Machine learning models for prediction of lymph node metastasis in patients with T1b gastric cancer.

The prognosis of early gastric cancer (EGC) patients is associated with lymph node metastasis (LNM). Considering the relatively high rate of LNM in T1b EGC patients, it is crucial to determine the factors associated with LNM. In this study, we constructed and validated predictive models based on machine learning (ML) algorithms for LNM in patients with T1b EGC. Data from patients with T1b gastric cancer were extracted from the Korean Gastric Cancer Association database. ML algorithms such as logistic regression (LR), random forest (RF), extreme gradient boosting (XGBoost), and support vector machine (SVM) were applied for model construction utilizing five-fold cross-validation. The performances of these models were assessed in terms of discrimination, calibration, and clinical applicability. Moreover, external validation of XGBoost models was performed using the T1b gastric cancer database of The Catholic University Medical Center. In total, 3,468 T1b EGC patients were included in the analysis, whom 550 (15.9%) had LNM. Eleven variables were selected to construct the models. The LR, RF, XGBoost, and SVM models were established, revealing area under the receiver operating characteristic curve values of 0.8284, 0.7921, 0.8776, and 0.8323, respectively. Among the models, the XGBoost model exhibited the best predictive performance in terms of discrimination, calibration, and clinical applicability. ML models are reliable for predicting LNM in T1b EGC patients. The XGBoost model exhibited the best predictive performance and can be used by surgeons for the identification of EGC patients with a high-risk of LNM, thereby facilitating treatment selection.

Surgical outcomes and prognosis of intracorporeal versus extracorporeal esophagojejunostomy after laparoscopic total gastrectomy for gastric cancer: a propensity score-matching study.

This study compared the surgical outcomes and long-term prognosis of intracorporeal and extracorporeal esophagojejunostomy after laparoscopic total gastrectomy (LTG) for gastric cancer patients. In total 228 clinical stage I gastric cancer patients undergoing LTG were enrolled from January 2012 and December 2022. Each case in the totally laparoscopic total gastrectomy (TLTG) group was 1:1 propensity score-matched to control cases in the laparoscopy-assisted total gastrectomy (LATG) group. In total, 95 and 93 LATG and TLTG patients were included after propensity score matching (PSM). Clinicopathological features, surgical outcomes, and survival variables were compared, and risk factors for postoperative complications were analyzed. Patient characteristics were well balanced between the LATG and TLTG groups after PSM. The TLTG group showed less blood loss, decreased frequency of analgesic use, and shorter duration of analgesic use. The TLTG group had significantly lower rates of intestinal obstruction and surgical site infection. Larger tumor size and advanced pTNM stage were independent risk factors for postoperative complications. There was no significant difference in overall survival (OS). Compared with LATG, TLTG was associated with better surgical outcomes and fewer postoperative surgical complications in gastric cancer patients although there was no significant difference in OS.

Lifestyle Behaviors in Patients With Gastric Cancer: Continuous Need for Alcohol Abstinence and Muscle Strength Training Education.

PURPOSE: This study was performed to assess the lifestyle-related behaviors of patients with gastric cancer (GC) and to investigate the associations between the time since GC diagnosis and these behaviors. MATERIALS AND METHODS: This study included 29,478 adults (including 338 patients with GC) aged ≥ 40 years who participated in the Korea National Health and Nutrition Examination Survey 2014-2021. Multiple logistic regression analysis explored the associations between the time since GC diagnosis (patients diagnosed with GC less than 5 years ago [<5 years group] and those diagnosed with GC 5 or more than years ago [≥5 years group]) and lifestyle factors. Subgroup analyses were conducted based on age and sex. RESULTS: The current smoking rate was not lower in the GC group than in the healthy group, regardless of time since diagnosis. Compared to the healthy controls, monthly alcohol intake was lower in the <5 years group (odds ratio [OR], 0.450; 95% confidence interval [CI], 0.275-0.736). The ≥5 years group showed a lower rate of strength training (OR, 0.548; CI, 0.359-0.838), compared with the healthy control group. Subgroup analysis focusing on the ≥5 years group revealed a significantly lower rate of strength training, particularly in patients aged ≥65 years and male patients (OR, 0.519 and 0.553; CI, 0.302-0.890 and 0.340-0.901, respectively). CONCLUSIONS: Clinicians should continue educating patients on lifestyle behavior modifications, particularly alcohol abstinence, even beyond 5 years after GC diagnosis. Education on strength training is especially important for patients ≥65 years or male patients.

Prognostic effect of microscopically negative but close resection margin in gastric cancer.

INTRODUCTION: Microscopically positive resection margin (RM) following curative surgery has been linked to disease recurrence in gastric cancer (GC), but the impact of microscopically negative but close RM (CRM) remains unclear. This study aimed to evaluate the prognostic implications of a CRM of ≤0.5 cm in GC patients. METHODS: A retrospective review of the institutional GC database identified 1958 patients who underwent curative gastrectomy for pathologically proven GC between January 2011 and December 2015. The patients were categorized into CRM (RM ≤0.5 cm) and sufficient RM (SRM, RM >0.5 cm) groups. The impact of CRM on recurrence-free survival (RFS) and overall survival (OS) was analyzed compared to the SRM group. RESULTS: The cohort comprised 1264 patients with early GC (EGC, 64.6%) and 694 with advanced GC (AGC, 35.4%). Forty-four patients (2.2%) had RM of ≤0.5 cm. CRM was associated with worse RFS in AGC (5-year RFS in the CRM vs. SRM groups; 41.6% vs. 68.7%, p = 0.011); however, the effect on OS was not significant (p = 0.159). Multivariate analysis revealed that CRM was an independent prognostic factor for RFS (hazard ratio [HR] 2.035, 95% confidence interval [CI] 1.097-3.776). In AGC, the locoregional recurrence rate was significantly higher in the CRM group than in the SRM group (15.4% vs. 4.9%, p = 0.044). CONCLUSION: CRM of ≤0.5 cm was a significant prognostic factor for RFS in GC patients and was associated with a significant increase in locoregional recurrence in AGC.

Food passage following proximal gastrectomy with double-tract reconstruction and its effect on nutritional status in early gastric cancer: a prospective single-center cohort study.

Purpose: Laparoscopic proximal gastrectomy with double-tract reconstruction (LPG-DTR) expectedly results in improved nutritional status and less body weight loss than conventional total gastrectomy in upper-third gastric cancer. This study aimed to investigate the food passage patterns following LPG-DTR and its effect on nutritional outcomes up to 1 year after surgery. Methods: This prospective cohort study recruited 10 patients with early gastric cancer scheduled for LPG-DTR. Nutritional indices and body composition were assessed every 3 months up to 12 months. Liquid and solid food transits were evaluated with fluoroscopic upper gastrointestinal study and radionuclide scintigraphy, respectively. Results: At 12 months, patients exhibited a body weight loss of 14.5% ± 3.6%. The main passage routes for liquid and solid foods differed, primarily via the interposed jejunum for liquids, whereas via both tracts for solids. The median half-life of solid food emptying from the remnant distal stomach was 105.1 minutes (range, 50.8-2,194.2 minutes), and duodenal passage of solid food was noted in 9 of 10 patients. Those with gastric half-emptying time >3 hours demonstrated greater weight loss (19.5% ± 1.4% vs. 12.5% ± 1.1%, P = 0.024) and more pronounced reduction in serum albumin levels (-0.5 ± 0.3 g/dL vs. 0.0 ± 0.2 g/dL, P = 0.024) after 12 months. Conclusion: LPG-DTR demonstrated varying food passage patterns depending on the food contents and delayed solid food emptying from the remnant stomach was associated with more substantial weight loss.

Gastric perforation after polyurethane foam ingestion.

INTRODUCTION: Acute intoxication rarely produces conditions that require urgent surgical care. CASE SUMMARY: A 45-year-old man presented to the emergency department with severe abdominal pain after the deliberate ingestion of 200 cm3 of polyurethane mixed with methylene diphenyl diisocyanate and urethane primers. On an initial laparoscopic examination, foreign material was observed in the peritoneal space with haemoperitoneum. Emergency exploration was then undertaken for suspected gastric perforation. Full-thickness damage was identified on the stomach wall during the operation. The material in the gastrointestinal tract and peritoneal space was gently removed. Moulded casts of the entire stomach and distal oesophagus were extracted successfully. The patient was discharged 14 days after surgery. IMAGES: Computed tomography revealed foreign material occupying the entire gastric chamber, as well as diffuse gastric perforation. CONCLUSIONS: Life-threatening gastric perforation can occur after polyurethane foam ingestion. Clinical/medical toxicologists and emergency physicians need to be aware of the highly expandable nature of this agent.

Comparison of the Prognosis of Upper-Third Gastric Cancer With That of Middle and Lower-Third Gastric Cancer.

PURPOSE: Gastric cancer is one of the most common cancers in Korea, and the proportion of upper-third gastric cancers has been steadily increasing over the last two decades. This study aimed to evaluate the effect of tumor location on gastric cancer prognosis. MATERIALS AND METHODS: We retrospectively reviewed 2,466 patients who underwent gastrectomy for pathologically proven gastric cancer between January 2011 and December 2016. The patients were divided into an upper-third group (U group; n=419, 17.0%) and a middle- and lower-third group (ML group; n=2,047, 83.0%). Clinicopathological characteristics, overall survival (OS), and recurrence-free survival (RFS) after surgery were compared. RESULTS: The U group had more advanced disease than the ML group and a higher incidence of N3b disease for T3 (12.0% vs. 4.9%, p=0.023) and T4 tumors (33.3% vs. 17.5%, p=0.001). The 5-year RFS rate for stage III disease was marginally lower in the U group than that in the ML group (47.1% vs. 56.7%, p=0.082). The upper third location was an independent prognostic factor for both OS (hazard ratio [HR], 1.350; 95% confidence interval [CI], 1.065-1.711) and RFS (HR, 1.430; 95% CI, 1.080-1.823). CONCLUSIONS: Upper-third gastric cancer shows extensive node metastasis compared to those located more distally in ≥T3 tumors. The upper third location is an independent prognostic factor for both OS and RFS and may have an adverse impact on RFS, particularly in patients with stage III gastric cancer.

Pyrolysis of biomass harvested from heavy-metal contaminated area: Characteristics of bio-oils and biochars from batch-wise one-stage and continuous two-stage pyrolysis.

This study evaluates pyrolysis products obtained from biomasses (silver grass, pine, and acacia) harvested from heavy-metal-contaminated soil. To do so, we utilized two methods: a batch one-stage pyrolysis, and a continuous two-stage pyrolysis. The study results show that the yields and characteristics of bio-oils and biochars varied depending on the pyrolysis process and the type of biomass. The two-stage pyrolysis having two reactors (auger and fluidized bed reactors) appeared to be very suitable for specific chemicals production such as acetic acid, acetol, catechol, and levoglucosan. The biochar obtained from the fluidized-bed reactor of two-stage pyrolysis had high thermal stability, high crystallinity, high inorganic content, and a small number of functional groups. In contrast, the biochar obtained from the one-stage pyrolysis had low thermal stability, low crystallinity, a high carbon content, and a large number of functional groups. The biochar obtained from the two-stage pyrolysis appeared to be suitable as a material for catalyst support and as an adsorbent. The biochar obtained from one-stage pyrolysis appeared to be a suitable as a soil amendment, as an adsorbent, and as a precursor of activated carbon. All biochars showed a negative carbon footprint. In the end, this study, which was conducted using two different processes, was able to obtain the fact that products of pyrolysis biomass contaminated with heavy metals have different characteristics depending on the process characteristics and that their utilization plans are different accordingly. If the optimal utilization method proposed through this study is found, pyrolysis will be able to gain importance as an effective treatment method for biomass contaminated with heavy metals.

Refining gastric cancer staging: examining the interplay between number and anatomical location of metastatic lymph nodes - a retrospective multi-institutional study.

BACKGROUND: The current gastric cancer staging system relies on the number of metastatic lymph nodes (MLNs) for nodal stage determination. However, incorporating additional information such as topographic status may help address uncertainties. This study evaluated the appropriateness of the current staging system and relative significance of MLNs based on their anatomical location. METHODS: Patients who underwent curative gastrectomy for gastric cancer between 2000 and 2019 at six Catholic Medical Center-affiliated hospitals were included. Lymph node-positive patients were classified into the perigastric (stations 1-6, group P) or extragastric (stations 7-12) groups. The extragastric group was further subdivided into the near-extragastric (stations 7-9, group NE) and far-extragastric (stations 10-12, group FE) groups. RESULTS: We analyzed the data of 3,591 patients with positive lymph node metastases. No significant survival differences were found between group P and the extragastric group in each N stage. However, in N1 and N2, group FE showed significantly worse survival than the other groups (p = 0.013 for N1, p < 0.001 for N2), but not in N3. In the subgroup analysis, group FE had a significantly lower overall survival in N2, regardless of the cancer location. CONCLUSIONS: Our large-scale multi-institutional big data analysis confirmed the superiority of the current numerical nodal staging system for gastric cancer. Nonetheless, in N1 and N2 in which there is an upper limit on metastatic nodes, attention should be paid to the potential significance of topographic information for specific nodal stations.

Surgical outcomes and survival of patients over 80 years old who underwent curative resection for gastric cancer.

Purpose: Among patients with gastric cancer who underwent radical gastrectomy, the proportion of patients aged ≥80 years has increased. This study aimed to evaluate surgical outcomes and survival of patients aged ≥80 years who underwent curative resection for gastric cancer and identify independent factors that affect postoperative survival. Methods: This retrospective study enrolled 1,066 patients aged ≥65 years with gastric cancer who underwent curative resection between January 2014 and December 2018 at a single institution. They were divided into those aged ≥80 years (old-elderly group) and 65-79 years (young-elderly group). Their clinicopathological characteristics and surgical outcomes were compared. Results: Of the 1,066 patients, 136 (12.8%) were 80 years or older. Higher American Society of Anesthesiologists (ASA) physical status classification and more advanced cancers were observed in the old-elderly group than in the young-elderly group. No significant difference in postoperative complications was found between the groups. At a median follow-up of 49.1 months, the 5-year overall survival rate after surgery for the old-elderly group was lower than that for the young-elderly group (75.6% vs. 87.0%, P < 0.001). However, the 5-year disease-specific survival rate was comparable between the groups (90.1% vs. 92.2%, P = 0.324). ASA physical status classification, pathologic stage, and surgical approach were independent predictors of overall survival. Conclusion: Old-elderly patients aged ≥80 years had comparable postoperative outcomes and disease-specific survival to the young-elderly group, suggesting that curative gastrectomy can be considered a viable option for octogenarian patients with gastric cancer.

Genetic landscape and PD-L1 expression in Epstein-Barr virus-associated gastric cancer according to the histological pattern.

Epstein-Barr virus (EBV)-associated gastric cancer (EBVaGC) is a distinct molecular subtype of gastric cancer. This study aims to investigate genomic and clinicopathological characteristics of EBVaGC according to the histological pattern. We retrospectively collected 18 specimens of surgically resected EBVaGCs. Whole-exome sequencing was performed for all cases. Moreover, PD-L1 expression and tumor-infiltrating lymphocyte (TIL) percentage were investigated. Among 18 EBVaGCs, 10 cases were of intestinal histology, 3 were of poorly cohesive histology, and the remaining 5 were of gastric carcinoma with lymphoid stroma histology. Whole-exome sequencing revealed that EBVaGCs with intestinal histology harbored pathogenic mutations known to frequently occur in tubular or papillary adenocarcinoma, including TP53, KRAS, FBXW7, MUC6, ERBB2, CTNNB1, and ERBB2 amplifications. One patient with poorly cohesive carcinoma histology harbored a CDH1 mutation. Patients with EBVaGCs with intestinal or poorly cohesive carcinoma histology frequently harbored driver mutations other than PIK3CA, whereas those with EBVaGCs with gastric carcinoma with lymphoid stroma histology lacked other driver mutations. Moreover, the histological pattern of EBVaGCs was significantly associated with the levels of TILs (P = 0.005) and combined positive score (P = 0.027). In conclusion, patients with EBVaGCs with different histological patterns exhibited distinct genetic alteration, PD-L1 expression, and degree of TILs.

Is single incision laparoscopic surgery (SILS) for gastric gastrointestinal stromal tumor (GIST) dependent on the location of the tumor?

BACKGROUND: We compared the surgical outcomes of single-incision laparoscopic surgery (SILS) and conventional laparoscopic surgery (CLS) for gastric gastrointestinal stromal tumor (GIST). METHODS: We performed single-incision gastric wedge resection on prospectively-enrolled 15 consecutive patients with gastric GIST between November 2020 and April 2022 in a single tertiary center. The early perioperative outcomes of these patients were compared to those of patients who underwent CLS. The indications did not differ from those for conventional laparoscopic procedures for gastric GIST. RESULTS: In total, 30 patients were assigned to the SILS (n = 15) and CLS (n = 15) groups. There were no significant differences in the estimated blood loss and intraoperative blood transfusion between the SILS and CLS groups. There were no intraoperative complications or conversions to multiple-port or open surgery in the SILS group. Proximally located tumors were more commonly treated with CLS than with SILS (P = 0.045). GISTs located in the greater curvature were more commonly treated with SILS than with CLS, although the difference was not statistically significant (P = 0.08). The mean incision length in the SILS group was 4.1 cm shorter than that in the CLS group (3.2 ± 0.7 and 7.3 ± 5.2 cm, respectively, P = 0.01). The postoperative analgesic dose was significantly lower in the SILS than in the CLS group (0.4 ± 1.4 and 2.1 ± 2.3, respectively P = 0.01). Also, the duration of postoperative use of analgesic was shorter in SILS than in CLS (0.4 ± 0.7 and 2.0 ± 1.8, respectively, P = 0.01). There were no significant differences in the early postoperative complications between the groups. CONCLUSIONS: SILS is as safe, feasible, and effective for the treatment of gastric GIST as CLS with comparable postoperative complications, pain, and cosmesis. Moreover, SILS can be considered without being affected by the type or location of the tumor.

Clinical implications and chemo-sensitivity of adjuvant chemotherapy in patients with poorly cohesive cells-gastric cancer.

PURPOSE: Poorly cohesive cells-gastric cancer (PCC-GC) represents distinct features within the GC spectrum. The present study investigated the clinicopathologic characteristics and chemo-sensitivity for a relatively large cohort of PCC-GC patients. MATERIALS AND METHODS: A total of 268 patients diagnosed with stage II or III PCC-GC were included. GC cell lines were also analyzed for drug sensitivity to 5-fluorouracil (5-FU) and oxaliplatin in vitro. RESULTS: One hundred fifteen (42.9%) patients were stage II and 153 (57.1%) were stage III. Two hundred twenty-three (83.2%) patients received adjuvant therapy. Among these patients, 139 (62.3%) received CAPOX and 84 (37.7%) received S-1. With a median follow-up of 38.9 (1.6-137.8) months, the estimated 5-year disease-free survival (DFS) and overall survival (OS) rates were 52.3% and 61.0%, respectively. In the univariate analysis, survival was significantly better in the adjuvant chemotherapy group than in the surgery only group. In the subgroup analysis, there was no significant difference in DFS or OS between the types of adjuvant chemotherapy for either disease stage. In vitro cell line analysis, different responses to 5-FU and oxaliplatin were observed in SRC and non-SRC, where the treatment in KATOIII cell lines with oxaliplatin had less effect at a higher concentration compared to non-SRC cell lines. CONCLUSION: The current study found that adjuvant chemotherapy was not significantly associated with survival benefit for patients with resected stage II and III PCC-GC. Plus, S-1 showed numerically longer DFS and OS compared to CAPOX in PCC-GC patients, although no significant in the multivariate analysis.

Gastric cancer with distinct Epstein-Barr virus-positive and -negative tumor components and their whole exome sequencing result: a case Report.

BACKGROUND: Epstein-Barr virus (EBV)-associated gastric cancer exhibits distinct clinicopathologic characteristics, showing a good response to immune checkpoint inhibitors and a favorable prognosis. However, gastric cancer comprising distinct EBV-positive and -negative components in a single mass have been rarely reported, and their detailed genetic characteristics have not yet been investigated. Therefore, we reported the case of gastric cancer exhibiting distinct EBV-positive and -negative areas and further investigated its genetic characteristics. CASE PRESENTATIONS: A 70-year-old man underwent distal gastrectomy for gastric cancer, which was detected during a routine health check-up. EBV-encoded RNA in situ hybridization revealed distinct EBV-positive and -negative components at each other's borders, morphologically consistent with collision tumor. We separately sequenced EBV-positive and -negative tumor areas through whole exome sequencing (WES) with matched normal tissue. Remarkably, both EBV-positive and -negative areas shared pathogenic mutations of ARID1A, KCNJ2, and RRAS2. Furthermore, they shared 92 somatic single nucleotide variants and small insertion or deletion mutations, of which 32.7% and 24.5% are EBV-positive and -negative tumor components, respectively. CONCLUSIONS: WES results suggested that gastric cancer with distinct EBV-positive and -negative tumor components, formerly categorized as a collision tumor, can be clonally related. EBV-negative tumor component might be associated with loss of EBV during tumor progression.

Abdominal compartment syndrome caused by severe acute gastric distension in a patient with COVID-19: A case report.

RATIONALE: The clinical manifestation of coronavirus disease 2019 (COVID-19) ranges from asymptomatic to critical. The gastrointestinal (GI) tract is involved in the early stages of the disease and is recognized as an important entry site for the virus. Consequently, GI manifestations are common in patients with COVID-19; however, the GI presentation of COVID-19 in relation to bowel dilatation has rarely been reported. Here, we report a case of acute severe gastric distension resulting in aortic compression and abdominal compartment syndrome (ACS) in a patient with COVID-19. PATIENT CONCERNS: A 72-year-old male presented to the emergency department (ED) with severe abdominal distension. The patient had been confirmed to have COVID-19 5 days prior to the visit. DIAGNOSES: Computed tomography revealed critical abdominal distension with severe gastric dilatation, accompanied by compression of the abdominal aorta and distal thrombosis formation. INTERVENTIONS: Intravenous fluid resuscitation and support with inotropic agents were initiated immediately, and a large amount of gastric content was evacuated via a nasogastric (NG) tube. OUTCOME: Finally, the patient was discharged after 12 days of admission without obvious complications. LESSONS: ACS is critical, which can be caused by a severe degree of acute gastric distension (AGD). Evacuation of the intraluminal contents is the most efficient management strategy. Prognosis is poor, and most previous studies of the transition from AGD to ACS have reported unfavorable outcomes.

Does Epstein-Barr virus-positive gastric cancer establish a significant relationship with the multiple genes related to gastric carcinogenesis?

Gastric cancer has been categorized into molecular subtypes including Epstein-Barr virus (EBV)-positive tumors, which provide clinicopathological and prognostic information. In this study, we investigated the EBV infection status of patients with gastric cancer and its correlation with the clinicopathological characteristics and multiple genes related to gastric carcinogenesis. The data of 460 gastric cancer patients who underwent curative gastrectomy with D2 lymph node dissection between January 2017 and February 2022 were analyzed. The clinicopathological features and prognosis of the patients with EBV-positive gastric cancers were compared with those of EBV-negative gastric cancers. Immunohistochemistry for epidermal growth factor receptor (EGFR), C-erb B2, Ki-67, and p53 was performed. Additionally, in situ hybridization was conducted to detect EBV, and microsatellite instability (MSI) analysis was used to assess the deficiency in mismatch repair (MMR) genes. EBV-positivity and MSI were identified in 10.4% and 37.3% of gastric cancer patients, respectively. EBV positivity was associated with male gender (P = 0.001), proximal location (P = 0.004), poorly differentiated histological type (P = 0.048), moderate to severe lymphoid stroma (P = 0.006), high Ki-67 expression (P = 0.02), and a shorter resection margin. EGFR was more often expressed in EBV-negative gastric cancers (P < 0.001). MSI tumors were associated with older age (P = 0.01), the presence of lymphatic invasion (P = 0.02), less perineural invasion (P = 0.05), and the presence of H. pylori infection (P = 0.05). EBV positive gastric cancer is associated with increased Ki-67 and decreased EGFR expression and a shorter resection margin due to the prominent lymphoid stroma. However, MMR deficiency is not associated with EBV status even though MSI gastric cancer is related to H. pylori status.

Predictive model for long-term weight recovery after gastrectomy for gastric cancer: an introduction to a web calculator.

BACKGROUND: Weight changes after gastrectomy affect not only quality of life but also prognosis and survival. However, it remains challenging to predict the weight changes of individual patients. Using clinicopathological variables, we built a user-friendly tool to predict weight change after curative gastrectomy for gastric cancer. METHODS: The clinical data of 984 patients who underwent curative gastrectomy between 2009 and 2013 were retrospectively reviewed and analyzed. Multivariate logistic regression was performed to identify variables predictive of postoperative weight change. A nomogram was developed and verified via bootstrap resampling. RESULTS: Age, sex, performance status, body mass index, extent of resection, pathological stage, and postoperative weight change significantly influenced postoperative weight recovery. Postoperative levels of hemoglobin, albumin, ferritin and total iron-binding capacity were significant covariates. The nomogram performed well (concordance index = 0.637); calibration curves indicated appropriate levels of agreement. We developed an online weight prediction calculator based on the nomogram ( http://gc-weightchange.com/en/front/ ). CONCLUSIONS: The novel, Web-calculator based on the predictive model allows surgeons to explore patient weight patterns quickly. The model identifies patients at high risk for weight loss after gastrectomy; such patients require multidisciplinary medical support.