Circumventing drug resistance in gastric cancer: A spatial multi-omics exploration of chemo and immuno-therapeutic response dynamics.

BACKGROUND: Gastric Cancer (GC) characteristically exhibits heterogeneous responses to treatment, particularly in relation to immuno plus chemo therapy, necessitating a precision medicine approach. This study is centered around delineating the cellular and molecular underpinnings of drug resistance in this context. METHODS: We undertook a comprehensive multi-omics exploration of postoperative tissues from GC patients undergoing the chemo and immuno-treatment regimen. Concurrently, an image deep learning model was developed to predict treatment responsiveness. RESULTS: Our initial findings associate apical membrane cells with resistance to fluorouracil and oxaliplatin, critical constituents of the therapy. Further investigation into this cell population shed light on substantial interactions with resident macrophages, underscoring the role of intercellular communication in shaping treatment resistance. Subsequent ligand-receptor analysis unveiled specific molecular dialogues, most notably TGFB1-HSPB1 and LTF-S100A14, offering insights into potential signaling pathways implicated in resistance. Our SVM model, incorporating these multi-omics and spatial data, demonstrated significant predictive power, with AUC values of 0.93 and 0.84 in the exploration and validation cohorts respectively. Hence, our results underscore the utility of multi-omics and spatial data in modeling treatment response. CONCLUSION: Our integrative approach, amalgamating mIHC assays, feature extraction, and machine learning, successfully unraveled the complex cellular interplay underlying drug resistance. This robust predictive model may serve as a valuable tool for personalizing therapeutic strategies and enhancing treatment outcomes in gastric cancer.

Prognostic effects of the gastric mucosal microbiota in gastric cancer.

Gastric cancer (GC) is one of the most common malignant tumors with a high incidence and mortality. Microbiota play a significant role in human health and disease. We aimed to investigate the prognostic value of the gastric microbiota in different stomach microhabitats. We used our previously published 16S rRNA gene sequence data. We retrospectively enrolled a cohort of 132 patients with GC with complete prognostic information and selected 78 normal tissues, 49 peritumoral tissues, and 112 tumoral tissues for microbiota analysis. Patients with different prognoses showed different gastric microbiota compositions and diversity. The association network of the abundant gastric microbiota was more complicated in patients with poor prognoses. In the peritumoral microhabitat of patients with good prognoses, Helicobacter was significantly increased, whereas Halomonas and Shewanella were significantly decreased relative to that in the peritumoral microhabitat of patients with poor prognoses. PiCRUSt analysis revealed that the peritumoral microbiota had more different Kyoto Encyclopedia of Genes and Genomes pathways than did the tumoral and normal microbiota. This study evaluated the long-term prognostic value of the gastric mucosal microbiota in patients with GC. These findings suggested that the characteristic alterations of the gastric mucosal microbiota may be markers for clinical outcomes in these patients.

HOXC10 indicates poor survival outcome in gastric cancer and promotes G1/S cell cycle transition through transcriptional repression of p21.

Homeobox (HOX) genes encode proteins that function as transcription factors during embryogenesis and tumorigenesis. We have previously reported upregulation of HOXC10 in gastric cancer (GC) tissues using cDNA microarray analysis. Though the functional role of HOXC10 in GC has been briefly reported, its specific mechanism is not fully understood. We analyzed the expression of HOXC10 in GC tissues, as well as its correlation with the survival outcome. By in vitro and in vivo assays, we further investigated the role of HOXC10 on cell cycle control and proliferation. Finally, we screened potential downstream targets of HOXC10 by cDNA microarray and explored the role of HOXC10 in p21 transcriptional repression through a dual luciferase reporter and chromatin immunoprecipitation. We illustrated the upregulation of HOXC10 in GC tissues and high HOXC10 expression related to poor survival outcome. Multivariable COX regression analysis showed that HOXC10 was an independent predictor of survival (HR=1.863; 95% CI: 1.076-3.225). Functionally, HOXC10 could promote GC cell proliferation and tumor growth in nude mice. Overexpression of HOXC10 accelerated G1/S cell cycle transition, whereas knocking down HOXC10 induced cell cycle arrest at the G1 phase. Critical factors of G1/S cell cycle transition including p21, CDK2, and c-Myc, were regulated by HOXC10. Importantly, an inverse correlation between p21 and HOXC10 expression in GC cell lines and tissues was observed. HOXC10 could directly bind to the promoter region of p21 and repress its transcriptional activity. Collectively, we identified HOXC10 as a predictor of poor prognosis in GC patients, and a novel transcriptional regulator of p21 in the G1/S cell cycle transition.

MiR-129-5p induces cell cycle arrest through modulating HOXC10/Cyclin D1 to inhibit gastric cancer progression.

MicroRNAs (miRNAs) play important roles in posttranscriptional regulation and may serve as targets for the diagnosis and treatment of cancers. Nevertheless, a comprehensive understanding of miRNAs profiles in gastric cancer progression is still lacking. Here, we report that miR-129-5p is downregulated in gastric cancer by analyzing TCGA database (n = 41) and clinical tumor samples (n = 60). MiR-129-5p transfection suppressed gastric cancer cell proliferation through inducing G1 phase arrest in vitro and inhibit xenograft tumor growth in vivo. MiR-129-5p directly targeted the 3' untranslated regions (3' UTR) of HOXC10 mRNA and downregulated its expression. Importantly, miR-129-5p could reverse the oncogenic effect induced by HOXC10. We systemically screened the downstream target of HOXC10 by ChIP sequencing, and found that HOXC10 could transcriptionally regulate the expression of Cyclin D1 and facilitate G1/S cell cycle transition. Notably, high levels of HOXC10 and Cyclin D1 were related with poor prognosis of gastric cancer patients (n = 90). These findings reveal a novel role of miR-129-5p/HOXC10/Cyclin D1 axis in modulating cell cycle and gastric tumorigenesis, which might provide potential prognostic biomarkers and therapeutic targets for gastric cancer patients.

Value of the prognostic nutritional index in advanced gastric cancer treated with preoperative chemotherapy.

BACKGROUND: The prognostic nutritional index (PNI) is a useful parameter indicating the immune and nutritional status of cancer patients; this study investigated the prognostic value of the PNI in advanced gastric cancer patients treated with preoperative chemotherapy. MATERIALS AND METHODS: We retrospectively reviewed 117 advanced gastric cancer patients who met the inclusion criteria for preoperative chemotherapy and underwent surgical resection from July 2004 to December 2011. The patients were divided into PNI-high (PNI ≥ 45) and PNI-low (PNI < 45) groups. Clinicopathologic features, chemotherapy adverse events, and surgical complications were compared between the prechemotherapy PNI-high and PNI-low groups using the chi-square test. Survival analysis was performed using the Kaplan-Meier method and log-rank test. The Cox proportional hazard model was used to identify prognostic factors. RESULTS: Overall survival was better in the prechemotherapy PNI-high group than in the PNI-low group (hazard ratio [HR] = 2.237, 95% confidence interval [CI]: 1.271-3.393, P = 0.005), while there was no significant difference in Overall survival between the postchemotherapy PNI-high and PNI-low groups (P > 0.05). Cox regression analysis indicated that yield pathologic T (ypT), yield pathologic N (ypN) stage, and prechemotherapy PNI were independent prognostic factors (ypT: HR = 2.914, 95% CI = 1.312-6.470, P = 0.009; ypN: HR = 4.909, 95% CI = 1.764-13.660, P = 0.003; prechemotherapy PNI: HR = 1.963, 95% CI = 1.101-3.499, P = 0.022). CONCLUSIONS: The prechemotherapy PNI is a useful predictor of the long-term outcome of patients with advanced gastric cancer treated with preoperative chemotherapy.

Role of plasmacytoid dendritic cells and inducible costimulator-positive regulatory T cells in the immunosuppression microenvironment of gastric cancer.

Regulatory T cells (Tregs) and plasmacytoid dendritic cells (pDCs) play important roles in the immune escape of cancer. In this study, we investigated pDCs and pDC-induced inducible costimulator (ICOS)(+) Treg populations in peripheral blood from gastric cancer (GC) patients and healthy donors by flow cytometry. The distribution of these cells in carcinoma tissue, peritumor tissue, and normal gastric mucosa was detected by immunohistochemistry. Plasma and tissue concentration of the cytokines such as interleukin-10 and transforming growth factor-ß1 were also measured. We found that the numbers of pDCs, Tregs, and ICOS(+) Tregs in peripheral blood were increased in GC patients compared with healthy donors. In tissue, Tregs and ICOS(+) Tregs were found distributing mainly in carcinoma tissue, whereas pDCs were mainly found in peritumor tissue. Moreover, the Foxp3(+) ICOS(+) /Foxp3(+) cell ratio in carcinoma and peritumor tissue were higher than that in normal tissue. There were more ICOS(+) Tregs in tumor and peritumor tissue of late-stage GC patients. There was a positive correlation between pDCs and ICOS(+) Tregs in peripheral blood and peritumor tissue from GC patients. In conclusion, pDCs may play a potential role in recruiting ICOS(+) Tregs, and both participate in the immunosuppression microenvironment of GC.

B cells present a double-sided effect in digestive system tumors: a review for tumor microenvironment.

Over the past few years, there has been an increasing interest in investigating tumor-infiltrating lymphocytes. B lymphocytes (B cells) are extensively distributed within tertiary lymphoid structure (TLS) as multifaceted subgroups and are intimately linked to the anti-tumor properties of TLS, as well as the survival and prognostication of individuals. While the investigation of T lymphocytes in the TLS has advanced to the level of clinical practice, the study of B cells remains limited. The principal impediment to the utilization of B cells in immunotherapy is their notable dual impact on tumors. Compared with tumors in other parts and systems, the function of B cells in the microenvironment of digestive system tumors to promote tumors proliferation, differentiation and migration cannot be ignored. Therefore, this review collects the studies of B cell subsets in tumor microenvironments, particularly related single cell sequencing research. The multifaceted role and function of B cells are investigated in esophageal, liver, colorectal, gastric and pancreatic cancers. And through the identification of B cell subsets and specific markers, this review attempts to explain the reasons why B cells produce different tumor-promoting effects in those tumors. The insights gleaned from this review may provide potential help and support the development of B cell-based immunotherapies.

Blood neutrophil-lymphocyte ratio predicts survival for stages III-IV gastric cancer treated with neoadjuvant chemotherapy.

BACKGROUND: Accurate predictors of survival for patients with advanced gastric cancer treated with neoadjuvant chemotherapy are currently lacking. In this study, we aimed to evaluate the prognostic significance of the neutrophil-lymphocyte ratio (NLR) in patients with stage III-IV gastric cancer who received neoadjuvant chemotherapy. METHODS: We enrolled 46 patients in this study. The NLR was divided into two groups: high (>2.5) and low (≤2.5). Univariate analysis on progression-free survival (PFS) and overall survival(OS) was performed using the Kaplan-Meier and log-rank tests, and multivariate analysis was conducted using the Cox proportional hazards regression model. We analyzed whether chemotherapy normalized high NLR or not, and evaluated the prognostic significance of normalization on survival. RESULTS: The univariate analysis showed that PFS and OS were both worse for patients with high NLR than for those with low NLR before chemotherapy (median PFS 16 and 49 months, respectively, P = 0.012; median OS 21 and 52 months, P = 0.113). PFS and OS were also worse for patients with high NLR than for those with low NLR before surgery (median PFS 12 and 35 months, P = 0.019; median OS 21 and 52 months, P = 0.082). Multivariate analysis showed that both NLR before chemotherapy and surgery were independent prognostic factors of PFS. Neoadjuvant chemotherapy normalized high NLR in 11 of 24 patients, and these 11 patients had better median PFS and OS than the 13 patients who had high NLR both before chemotherapy and before surgery (PFS: 35.0 and 10.0 months, P = 0.003; OS: 60 and 16 months, P = 0.042). CONCLUSIONS: NLR may serve as a potential biomarker for survival prognosis in patients with stage III-IV gastric cancer receiving neoadjuvant chemotherapy.

Anti-tumor effects of Mfn2 in gastric cancer.

Mitofusin-2 (Mfn2) is a mitochondrial outer membrane protein involved in mitochondrial fusion. Its mutation can cause Charcot-Marie-Tooth disease. Recent studies of Mfn2 in cancer research have not included gastric cancer. We confirmed that Mfn2 expression was lower in tumor tissue than in normal gastric mucosal tissue and that it was negatively correlated with tumor size, indicating an anti-tumor role for Mfn2. In vitro experiments showed that Mfn2 overexpression suppressed gastric cancer cell proliferation and colony formation, weakened the invasion and migratory ability of cancer cells by downregulating MMP-2 and MMP-9, halted the cell cycle and induced apoptosis. Western blotting indicated the likely involvement of P21 and PI3K/Akt signaling. Therefore, Mfn2 is a potential anti-tumor gene and a potential therapeutic target for treating gastric cancer. The progress of gastric cancer may be delayed by controlling Mfn2 expression.

Advances in the diagnosis of non-occlusive mesenteric ischemia and challenges in intra-abdominal sepsis patients: a narrative review.

Non-occlusive mesenteric ischemia (NOMI) is a type of acute mesenteric ischemia (AMI) with a high mortality rate mainly because of a delayed or misdiagnosis. Intra-abdominal sepsis is one of the risk factors for developing NOMI, and its presence makes early diagnosis much more difficult. An increase in routine abdominal surgeries carries a corresponding risk of abdominal infection, which is a complication that should not be overlooked. It is critical that physicians are aware of the possibility for intestinal necrosis in abdominal sepsis patients due to the poor survival rate of NOMI. This review aims to summarize advances in the diagnosis of NOMI, and focuses on the diagnostic challenges of mesenteric ischemia in patients with intra-abdominal sepsis.

The prognostic role of gastrointestinal bleeding in patients with a primary gastrointestinal stromal tumor: a long-term follow-up study.

Background: Gastrointestinal (GI) bleeding is one of the common symptoms of GI stromal tumor (GIST). Although several studies have highlighted its prognostic role, conclusions have been inconsistent. This study aimed to investigate the prognosis of GIST patients with GI bleeding. Methods: Primary GIST patients who underwent complete resection and did not receive adjuvant imatinib therapy from January 2003 to December 2008 were reviewed. The Kaplan-Meier method was used to estimate recurrence-free survival (RFS), and multivariate analysis was performed using the Cox proportional hazard model. Propensity score matching (PSM) was conducted to reduce confounders. A systematic review of the published articles in the PubMed, Embase, Cochrane Collaboration, and Medline databases was also conducted, and the inclusion criteria were determined using PICOS (patients, intervention, comparison, outcomes, and study design) principles. Results: In total, 84 patients presenting with GI bleeding and 90 patients without GI bleeding were enrolled in this study. The median time of follow-up was 140 months (range, 10-196 months), and 38 patients developed tumor recurrence/metastasis. For all patients, the multivariate analysis indicated that tumor location [hazard ratio (HR) =3.48, 95% confidence interval (CI): 1.78-6.82, P<0.001], tumor size (HR =1.91, 95% CI: 1.05-3.47, P=0.035), mitotic index (MI; HR =5.69, 95% CI: 2.77-11.67, P<0.001), and age (HR =2.68, 95% CI: 1.49-4.82, P=0.001) were the independent prognostic factors for poor RFS. However, GI bleeding was not associated with RFS (HR =1.21, 95% CI: 0.68-2.14, P=0.518). After PSM, 45 patients from each group were included, and it was found that GI bleeding was still not the independent prognostic factor (HR =1.23, 95% CI: 0.51-2.97, P=0.642). Moreover, the pooled results of our study and six previously reported studies showed that GI bleeding was not the independent prognostic factor (HR =1.45, 95% CI: 0.73-2.86, P=0.287). Conclusions: In this study, tumor location, tumor size, MI, and age were independent prognostic factors in primary GIST patients who underwent radical resection. However, GI bleeding was not associated with worse RFS.

CCR9-CCL25 mediated plasmacytoid dendritic cell homing and contributed the immunosuppressive microenvironment in gastric cancer.

OBJECTIVES: Plasmacytoid dendritic cells (pDCs) play a crucial role in the microenvironment of tumor. Evidences has been shown that chemokine receptor 9 (CCR9) is an important molecule that attracts pDCs homing to the digestive tract and the latter are involved in the formation of digestive tract immune tolerance. The aim of this study was to explore the role of CCR9-CCL25 interaction in pDC-mediated immunosuppression microenvironment of gastric cancer (GC). MATERIALS AND METHODS: Regulatory T cells (Tregs) and pDCs were detected by immunohistochemistry. CCR9, which expressed on pDC was visualized by immunofluorescence. Western Blot was applied to evaluate the expression of CCL-25. Total pDCs, CCR9+pDCs, CCR9-pDCs, total Tregs, inducible costimulator + (ICOS) Tregs and ICOS-Tregs in peripheral blood and draining lymph nodes were analyzed by flow cytometry. Plasma concentration of the cytokines were measured by enzyme-linked immunosorbent assay RESULTS: Total Tregs, pDCs and CCR9+pDCs were higher in GC tissue. CCL-25 was over-expressed in carcinoma tissue. Peripheral total pDCs, CCR9-pDCs, total Tregs, ICOS+ Tregs, ICOS- Tregs were significantly increased in GC patients. More total pDCs, CCR9+ pDCs, total Tregs, ICOS+ Tregs were found in metastatic lymph nodes. Plasma concentrations of IL-6 and IL-10 were significantly higher in GC patients. More CCR9+ pDCs were found infiltrating carcinoma tissue in patients with later T staging and lymph node metastasis and conferred a poor prognosis. CONCLUSION: CCR9-CCL25 interaction might play an important role in mediating PDC homing to metastatic lymph nodes and carcinoma tissue, which contributed to the formation of tumor immunosuppressive microenvironment and poor prognosis.

Tolerance induction towards cardiac allografts under costimulation blockade is impaired in CCR7-deficient animals but can be restored by adoptive transfer of syngeneic plasmacytoid dendritic cells.

Deficiency of transplant recipients for the chemokine receptor CCR7 was originally described to slightly increase the survival time of vascularized solid organ grafts, probably due to a reduced priming of alloreactive T cells. Using a model of allotolerance induction by donor-specific splenocyte transfusion (DST) in combination with anti-CD40L mAb-mediated costimulation blockade (CSB), we show here a striking failure of CCR7-deficient (CCR7(-/-) ) recipients to tolerate cardiac allografts. Furthermore, in addition to the recently described lack of Treg, CCR7(-/-) mice were found to harbor significantly reduced numbers of plasmacytoid dendritic cells (pDCs) within peripheral as well as mesenteric lymph nodes (LNs), but not the bone marrow or spleen. pDCs had previously been suggested to function as tolerogenic APC during allograft transplantation, and a single transfer of syngeneic WT pDCs, but not conventional DCs, was indeed sufficient to rescue graft survival in DST+CSB-treated CCR7(-/-) recipients in a dose-dependent manner. We therefore conclude that the nearly complete absence of pDCs within LNs of CCR7(-/-) mice prevents the successful induction of DST+CSB-mediated allotolerance, leading to the observed acute rejection of cardiac allografts under tolerizing conditions.

Intra- and intercompartmental movement of gammadelta T cells: intestinal intraepithelial and peripheral gammadelta T cells represent exclusive nonoverlapping populations with distinct migration characteristics.

Unlike the ∼1% of γδ TCR-positive T cells being regularly present in blood and secondary lymphoid organs (peripheral γδ T cells), ∼50-60% of small intestinal intraepithelial lymphocytes (iIELs) in the mouse express the γδ TCR (γδ iIELs). In this study, we investigated the overlap and exchange of γδ iIELs and γδ T cells found in peripheral secondary lymphoid organs. Using two-photon laser-scanning microscopy, we found γδ T cells within peripheral lymph nodes to be highly motile, whereas γδ iIELs were characterized by a locally confined scanning behavior. Our results implied a strict separation of peripheral γδ T cells and γδ iIELs. Nevertheless, γδ iIELs could be efficiently regenerated from bone marrow-derived precursors in irradiated or T cell-deficient adult mice. However, outside the intestinal epithelium, survival of γδ iIELs was very poor. In CCR9-deficient mice, homing of γδ iIELs was impaired, but did not lead to an accumulation of γδ iIEL-like cells in the periphery. Conversely, in situations in which specific γδ iIEL niches were empty, adoptive transfer of isolated γδ iIELs led to a sustained engraftment of transferred γδ iIELs in the intestinal epithelium for at least 100 d. Furthermore, we demonstrated by heterotopic intestinal transplantation experiments that an exchange of γδ iIELs only rarely happens in the steady state of adult mice. We therefore conclude that peripheral versus intestinal intraepithelial γδ T cells are exclusive, nonoverlapping populations that virtually do not exchange with each other.

Effect of S-1 Plus Oxaliplatin Compared With Fluorouracil, Leucovorin Plus Oxaliplatin as Perioperative Chemotherapy for Locally Advanced, Resectable Gastric Cancer: A Randomized Clinical Trial.

IMPORTANCE: Perioperative chemotherapy is a potential treatment for locally advanced gastric cancer. However, the optimal chemotherapy regimen remains unknown. OBJECTIVE: To investigate the safety and efficacy of S-1 plus oxaliplatin (SOX) vs fluorouracil, leucovorin, and oxaliplatin (FOLFOX) as a perioperative chemotherapy regimen for patients with locally advanced gastric cancer. DESIGN, SETTING, AND PARTICIPANTS: In this phase 3, open-label, multicenter, randomized clinical trial, patients from 12 Chinese hospitals were enrolled between June 2011 and August 2016, with a last follow-up date of September 2019. The primary tumor was evaluated as either invading the serosa or the adjacent structures with or without metastatic lymph nodes, and with no evidence of distant metastases. Data were analyzed from December 2019 to June 2020. INTERVENTIONS: Patients were randomly assigned (1:1) to receive either 6 perioperative (2-4 preoperative and 2-4 postoperative) 3-week cycles of 130 mg/m2 oxaliplatin on day 1 and 80 to 120 mg/d S-1 orally daily for 2 weeks (SOX) or 130 mg/m2 oxaliplatin, 400 mg/m2 fluorouracil, 400 mg/m2 leucovorin, and 2400 mg/m2 fluorouracil as 46-hour infusion on day 1 (FOLFOX). MAIN OUTCOMES AND MEASURES: The primary end point was 3-year overall survival (OS). An absolute noninferiority margin of -8% was chosen. RESULTS: A total of 583 patients were enrolled; 293 were randomized to the SOX group and 290 were randomized to the FOLFOX group. Twelve patients (2.1%) refused preoperative chemotherapy (5 patients in the SOX group and 7 patients in the FOLFOX group), leaving a total of 288 patients in the SOX group (median [range] age, 61 [24 to 78] years; 197 men [68.4%]) and 283 patients in the FOLFOX group (median [range] age, 62 [24 to 80] years; 209 men [73.9%]) who received preoperative chemotherapy. The 3-year OS rate was 75.2% (95% CI, 70.3% to 80.5%) in the SOX group and 67.8% (95% CI, 62.5% to 73.5%) in the FOLFOX group. The absolute difference of 3-year OS rate between the 2 groups was 7.4% (95% CI, -0.1% to 14.9%), which was greater than the prespecified noninferiority margin (-8%) and showed the noninferiority of perioperative chemotherapy with SOX compared with FOLFOX. CONCLUSIONS AND RELEVANCE: In this randomized clinical trial, SOX was noninferior to FOLFOX as perioperative chemotherapy for patients with locally advanced gastric cancer and could be recommended as an alternative treatment for these patients in Asia. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01364376.

Role of the Gastric Microbiome in Gastric Cancer: From Carcinogenesis to Treatment.

The development of sequencing technology has expanded our knowledge of the human gastric microbiome, which is now known to play a critical role in the maintenance of homeostasis, while alterations in microbial community composition can promote the development of gastric diseases. Recently, carcinogenic effects of gastric microbiome have received increased attention. Gastric cancer (GC) is one of the most common malignancies worldwide with a high mortality rate. Helicobacter pylori is a well-recognized risk factor for GC. More than half of the global population is infected with H. pylori, which can modulate the acidity of the stomach to alter the gastric microbiome profile, leading to H. pylori-associated diseases. Moreover, there is increasing evidence that bacteria other than H. pylori and their metabolites also contribute to gastric carcinogenesis. Therefore, clarifying the contribution of the gastric microbiome to the development and progression of GC can lead to improvements in prevention, diagnosis, and treatment. In this review, we discuss the current state of knowledge regarding changes in the microbial composition of the stomach caused by H. pylori infection, the carcinogenic effects of H. pylori and non-H. pylori bacteria in GC, as well as the potential therapeutic role of gastric microbiome in H. pylori infection and GC.

The Prognostic Value of Lymph Node Ratio after Neoadjuvant Chemotherapy in Patients with Locally Advanced Gastric Adenocarcinoma.

PURPOSE: This study aimed to investigate the prognostic value of lymph node ratio (LNR) in patients with locally advanced gastric cancer who received neoadjuvant chemotherapy. MATERIALS AND METHODS: We retrospectively enrolled gastric cancer patients treated with neoadjuvant chemotherapy and curative surgery at the First Affiliated Hospital of Zhejiang University from 2004 to 2015 as the study cohort. Patients with the same inclusion criteria treated in 2016-2017 were enrolled as the validation cohort. Kaplan-Meier curves were assessed using the log-rank test to analyze the differences in overall survival (OS). Multivariate survival analysis was performed using the Cox proportional hazards model. The areas under the receiver operating characteristic curve of ypN and LNR categories for predicting the actual 3-year OS were compared. RESULTS: A total of 265 patients were included in the proposal cohort. The median number of retrieved lymph nodes (rLNs) was 32. The number of positive lymph nodes (pLNs) increased as rLN increased (P=0.037), but the LNR remained relatively constant (P=0.462). The LNR was categorized into 4 groups according to the prognosis: ypNr0, node-negative with rLN>25; ypNr1, node-negative with rLN≤25 or 00.3. In the validation cohort of 43 enrolled patients, there was a clear distinction in OS that significantly (P<0.001) varied depending on the LNR values and LNR was the only independent prognostic factor in multivariate analysis (P<0.001). CONCLUSIONS: LNR was an independent prognostic factor for survival of patients with gastric cancer after preoperative chemotherapy and might be an alternative predictor for ypN stage.