatic flows from the greater curvature to the splenic hilum and from the remnant stomach to the splenic artery.

Staging for Remnant Gastric Cancer: The Metastatic Lymph Node Ratio vs. the UICC 7th Edition System

BACKGROUND

Unlike primary gastric cancer, a remnant gastric cancer (RGC) staging system has not been established. The retrieved lymph node counts (RLN) in RGC is generally lower than that in primary gastric cancer, so it is unclear whether positive lymph node count reflects the RGC patient's survival. Therefore, the lymph node ratio (LR) may be more useful for RGC staging than the 7th edition UICC classification.

METHODS

Patients (n = 191) who underwent gastrectomy with curative intent for RGC participated in this study. LR was classified as LR = 0, 0 < LR ≤ 0.1, 0.1 < LR ≤ 0.4, and 0.4 < LR. Modified TNM staging (mTNM-LR) was established by combining the pT (7th UICC) with LR. The predictive accuracy of LR and mTNM-LR was compared with that of the pN (7th UICC) and TNM (7th UICC), respectively.

RESULTS

The mean RLN was 14.4 and that of 128 patients (67 %) was ≤15. Fifty-one patients (27 %) had metastatic lymph nodes. Multivariable analyses revealed that pT (7th UICC) (p < 0.001) and pN (7th UICC) (p = 0.001), but not LR, were independent risk factors for overall survival. The overall c-index (95 % confidence interval) of each staging system was as follows: pN (7th UICC): 0.700 (0.627-0.771); LR: 0.701 (0.627-0.775), TNM (7th UICC): 0.808 (0.761-0.870); mTNM-LR: 0.807 (0.737-0.871). There were no significant differences in the predictive accuracy between pN (7th UICC) and LR, and TNM (7th UICC) and mTNM-LR.

CONCLUSIONS

LR was not superior to pN (7th UICC). Thus, the 7th edition UICC classification is a practical and reliable staging system for RGC.

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

Remnant gastric cancer, most frequently defined as cancer detected in the remnant stomach after distal gastrectomy for benign disease and those cases after surgery of gastric cancer at least 5 years after the primary surgery, is often reported as a tumor with poor prognosis. The Task Force of Japanese Gastric Cancer Association for Research Promotion evaluated the clinical impact of remnant gastric cancer by systematically reviewing publications focusing on molecular carcinogenesis, lymph node status, patient survival, and surgical complications. A systematic literature search was performed using PubMed/MEDLINE with the keywords "remnant," "stomach," and "cancer," revealing 1154 relevant reports published up to the end of December 2014. The mean interval between the initial surgery and the diagnosis of remnant gastric cancer ranged from 10 to 30 years. The incidence of lymph node metastases at the splenic hilum for remnant gastric cancer is not significantly higher than that for primary proximal gastric cancer. Lymph node involvement in the jejunal mesentery is a phenomenon peculiar to remnant gastric cancer after Billroth II reconstruction. Prognosis and postoperative morbidity and mortality rates seem to be comparable to those for primary proximal gastric cancer. The crude 5-year mortality for remnant gastric cancer was 1.08 times higher than that for primary proximal gastric cancer, but this difference was not statistically significant. In conclusion, although no prospective cohort study has yet evaluated the clinical significance of remnant gastric cancer, our literature review suggests that remnant gastric cancer does not adversely affect patient prognosis and postoperative course.

Current status in remnant gastric cancer after distal gastrectomy

Remnant gastric cancer (RGC) and gastric stump cancer after distal gastrectomy (DG) are recognized as the same clinical entity. In this review, the current knowledges as well as the non-settled issues of RGC are presented. Duodenogastric reflux and denervation of the gastric mucosa are considered as the two main factors responsible for the development of RGC after benign disease. On the other hand, some precancerous circumstances which already have existed at the time of initial surgery, such as atrophic gastritis and intestinal metaplasia, are the main factors associated with RGC after gastric cancer. Although eradication of Helicobacter pylori (H. pylori) in remnant stomach is promising, it is still uncertain whether it can reduce the risk of carcinogenesis. Periodic endoscopic surveillance after DG was reported useful in detecting RGC at an early stage, which offers a chance to undergo minimally invasive endoscopic treatment or laparoscopic surgery and leads to an improved prognosis in RGC patients. Future challenges may be expected to elucidate the benefit of eradication of H. pylori in the remnant stomach if it could reduce the risk for RGC, to build an optimal endoscopic surveillance strategy after DG by stratifying the risk for development of RGC, and to develop a specific staging system for RGC for the standardization of the treatment by prospecting the prognosis.

Characteristics of gastric stump cancer: A single hospital retrospective analysis of 262 patients

BACKGROUND

Owing to its relative rarity, the characteristics of gastric stump cancer (GSC) have not been fully understood. In this study, we clarified the detailed characteristics from a large cohort of GSC patients.

PATIENTS AND METHODS

For this retrospective cohort study from 1 hospital in Japan, we recruited 262 GSC patients who underwent surgery for GSC between 1984 and 2012. GSC was defined in accordance with Japanese Gastric Cancer Association. Stage was categorized in accordance with the 7th TNM classification for primary gastric cancer.

RESULTS

Although the time interval between the primary and second operations differed significantly depending on the primary disease (34.3 years for benign vs 9.9 years for malignant on average), it did not influence survival. The 5-year overall survival rates of patients with N0, N1, N2, and N3 were 70.4%, 27.7%, 21.8%, and 6.4%, respectively, whereas the rates for those with stage I, II, III, and IV were 77.8%, 37.4%, 18.6%, and 10.5%, respectively. Recurrence in the peritoneum was the most common pattern, followed by recurrence in the local region or lymph nodes. The Cox proportional hazard model demonstrated that age > 65, T stage, N stage, and tumor histology were significant independent prognostic factors for survival, whereas neither primary disease nor primary anastomosis type significantly impacted survival.

CONCLUSION

Neither primary disease nor anastomosis type affected survival significantly, despite significant differences in their characteristics. In addition, the time interval between the primary and second surgery did not impact survival.

Surgical Resection of Remnant Gastric Cancer Following Distal Gastrectomy: A Retrospective Clinicopathological Study

BACKGROUND

Remnant gastric cancer (RGC) is one of the less prevalent gastric cancers. The purpose of this study was to explore the clinicopathological characteristics and results of the operation of RGC following distal gastrectomy. In particular, we examined factors related to prognosis.

METHODS

Between January 1970 and December 2012, 122 patients with RGC following distal gastrectomy underwent further surgery and were analyzed retrospectively.

RESULTS

Initial gastric diseases included benign (49 patients, 40.2 %) and malignant diseases (73 patients, 59.8 %). Reconstructions by initial surgery included Billroth I (80 patients, 65.6 %) and Billroth II (42 patients, 34.4 %). Tumors were located at anastomotic (44 patients, 36.1 %) and nonanastomotic sites (78 patients, 63.9 %). There were 59 patients (48.4 %) classified with pathological (p) stage I, 19 as p stage II (15.6 %), 22 as p stage III (18.0 %), and 22 (18.0 %) as p stage IV. A total of 100 patients (82.0 %) underwent curative resection, and 22 underwent noncurative resection. The number of cases of postoperative morbidity, 90-day mortality, and adjuvant chemotherapy were 23 (18.9 %), 3 (2.5 %), and 20 (16.4 %), respectively. Univariate and multivariate analyses were performed to identify the prognostic factors of RGC. Multivariate analysis revealed historical periods, pathological venous invasion, curative resection, and postoperative morbidity to be independent prognostic factors.

CONCLUSIONS

The prognosis of patients with RGC can be improved by aggressively performing curative resection without causing complications.

Effect of the number of lymph nodes harvested on the long-term survival of gastric cancer patients according to tumor stage and location: a 12-year study of 1,637 cases

BACKGROUND

The effect of the number of lymph nodes harvested on the long-term survival of gastric cancer according to Tumor, Node, and Metastasis (TNM) stage and tumor location remains unclear.

METHODS

Patients who underwent gastrectomy for gastric cancer (1998 to 2009) were evaluated retrospectively (1,637 patients). The patients' clinicopathological variables, overall survival (OS), and progression-free survival (PFS) were recorded. The effect of the number of lymph nodes harvested on survival was analyzed according to TNM stage and tumor location.

RESULTS

Harvest of greater than 30 lymph nodes was associated with significantly better OS and PFS than less than or equal to 14 lymph nodes, but no significant difference was observed between less than or equal to 14 and 15 to 29 lymph nodes harvested. The number of lymph nodes harvested was significantly associated with the OS or/and PFS of late stage cancer (N+, T3 to T4, and stage III to IV), harvest of greater than 30 lymph nodes brought significantly better survival compared with the other 2 groups. A higher number of harvested lymph nodes was associated with significantly better PFS for gastric cancer of the body of stomach, but not for proximal, distal, and whole stomach cancer. When the tumor was located in the body of the stomach, the PFS was better with 15 to 29 lymph nodes than less than 14 lymph nodes; however, the OS and PFS were not significantly different between greater than 30 lymph nodes and 15 to 29 lymph nodes. TNM stage and number of lymph nodes harvested were the independent risk factors affecting the survival.

CONCLUSION

Tailored lymphadenectomy according to TNM stage and tumor location might be considered for gastric cancer patients.

Significant differences in the clinicopathological characteristics and survival of gastric cancer patients from two cancer centers in china and Korea

PURPOSE

To compare the clinicopathological data and long-term survival of gastric cancer patients in China and Korea.

MATERIALS AND METHODS

Patients who had undergone gastrectomy for gastric cancer between 1998 and 2009 in 2 high-volume institutions in both China (n=1,637) and Korea (n=2,231) were retrospectively evaluated. Clinicopathological variables, overall survival (OS), progression-free survival (PFS), and surgery-related complications were assessed for all patients and compared between the 2 institutions.

RESULTS

Chinese patients included in the study were significantly older and had a significantly lower body mass index (BMI) than the Korean patients. Esophagogastric junction tumors were more frequent in Chinese patients. However, the number of patients with stage I gastric cancer, the number of harvested lymph nodes, and the number of total gastrectomies were significantly higher in the Korean population. Korean patients also presented with fewer undifferentiated tumors than Chinese patients. Furthermore, Korean patients had prolonged OS and PFS for stage III cancers only. BMI, tumor-node-metastasis (TNM) stage, tumor invasion, number of positive lymph nodes, and distant metastases were all independent factors affecting OS and PFS.

CONCLUSIONS

Although China and Korea are neighboring Asian countries, the clinicopathological characteristics of Chinese patients are significantly different from those of Korean patients. Korean gastric cancer patients had longer OS and PFS than Chinese patients. Influencing factors included TNM stage, tumor invasion, and lymph node metastasis.

Prognostic factors and survival in patients with gastric stump cancer

AIM: To elucidate the clinicopathological characteristics and prognostic factors of gastric stump cancer (GSC).

METHODS: The clinical data for 92 patients with GSC were collected at Fudan University Shanghai Cancer Center. The prognostic factors were analyzed with Cox proportional hazard models.

RESULTS: GSC tended to occur within 25 years following the primary surgery, when the initial disease is benign, whereas it primarily occurred within the first 15 years post-operation for gastric cancer. Patients with regular follow-up after primary surgery had a better survival rate. The multivariate Cox regression analysis revealed that Borrmann type I/II (HR = 3.165, 95%CI: 1.055-9.500, P = 0.040) and radical resection (HR = 1.780, 95%CI: 1.061-2.987, P = 0.029) were independent prognostic factors for GSC. The overall 1-, 3-, and 5-year survival rates of the 92 patients were 78.3%, 45.6% and 27.6%, respectively. The 1-, 3-, and 5-year survival rates of those undergoing radical resection were 79.3%, 52.2%, and 37.8%, respectively. The 5-year survival rates for stages I, II, III, and IV were 85.7%, 47.4%, 16.0%, and 13.3%, respectively (P = 0.005).

CONCLUSION: The appearance of GSC occurs sooner in patients with primary malignant cancer than in patients with a primary benign disease. Therefore, close follow-up is necessary. The overall survival of patients with GSC is poor, and curative resection can improve their prognosis.

Gastric stump cancer: more than just another proximal gastric cancer and demanding a more suitable TNM staging system

Background. Considerable controversy persists about the biological behavior of gastric stump cancer (GSC). The aim of this study is to clarify if this cancer is just another proximal gastric cancer or if it emerges as a distinctive clinicopathologic entity. Methods. This review of a prospectively collected gastric cancer database identified 73 patients with GSC in a single institution between January 1980 and June 2012 and compared them with 328 patients with proximal gastric cancer (PGC) and 291 patients with esophagogastric junction cancer (EGJC). Results. Patients with GSC were predominantly males. Eighty-three percent of GSC penetrated the subserosal or the serosal layers. The median number of lymph nodes retrieved in GSC patients was significantly lower than in PGC patients or in EGJC patients. Cumulative survival curves were not different between GSC, PGC, or EGJC patients. Unlike that observed in PGC and in EGJC, no significant differences in cumulative survival according to the TNM staging system were observed in GSC cases. Conclusions. The outcome of patients with GSC displayed significant differences when compared to those with other proximal gastric cancers concerning the lack of survival association with the TNM staging system. Therefore a more suitable staging system should be designed for these unique cancers.

A Caliber Persistent Artery (Dieulafoy's Lesion) which is Associated with an Early-Stage Gastric Stump Cancer Following a Distal Gastrectomy

A 75-years old man was hospitalized with symptoms which suggested gastric cancer. Thirty-eight years ago, he had undergone a Billroth-II gastric reconstruction for a peptic ulcer. At the present admission, he had presented with an eight-month history of recurrent haematemesis, epigastric pain, vomiting, and fatigue. The emergent endoscopy showed a type 0-IIc (superficial depressed) early gastric stump cancer in the anastomotic area and total removal of the gastric remnant and the jejunal segment was performed. The histological examination of the surgical specimen showed a gastric adenocarcinoma that invaded the mucosa and the submucosa, without lymph node metastases (pT1bN0 stage). Besides the tumour, enlarged vessels were observed in the submucosa and the muscularis propria, some of which were thrombotic. The surrounding normal gastric wall also presented submucosal oversized vascular spaces, some of which were protruding through the muscularis mucosae in the mucosal layer. Based on these characteristics and the recurrent haematemesis, a final diagnosis of early gastric stump carcinoma which was associated with Dieulafoy's lesion was made. This association has not yet been reported in the literature and it allowed us to diagnose the gastric stump cancer in a very early stage.