Remnant Gastric Cancer Research Articles

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

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. 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). 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 4.6years, disease recurrence occurred in 24.3% of patients. Most recurrences (over 80%) occurred within 2.5years, and 96.1% within 5years 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). 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.

Survival outcome and prognostic factors of remnant gastric cancer: a propensity score-matched analysis.

Studies on survival and prognostic factors in individuals with remnant gastric cancer (RGC) after gastric cancer (GC) are rare. It is debatable whether prognosis of RGC after GC is worse than that of only primary GC (OPGC). The objective of this study is to compare the survival outcomes between post-GC RGC and OPGC undergoing surgical resection and to identify the prognostic factors of disease-specific survival (DSS) for RGC. We retrospectively collected data from the Surveillance, Epidemiology, and End Results (SEER) database among patients who underwent GC surgery in 1988-2020. Propensity score matching (PSM) was conducted to balance baseline characteristics. Kaplan-Meier (KM) survival analysis was performed to compare their overall survival (OS) and DSS. Multivariable Cox analyses were performed to identify the independent prognostic factors of DSS for post-GC RGC by estimating hazard ratios (HRs) with 95% confidence intervals (CIs). There were 76 patients with RGC and 32,763 patients with OPGC included and analyzed. After balancing the baseline characteristics by PSM, no significant difference existed between OPGC and RGC groups in both OS (P=0.65) and DSS (P=0.28). Fixed-time analyses also showed no difference between the two groups for the 5-year (60.0%, RGC vs. 53.3%, OPGC, P=0.38) and 10-year DSS (56.7%, RGC vs. 48.3%, OPGC, P=0.34). Multivariable analysis revealed that area of lower income ($75,000+ vs. <$55,000, HR =0.21, 95% CI: 0.05-0.89, P=0.03), cardiac tumor [middle vs. cardia, HR =0.16, 95% CI: 0.03-0.77, P=0.02; distal vs. cardia, HR =0.10, 95% CI: 0.02-0.58, P=0.01; not otherwise specified (NOS) vs. cardia, HR =0.11, 95% CI: 0.03-0.51, P=0.004], deeper invasion (T3-4 vs. Tis-2, HR =5.19, 95% CI: 1.21-22.15, P=0.03), higher grade (G3 vs. G1-2, HR =7.35, 95% CI: 1.41-38.48, P=0.02) and not receiving chemotherapy (yes vs. no/unknown, HR =0.16, 95% CI: 0.04-0.60, P=0.007) were independent risk factors for postsurgical DSS in patients with post-GC RGC. The prognosis of post-GC RGC was comparable to that of OPGC following surgical resection. The independent prognostic factors for RGC are similar to those established for OPGC. Our findings suggest that RGC following first GC might be the same entity to OPGC and curative resection should be considered in selected patients.

Feasibility of Extended Postoperative Follow-Up in Patients With Gastric Cancer

Conventional research and guidelines on postgastrectomy follow-up for gastric cancer often restrict their focus to the first 5 years after surgery. To evaluate the association of extended regular follow-up after 5 years postgastrectomy in patients with gastric cancer with overall and postrecurrence survival rates. This population-based, retrospective cohort study used Korean National Health Insurance claims data extracted between January 1, 2005, and December 31, 2014, with follow-up data examined until December 31, 2021. Patients without recurrence or other cancers at 5 years postgastrectomy were divided into 2 groups: those who had extended regular follow-up visits and those who did not. The data were analyzed between August 15 and November 15, 2023. Regular follow-up vs irregular follow-up after 5 years postgastrectomy. The main outcome was whether extended regular follow-up after 5 years postgastrectomy was independently associated with overall and postrecurrence survival rates using Cox proportional hazards regression. Postrecurrence survival rates were also compared across different follow-up methods and intervals. A total of 40 468 patients with gastric cancer were included, with 14 294 in the regular follow-up group (mean [SD] age, 61.3 [11.7] years; 9669 male [67.8%]) and 26 174 in the irregular follow-up group (mean [SD] age, 58.1 [11.1] years; 18 007 male [68.8%]). Late recurrence or gastric remnant cancer (GRC) was identified in 3138 patients (7.8%), including 1610 of 40 468 patients (4.0%) between 5 and 10 years postgastrectomy and 1528 of 16 287 (9.4%) patients after 10 years postgastrectomy. Regular follow-up was associated with a significantly decreased overall mortality rate after 5 years postgastrectomy (from 49.4% to 36.9% in 15-year mortality rate; P < .001), as well as significant improvement of postrecurrence survival rate after occurrence of late recurrence or GRC (from 32.7% to 71.1% in 5-year postrecurrence survival rate; P < .001). Comparison of follow-up methods revealed that the combination of endoscopy and abdominopelvic computed tomography (CT) (only abdominopelvic CT in total gastrectomy subgroup) yielded the highest 5-year postrecurrence survival rate (endoscopy alone vs abdominopelvic CT alone vs a combination of both, 54.5% vs 47.1% vs 74.5%, respectively). A time interval of more than 2 years between previous endoscopy or abdominopelvic CT and late recurrence and GRC diagnosis was associated with a significantly reduced postrecurrence survival rate (hazard ratio, 1.72 [95% CI, 1.45-2.04] and 1.48 [95% CI, 1.25-1.75], respectively). These findings suggest that extended regular follow-up after 5 years postgastrectomy should be implemented clinically and that current practice and value of follow-up protocols in postoperative care of patients with gastric cancer be reconsidered.

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

e16119 Background: Traditional lymph node stage (N stage) has limitations in advanced gastric remnant cancer (GRC)patients; therefore, establishing a new predictive stage is necessary.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 &lt; 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 &lt; 0.05). Conclusions: 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.

466P A prospective study on the safety and feasibility of laparoscopic completion total gastrectomy for remnant gastric cancer

466P A prospective study on the safety and feasibility of laparoscopic completion total gastrectomy for remnant 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.

Conversion surgery for gastric remnant cancer with liver metastasis after nivolumab combination chemotherapy achieving pathological complete response: a case report and literature review.

Nivolumab combination chemotherapy has recently emerged as a potential first-line treatment for patients with unresectable or metastatic gastric cancer (GC). Further research has indicated that R0 resection by conversion surgery could be an effective treatment strategy to improve overall survival. However, there have been limited reports on the successful application of conversion surgery following combination chemotherapy achieving pathological complete response (pCR) in cases of advanced gastric remnant cancer with liver metastasis. Here, we present a case of long-term survival in a patient who underwent this treatment. A 54-year-old man was initially referred to our department for treatment of stage III (cT3N1M0) gastric cancer where he underwent laparoscopic distal gastrectomy and D2 lymph node dissection. After a year of uneventful follow-up, the patient was diagnosed with a tumor in the gastric remnant combined with liver metastasis, resulting in a diagnosis of stage IV (cT3N0M1) gastric remnant cancer. Subsequently, the patient was treated with four cycles of TS-1, Oxaliplatin, and Nivolumab as the first-line regimen. Remarkably, both the remnant tumor and liver metastasis exhibited significant shrinkage, and no new lesions were found. Given this response, conversion surgery was performed to achieve complete resection of the remnant gastric cancer and liver metastasis, followed by laparoscopic remnant gastrectomy and partial hepatectomy. Pathological examination revealed the absence of residual carcinoma cells and lymph node metastases. Postoperatively, the patient was treated with adjuvant chemotherapy with S-1 for 1 year, and survived without recurrence for 18months after conversion surgery. Nivolumab combination chemotherapy shows promise as a clinically beneficial treatment approach for gastric remnant cancer with liver metastasis, particularly when pCR can be achieved following conversion surgery.

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

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

Using the geriatric nutritional risk index to predict outcomes in older patients with remnant gastric cancer after gastrectomy: a retrospective multicenter study in Japan.

This study investigated the prognostic value of the geriatric nutritional risk index (GNRI) in patients undergoing curative gastrectomy for remnant gastric cancer (RGC). This multicenter retrospective study included 105 patients with RGC of ≥ 65 years of age who underwent curative gastrectomy at 10 institutions in Japan between January 2000 and December 2016. Postoperative complications, overall survival (OS), and disease-specific survival (DSS) were analyzed. Receiver operating curve analyses indicated that the optimal cutoff value of the GNRI for OS was 95.4. Patients were categorized into high and low GNRI groups based on the optimal GNRI cutoff value. The GNRI was significantly correlated with body mass index (p < 0.001), amount of bleeding (p = 0.021), Clavien-Dindo grade 5 postoperative complications (p = 0.040), death caused by primary disease (p = 0.010), and death caused by other diseases (p = 0.002). The OS and DSS were significantly worse in the low GNRI group. A low GNRI and T3 or deeper tumor invasion were independent prognostic factors for OS and DSS. The GNRI is a promising predictor of both short- and long-term outcomes in older patients with RGC.

The safety, feasibility and oncological outcomes of laparoscopic completion total gastrectomy for remnant gastric cancer: a prospective study with 3-year follow-up (FUGES-004 study).

The efficacy of laparoscopic completion total gastrectomy (LCTG) for remnant gastric cancer (RGC) remains controversial. The primary outcome was postoperative morbidity within 30 days after surgery. Secondary outcomes included 3-year disease-free survival (DFS), 3-year overall survival (OS), and recurrence. Inverse probability treatment weighted (IPTW) was used to balance the baseline between LCTG and OCTG. Final analysis included 46 patients with RGC who underwent LCTG at the FJMUUH between June 2016 and June 2020. The historical control group comprised of 160 patients who underwent open completion total gastrectomy (OCTG) in the six tertiary teaching hospitals from CRGC-01 study. After IPTW, no significant difference was observed between the LCTG and OCTG groups in terms of incidence (LCTG vs. OCTG: 28.0% vs. 35.0%, P=0.379) or severity of complications within 30 days after surgery. Compared with OCTG, LCTG resulted in better short-term outcomes and faster postoperative recovery. However, the textbook outcome rate was comparable between the two groups (45.9% vs. 32.8%, P=0.107). Additionally, the 3-year DFS and 3-year OS of LCTG were comparable to those of OCTG (DFS: log-rank P=0.173; OS: log-rank P=0.319). No significant differences in recurrence type, mean recurrence time, or 3-year cumulative hazard of recurrence were observed between the two groups (all P>0.05). Subgroup analyses and concurrent comparisons demonstrated similar trends. This prospective study suggested that LCTG was non-inferior to OCTG in both short- and long-term outcomes. In experienced centers, LCTG may be considered as a viable treatment option for RGC.

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

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

Safe and Accurate Laparoscopic Total Gastrectomy for Remnant Gastric Cancer With Severe Adhesions Using Indocyanine Green Fluorescence Imaging: Guidance in Detection of the Accurate Dissection Layer to Avoid Organ Injury.

Laparoscopic total gastrectomy (LTG) for remnant gastric cancer (RGC) requires advanced techniques due to severe postoperative adhesions and anatomic changes. We performed LTG in 2 patients with RGC using intraoperative indocyanine green (ICG) fluorescence imaging. Both cases previously underwent distal gastrectomy with Billroth-I reconstruction for gastric cancer and were subsequently diagnosed with early-stage gastric cancer of the remnant stomach. Indocyanine green (2.5mg/body) was administered intravenously during surgery. The liver and common bile duct were clearly visualized during surgery using near-infrared fluorescence laparoscopy, and the adhesions between the hepatobiliary organs and remnant stomach were safely dissected. Laparoscopic total gastrectomy was successfully performed without complications, and the postoperative course was uneventful in both cases. Intraoperative real-time ICG fluorescence imaging allows clear visualization of the liver and common bile duct and can be useful in LTG for RGC with severe adhesions.

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

Traditional lymph node stage (N stage) has limitations in advanced gastric remnant cancer (GRC) patients; therefore, establishing a new predictive stage is necessary. To explore the predictive value of positive lymph node ratio (LNR) according to clinicopathological characteristics and prognosis of locally advanced GRC. 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. 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). 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.

Clinical risk factors for splenic hilar nodal metastasis in remnant gastric cancer after distal gastrectomy.

270 Background: Splenectomy is usually considered to be required for complete dissection of splenic hilar lymph node (#10 LN) in gastric cancer (GC). Although spleen-preserving D2 was established for the advanced GC not invading the grater coverture based on the JCOG0110 clinical trial, D2 gastrectomy with splenectomy remains the standard procedure for the advanced GC involving grater coverture in Japan. However, the applicability of this treatment for remnant gastric cancer (RGC) is unclear because the lymphatic flow and lymphatic metastatic pattern may have been changed after initial gastrectomy. There are no guidelines for splenic hilar nodal dissection for RGC. In this study we evaluated risk factors for #10 nodal metastasis in RGC. Methods: This study retrospectively examined RGC patients who received gastrectomy with #10 nodal dissection after distal gastrectomy at two high-volume cancer centers in Japan between 1998 and 2015. Results: 99 patients were entered in this study. The #10 nodal metastatic rate was 12.1% (12/99). Initial gastrectomy was performed for benign in 42 patients and for malignant in 52 patients. The median duration from the initial gastrectomy was 20 (1-55) years. Main tumor location was lesser curvature in 46 patients, anterior wall in 11, greater curvature in 19, posterior wall in 11, and the whole in 12. Large type 3(≥8cm) and type 4 were found in 18 cases. The median tumor size was 50 (10-232) mm. The depth of invasion was cT1 in 31 patients, cT2 in 19, cT3 in 11, cT4a in 28, and cT4b in 10. Histology was differentiated type in 46 patients and undifferentiated type in 56. Completion gastrectomy was performed in 98 patients and partial gastrectomy in 1. 89 patients underwent splenectomy. The univariate analysis showed that tumor location (lesser curvature vs others, p=0.027) and depth of invasion (cT1-3 vs cT4, p=0.032) were significant risk factors for #10 nodal metastasis. By multivariate analysis, these two factors remained significant. Metastasis to #10 nodal metastasis was 0% (0/28) in patients without both risk factors, 11-12% in those with at least one risk factor, and 30% (6/20) in those with both risk factors. Conclusions: The tumors not confined to the lesser curvature and cT4 were significant risk factors for #10 nodal metastasis of RGC after distal gastrectomy. Splenectomy should be considered for complete splenic hilar nodal dissection when these risk factors are positive.

Molecular profiling of hepatoid adenocarcinoma and adenocarcinoma with enteroblastic differentiation.

394 Background: Hepatoid adenocarcinoma (HAD) and adenocarcinoma with enteroblastic differentiation (ACED) are rare types of gastric cancer that produce alpha-fetoprotein (AFP) and morphologically resemble liver or fetal gut cells. The molecular characteristics of these tumors are poorly understood. We aimed to investigate the molecular profile of HAD and ACED in the comparison with common type of gastric cancer. Methods: We analyzed tissue and blood samples from 496 patients who underwent gastrectomy for gastric cancer and participated in the Project HOPE (High-tech Omics-based Patient Evaluation) in our hospital, from 2014 to 2019. We excluded patients with other special types of gastric cancer, remnant gastric cancer and preoperative chemotherapy. We analyzed gene mutation, copy number, and gene expression between 10 HAD/ACED and 486 common types of gastric cancers. Results: The mutated genes with high frequency (&gt; 20%) in HAD/ACED were TP53 (100%) CSMD3 (30%), LRP1B, FAT3, TG, APOB, CREBBP, PASK, DROSHA and STK40 (20%). The tumor mutation burden (TMB) of all the cases were less than 10. TMB of HAD/ACED was equivalent to that of common type of gastric cancer with microsatellite stable type. The copy number of 20q13.2 encoding SALL4 was significantly gained in HAD/ACED ( p = 0.03). Furthermore, 17 genes were highly expressed in these tumors, and many of these genes were associated with hepatocytes and fetal organs, including LIN28B, IGF2BP1, and HMGA2, which are related to TP53 mutation. Conclusions: Our molecular profiling revealed similarities between HAD/ACED and hepatocytes/fetal organs and high expression of LIN28B, IGF2BP1 and HMGA2, which are associated with TP53 inactivation. These results suggest that these genes may define morphological features of HAD/ACED.

Metachronous remnant gastric cancer after proximal gastrectomy.

260 Background: Proximal gastrectomy is frequently selected for early gastric cancer located at the upper third of the stomach. Annual postoperative endoscopy is considered to be useful for the early detection of metachronous remnant gastric cancer (MRGC). Despite that, we sometimes have also encountered cases that are not suitable for endoscopic resection (ER). The aim of this study is to identify the risk factors for the patients who developed MRGC after proximal gastrectomy, received annual endoscopy, but are not eligible for ER (non-ER). Methods: We retrospectively analyzed 191 patients who had received annual endoscopic surveillance after undergoing PG for cT1 gastric cancer at NCCH between 2006-2015. MRGCs were categorized into two groups: ER group and non-ER group. The remnant stomach was defined as three locations: pseudo-fornix (PF), corpus and antrum. Results: The median observation period was 73 (range 12-168) months. MRGC was observed in 29 cases with 32 lesions. ER was eligible for 20 lesions (ER group, 62.5%), but 12 were not (non-ER group, 37.5%). We compared the characteristics between of ER group and non-ER group in terms of sex, age (&gt;65 years), interval from the initial surgery (&gt;60months), the location (PF vs non-PF), and cross-sectional circumference (posterior wall vs. others). In both univariate and multivariate logistic regression analysis, only the location at PF was identified as a risk factor for non-ER group (OR 25.0, 95% CI: 1.8–339, p = 0.015). Among 12 lesions of the non-ER group, the location of PF was found in 6 (50%) lesions. As compared with MRGC at the non-PF, that at the PF (n = 6) was characterized by younger patients (57.5 (range 37-69) years vs. 69 (56-77) years), larger size (36 (7-57) mm vs. 9 (9-24) mm), deeper depth (MP or deeper; 5/6 vs. 0/6), more frequent undifferentiated-type histology (4/6 vs. 0/6) and frequent nodal metastasis (3/6 vs. 0/6). The interval to detect MRGC appears to be longer in the PF (78 (31-96) months than that of the non-PF (60 (31-96) months), but the difference was not statistically significant (p = 0.86). Then, we examined the visibility and the mucosal normality of the area developing MRGC in the annual follow-up endoscopy one year before the detection of MRGC (n =32). In 25 lesions at the non-PF, the visibility and the mucosal normality was secured in 21 (84%). while 5 PF lesions were difficult to observe (71.4%, p = 0.01) due to food residues in 4 (57%, p = 0.047) and insufficient expansion of the gastric mucosa in 4 (57%, p = 0.001). Conclusions: Detection of the MRGC at the PF at an early stage is crucial and challenging. With annual follow-up endoscopy, complete clearance and adequately extending the gastric mucosa could lead to the early detection of MRGC at the PF.

Incidence and risk of remnant gastric cancer after gastrectomy for gastric cancer: a population-based study from the SEER database.

Gastric cancer (GC) constitutes a major global health problem, of which remnant gastric cancer (RGC) occurs less frequently. The rate of RGCs after gastrectomy for GC is increasing recently due to improved survival and screening, however, their incidence and risk have not been reported in the U.S. The objective of this study was to evaluate the incidence and elevated risk of RGC after GC gastrectomy in this population, and to identify the risk factors. Patients underwent gastrectomy for first primary GC in 2000-2015 and those who developed RGC were identified from Surveillance, Epidemiology and End Results (SEER) database. Fine-Gray regression was used to estimate the cumulative incidence and to identify risk factors. Standardized incidence ratios (SIRs) were calculated by Poisson regression to compare the risk with the general population. Among 21,566 patients included in the cohort, 227 developed RGC. The 20-year cumulative incidence of RGC was 1.88%. Multivariate analysis revealed that older age, invasion depth, male sex, marital status, and lower income are independent risk factors for RGC development. SIR was 7.70 overall and > 4.5 in each stratum. Cumulative incidence and risk for RGCs increased continuously in patients underwent GC gastrectomy. Close and lifelong endoscopy surveillance should be recommended for patients who received GC gastrectomy, especially those with high-risk factors.

Characteristics of Metachronous Remnant Gastric Cancer After Proximal Gastrectomy: A Retrospective Analysis.

Despite annual endoscopy, patients with metachronous remnant gastric cancer (MRGC) following proximal gastrectomy (PG) are at times ineligible for endoscopic resection (ER). This study aimed to clarify the clinical risk factors for ER inapplicability. We reviewed the records of 203 patients who underwent PG for cT1 gastric cancer between 2006 and 2015. The remnant stomach was categorized as a pseudofornix, corpus, or antrum. Thirty-two MRGCs were identified in the 29 patients. Twenty MRGCs were classified as ER (ER group, 62.5%), whereas 12 were not (non-ER group, 37.5%). MRGCs were located in the pseudo-fornix in 1, corpus in 5, and antrum in 14 in the ER group, and in the pseudo-fornix in 6, corpus in 4, and antrum in 2 in the non-ER group (P=0.019). Multivariate analysis revealed that the pseudo-fornix was an independent risk factor for non-ER (P=0.014). In the non-ER group, MRGCs at the pseudo-fornix (n=6) had more frequent undifferentiated-type histology (4/6 vs. 0/6), deeper (≥pT1b2; 6/6 vs. 2/6) and nodal metastasis (3/6 vs. 0/6) than non-pseudo-fornix lesions (n=6). We examined the visibility of the region developing MRGC on an annual follow-up endoscopy one year before MRGC detection. In seven lesions at the pseudofornix, visibility was only secured in two (28.6%) because of food residues. Of the 25 lesions in the non-pseudo-fornix, visibility was secured in 21 lesions (84%; P=0.010). Endoscopic visibility increases the chances of ER applicability. Special preparation is required to ensure the complete clearance of food residues in the pseudo-fornix.

Risk factors for remnant gastric cancer after distal gastrectomy for gastric cancer: a retrospective database review.

The number of patients with remnant gastric cancer (RGC) following gastrectomy for gastric cancer (GC) is increasing due to the increasing number of patients undergoing function-preserving gastrectomy and improved outcomes for patients with GC. A few studies involving a small number of cases reported male sex, old age, differentiated type, tumor depth and synchronous multiple GC were associated with RGC development. However, the risk factors for RGC development had not been fully understood. This study aimed to examine the clinicopathological features, followed up patients with GC after they underwent distal gastrectomy (DG), and evaluated the potential risk factors for RGC development. A retrospective database review of 438 patients who underwent DG for GC at a single institution, from 2006 to 2017, was conducted. We investigated the relationship of clinicopathological features, operative findings, and postoperative course with RGC development was estimated using Cox proportional hazard analysis. The cumulative incidences of RGC were calculated using the Kaplan-Meier method. We retrospectively analyzed 405 cases. The median patient age was 69 years, and the patient cohort consisted of 263 men and 142 women. The Billroth-I reconstruction method was used in 204 cases, Billroth-II method was used in 3 cases, and Roux-en Y method was used in 198 cases. RGC was diagnosed in 11 of the 405 patients. The median follow-up period was 5 years. The cumulative incidences of RGC calculated by the Kaplan-Meier method were 3.0%, 4.1%, and 10.5% at 5, 10, and 15 years after DG, respectively. During the initial surgery, differentiated type was significantly associated with RGC development [hazard ratio (HR): 4.71, 95% confidence interval (CI): 1.02-21.80, P=0.05]. Male sex (HR: 2.97, 95% CI: 0.64-13.75, P=0.16), old age (≥70 years) (HR: 2.72, 95% CI: 0.78-9.47, P=0.11), and synchronous multiple GC (HR: 1.31, 95% CI: 0.28-6.08, P=0.73) were not associated with RGC development. Patients who have undergone DG for differentiated type GC were statistically significantly associated with developing RGC. Intensive endoscopic surveillance would be needed for the patients who underwent DG for differentiated type GC.

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

IntroductionGastric 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. MethodsRetrospective 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). Results78 (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. ConclusionsNumbers 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.