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BACKGROUND Mismatch repair-deficient (dMMR) or microsatellite instability-high (MSI-H) status serves as a predictor of a poor response to adjuvant chemotherapy among stage 2 colon cancer patients. This study aimed to investigate the efficacy of adjuvant chemotherapy in dMMR/MSI-H gastric cancer (GC). METHODS Clinical studies comparing adjuvant chemotherapy and surgery alone in dMMR/MSI-H GCs through June 2021 were retrieved to assess the survival of patients managed with both treatments. Two approaches were used to pool the hazard ratio (HR) of survival: (1) if Kaplan-Meier curves and number of patients at risk were provided, individual patient data were extracted. Cox models were used to calculate the HR with its 95% confidence interval (CI); (2) for study-level data, pooled HR was estimated using fixed/random-effects models. RESULTS Seven clinical studies were assessed. For dMMR/MSI-H versus mismatch repair-proficient (pMMR)/microsatellite stable (MSS)/microsatellite instability-low (MSI-L) status, the estimated 5-year disease-free survival (DFS) rate was 74.2% versus 51.5% (HR, 0.44; 95% CI, 0.32-0.62; P < 0.001) and the estimated 5-year OS rate was 60.5% versus 49.1% (HR, 0.71; 95% CI, 0.60-0.85; P < 0.001). The study-level data showed pooled HRs of 0.42 for DFS (95% CI, 0.31-0.57; P < 0.001) and 0.65 for OS (95% CI, 0.38-1.11; P = 0.114). For adjuvant chemotherapy versus observation of dMMR/MSI-H, the estimated 5-year DFS rate was 76.1% versus 73.3% (HR, 0.72; 95% CI, 0.45-1.15; P = 0.171) and the estimated 5-year OS rate was 73.5% versus 59.7% (HR, 0.62; 95% CI, 0.46-0.83; P = 0.001). Significant survival differences also were observed at study level. CONCLUSIONS The study findings confirm the benefit of adjuvant chemotherapy for dMMR/MSI-H GC patients. more...

Background Due to its limited efficacy and potential toxicity, anti-PD-1 monoclonal antibody is not suitable for all advanced gastric cancer (AGC) patients and predictive biomarkers identifying patients who can benefit from it are urgently needed. This study aimed to evaluate the predictive and prognostic value of inflammatory markers in the context of the systemic inflammatory status and tumour microenvironment. Methods The study included 58 patients from a prospective study investigating the safety and efficacy of toripalimab in chemorefractory AGC patients. Patient characteristics, treatment outcomes, and haematological parameters were analysed. Immune-cell infiltration and gene expression in tumour tissue were examined using transcriptome sequencing. Results In this cohort, the median follow-up time was 4.5 months, the median progression-free survival was 1.9 months, and the median overall survival (OS) was 4.8 months. The objective response rate was 12.1% and th disease control rate (DCR) was 39.7%. Both the baseline blood neutrophil-to-lymphocyte ratio (bNLR) with a cut-point of 2.7 and the early elevated dynamic change of the bNLR (dNLR) with a cut-point of 1.5 were prognostic factors of survival. Patients in the high bNLR or dNLR group had remarkably poor DCR (25.8% vs 59.1%, P = 0.023; 15.8% vs 54.6%, P = 0.008). In multivariate analysis, bNLR and tumour mutational burden were independent prognostic factors of OS. Tumour RNA-seq analysis revealed enriched neutrophil infiltration and a higher tumour NLR in the bNLR-high group. Corresponding tumour gene-expression profiles were associated with neutrophil recruitment and inflammatory cytokine aggregation. Conclusions Our study demonstrated the potential clinical utility of NLR as a biomarker for patient selection and clinical management in predicting the prognosis of AGC patients as well as response to anti-PD-1 therapy. In addition, high bNLR reflected the imbalance of tumour-tissue-infiltrating neutrophils and lymphocytes, and was associated with an immunosuppressive and pro-tumour microenvironment. more...

Background Epstein-Barr virus (EBV)-associated gastric carcinomas (EBVaGCs) present unique molecular signatures, but the tumorigenesis of EBVaGCs and the role EBV plays during this process remain poorly understood. Methods We applied whole-exome sequencing, EBV genome sequencing, and whole-genome bisulfite sequencing to multiple samples (n = 123) derived from the same patients (n = 25), which covered saliva samples and different histological stages from morphologically normal epithelial tissues to dysplasia and EBVaGCs. We compared the genomic landscape between EBVaGCs and their precursor lesions and traced the clonal evolution for each patient. We also analyzed genome sequences of EBV from samples of different histological types. Finally, the key molecular events promoting the tumor evolution were demonstrated by MTT, IC50, and colony formation assay in vitro experiments and in vivo xenograft experiments. Results Our analysis revealed increasing mutational burden and EBV load from normal tissues and low-grade dysplasia (LD) to high-grade dysplasia (HD) and EBVaGCs, and oncogenic amplifications occurred late in EBVaGCs. Interestingly, within each patient, EBVaGCs and HDs were monoclonal and harbored single-strain-originated EBV, but saliva or normal tissues/LDs had different EBV strains from that in EBVaGCs. Compared with precursor lesions, tumor cells showed incremental methylation in promotor regions, whereas EBV presented consistent hypermethylation. Dominant alterations targeting the PI3K-Akt and Wnt pathways were found in EBV-infected cells. The combinational inhibition of these two pathways in EBV-positive tumor cells confirmed their synergistic function. Conclusions We portrayed the (epi) genomic evolution process of EBVaGCs, revealed the extensive genomic diversity of EBV between tumors and normal tissue sites, and demonstrated the synergistic activation of the PI3K and Wnt pathways in EBVaGCs, offering a new potential treatment strategy for this disease. more...

Supplemental Digital Content is available in the text., Despite that immune checkpoint inhibitors (ICIs) had tremendous improved the survival of multiple solid tumors, only a limited proportion of patients are responsive to ICIs. Therefore, effective variables are urgently needed to predict the probability of response to ICIs. Systematic searches were conducted from inception up to May, 2020. Prospective or retrospective studies of ICIs that investigated the association between body mass index (BMI) and survival outcomes, including overall survival (OS) and/or progression-free survival (PFS), were selected. The association between each BMI category and survival outcomes was calculated using Cox proportional hazard regression models and quantified as hazard ratio (HR) with corresponding 95% confidence interval. Seven clinical studies involving data from 3768 individual patients were included. The median OS was 15.5 months (95% confidence interval: 14.7–16.2 mo) and the median PFS was 5.7 months (5.2–6.3 mo). The median OS was significantly longer in overweight/obese patients than in nonoverweight patients (20.7 vs. 11.3 mo; P more...

Objectives. Recent trials have shown an overall survival (OS) benefit in 10-40% advanced cancer patients treated with programmed cell death 1 (PD-1) or programmed death-ligand 1 (PD-L1) inhibitors. Here, we aimed to evaluate the relationship between PD-L1 expression and the therapeutic efficacy of PD-1 or PD-L1 inhibitors in patients with cancer with recurrent or metastatic disease, compared with control treatments. Methods. We systematically searched Medline (PubMed), Embase, and Cochrane Library databases up to Jan 2019 and pooled the treatment effects (hazard ratio or relative ratio) of PD-1/PD-L1 inhibitors in patients with different PD-L1 expression. Results. Overall, twenty-four qualifying trials with over 14,860 subjects were eligible in this study. Compared with conventional agents, anti-PD/PD-L1 drugs significantly reduced the risk of death (hazard ratio 0.72, 95% CI 0.66 to 0.78), irrespective of the tumor type. Additionally, when PD-L1 expression ≥1% was defined as positive, anti-PD-1/PD-L1 monotherapy correlated with prolonged overall survival in patients with nonsmall cell lung cancer (NSCLC) (0.72, 0.61 to 0.86) and other cancer types (0.66, 0.57 to 0.76) patients with PD-L1 positive, rather than those with PD-L1 negative (hazard ratio for NSCLC and other cancer types: 0.84 and 0.87, respectively; all P > 0.05 ). The subgroup analyses to experimental agents, PD-1/PD-L1 inhibitors, PD-L1 antibody clone, and type of IHC scoring method validated the robustness of these findings. However, anti-PD-1/PD-L1 combination therapies can reduce the risk of death for patients with different cancer types, regardless of PD-L1 expression ( P < 0.05 for all PD-L1 expression status). Conclusions. We recommend PD-L1 expression as a predictive biomarker in patient selection for anti-PD-1/PD-L1 monotherapy, but not for combination therapies. more...

Background: Dysregulation of prostate stem cell antigen (PSCA) has been implicated in human cancers. Studies have reported that PSCA expression is generally high in prostate cancer, which correlates with a worse survival. PSCA is also highly expressed in bladder, ovarian, and pancreatic cancers. However, PSCA is expressed at low levels in gastric, gallbladder and oesophageal cancers. At present, the clinical significance, expression pattern and biological function of PSCA in gastric cancer (GC) are still unclear. Methods: Previously, we used cDNA microarray as a screening tool to compare GC tissues with its matched normal gastric mucosa tissues (MNGT), and obtained the differentially expressed genes of the two tissue types. PSCA is one of the genes significantly down-regulated in GC tissues. In this study, we detected the expression of PSCA in GC tissues and MNGT by western-blot experiment and immunohistochemical staining (IHC). Then the relationship between the expression pattern of PSCA and the clinicopathological characteristics and survival in GC was analyzed. In order to further study the function of PSCA in GC, lentivirus was used to construct stable cell lines with knockdown and overexpression of PSCA gene. We used AGS and MKN45 cell lines for plasmid transfection. Colony formation assay, MTS and nude mice xenograft model were performed to investigate the effect of PSCA in GC. Results: Western-blot and IHC assays demonstrated that the expression of PSCA in GC tissues was significantly lower than that in the MNGT. PSCA expression in GC tissues was high in 252 (57.5%) and low in 186 (42.5%) of 438 patients. PSCA expression for MNGT was high in 273 (62.3%) and low in 165 (37.7%) of 438 patients. PSCA expression was significantly associated with T classification (P=0.024), N classification (P=0.018) and TNM stage (P=0.019) using χ2 test. The relationship between PSCA expression level and patient survival was analysed using Kaplan-Meier analysis and the log-rank test. Low levels of PSCA expression were significantly associated with a poorer OS than high expression levels of PSCA (P=0.011). In the COX regression analysis of OS, all 9 variables in the univariate analysis were significantly correlated with OS (P more...

This study aimed to construct immune-related predictors to identify responders to anti-PD1 therapy of melanoma through CIBERSORT algorithm. Using the least absolute shrinkage and selection operator (LASSO) logistic regression, we constructed an immunoscore consisting of 8 immune subsets to predict the anti-PD1 response. This score achieved an overall accuracy of AUC = 0.77, 0.80 and 0.73 in the training cohort, validation cohort and on-anti-PD1 cohort, respectively. Patients with high immunoscores had significantly higher objective response rates (ORRs) than did those with low immunoscores (ORR: 53.8% vs 17.7%, P < 0.001 for entire pre-anti-PD1 cohort; 42.1% vs 15.1%, P = 0.022 for on-anti-PD1 cohort; 66.7% vs 16.7%, P = 0.038 for neoadjuvant anti-PD1 cohort). Prolonged survival trends were observed in high-immunoscore group (1-year PFS: 42.4% vs 14.3%, P = 0.059; 3-year OS: 41.5% vs 31.6%, P = 0.057). Furthermore, we found that high-immunoscore group exhibited higher fractions of tumor-infiltrating lymphocytes and an increased IFN-γ response. Analysis of the results of the GSEA indicated a significant enrichment of antitumor immunity pathways in the high-immunoscore group. Therefore, this study indicated that we constructed a robust immunoscore model to predict the anti-PD1 response of metastatic melanoma and the neoadjuvant anti-PD1 response of resectable melanoma. more...

Background: The benefit of palliative gastrectomy for patients with metastatic gastric cancer (mGC) is controversial, and suitable candidates for surgery and treatment strategies remain unclear. The present study aimed to investigate the efficacy of palliative gastrectomy plus chemotherapy among patients with mGC and to identify the potential patients for such treatment using real-world data. Methods: A dataset of 236 patients with mGC diagnosed at the Sun Yat-Sen University Cancer Center from January 1, 2006 to December 31, 2012 were analyzed retrospectively. The cohort comprised 80 patients who had palliative gastrectomy plus chemotherapy (SC) and 156 patients who had chemotherapy only (CO). Propensity score matching (PSM) was employed to minimize the influence of confounders. Results: The median overall survival of the SC group was significantly better than that of the CO group (Before PSM: 17.0 months vs 12.0 months, P=0.038; after PSM: 17.0 months vs 13.0 months, P=0.017). In the multivariate analysis, SC (Before PSM: hazard ratio (HR) =0.68, P=0.023; after PSM: HR =0.64, P=0.021) was favored for better survival after adjustment for sex, age, year of diagnosis, primary tumor location, and tumor grade. Total gastrectomy (P=0.026) was associated with worse survival for the SC group. The significant survival advantage of SC over CO was retained in patients with single organ metastasis (P=0.016), peritoneal seedings (P=0.039), and those receiving taxane-based chemotherapy (P=0.011). Conclusion: SC could improve the overall survival of patients with mGC as compared with CO. The chemotherapy regimen and type of resection were proven to influence efficacy. Patients who received taxane-based regimens might be suitable for palliative gastrectomy. more...

Background: Increasing numbers of Gastric cancer(GC) patients were diagnosed at younger age with aggressive behavior including early disease recurrence, more frequent peritoneal metastasis and poor overall survival. To investigate the driver genes and mechanisms of the early-onset and more aggressive nature of the GC.Methods: Gastric adenocarcinoma and matched germline samples were obtained from patients in Sun Yat-sen University Cancer Center between 2007 and 2013. Exome sequencing were performed for 198 pairs of primary gastric adenocarcinoma fresh tissue and blood samples from young or elder patients. Besides, matched tumor / blood exome sequencing was performed in 80 patients with peritoneal seeding and 51 patients without. Then bioinformatics analysis was performed to find genomic variants and their clinical meanings.Results: Early-onset gastric cancers (EOGCs) have fewer somatic mutations but some deleterious germline variates in FAT genes, patients carried none, one, two, three of the 4 Single nucleotide polymorphisms (SNPs), the mean ages of diagnosis are 60, 50, 40 and 35 respectively. Somatic mutations in CDH1, TGFBR1 and CTNNB1 are related to early-onset cancers. These variants are all linked to WNT pathways. Somatic mutations in genes involved in cancer aggressiveness like MAP2K7, CDH1 and RhoA are related to cancer progression and metastasis. Patients carrying RhoA, ITGAV, TGFBR1, CDH1, CTNNB1, MYO9B, VAV1, SALL1, CDX4 somatic mutations or simultaneously carrying three FAT germline SNPs have been diagnosed at younger age than those have only TP53 mutations.Conclusions: The molecular characterization gives us a novel insight into the carcinogenesis and tumor progression mechanisms and may provide a guide to developing novel targeted therapy in GC. more...

Background and objective The role of additional gastrectomy after non-curative endoscopic resection remains uncertain. The present meta-analysis aimed to explore the risk factors for early-stage gastric-cancer patients after non-curative endoscopic resection and evaluate the efficacy of additional gastrectomy. Methods Relevant studies that reported additional gastrectomy after non-curative endoscopic resection were comprehensively searched in MedLine, Web of Science and EMBASE. We first investigated the risk factors for residual tumor and lymph-node metastasis after non-curative endoscopic resection and then analysed the survival outcome, including 5-year overall survival (OS) and 5-year disease-free survival, of additional gastrectomy. Results Twenty-one studies comprising 4870 cases were included in the present study. We found that residual tumor was associated with larger tumor size (>3 cm) (odds ratio [OR] = 2.81, P 3 cm) (OR = 1.73, P SM1) (OR = 2.68, P more...

Background: We assessed the surrogacy of objective response rate (ORR), disease control rate (DCR) and progression-free survival (PFS) for overall survival (OS) in anti-PD-1/PD-L1 trials of metastatic melanoma through a meta-analysis of randomized controlled trials (RCTs). Methods: PubMed and EMBASE were searched for phase II/III RCTs till June 2019 investigating anti-PD-1/PD-L1 agents. Treatment effect (hazard ratio or odds ratio) on potential surrogates (ORR/DCR/PFS) and OS were collected. At trial level, we assessed the correlation between treatment effect on potential surrogates and OS, weighted by sample size, fixed and random effect models, and calculated the surrogate threshold effect (STE). Sensitivity analyses and leave-one-out cross-validation approach were performed to evaluate the robustness of our findings. Results: We included 8 RCTs (4110 patients; 11 comparisons). We did not identify strong correlations between ORR [coefficient of determination ( R2): 0.09–0.25], DCR (0.41–0.57) and OS. However, we noted a strong correlation between PFS and OS, with R2 of 0.82 in sample size, 0.75 in fixed effect and 0.72 in random effect model weighting, the robustness of which was further verified by leave-one-out cross-validation approach. Sensitivity analyses with restriction to trials with less than 50% crossover, phase III trials, large trials and first-line trials strengthened the correlation (0.78–0.94). The STE for PFS was 0.78. Conclusions: PFS may be the appropriate surrogate for OS in anti-PD-1/PD-L1 trials of metastatic melanoma. A future anti-PD-1/PD-L1 trial would need less than 0.78 for PFS of the upper limit of confidence interval to predict an OS benefit. more...

Background: We aimed to assess whether disease-free survival (DFS) could serve as a reliable surrogate endpoint for overall survival (OS) in adjuvant trials of pancreatic cancer. Methods: We systematically reviewed adjuvant randomized trials for non-metastatic pancreatic cancer after curative resection that reported a hazard ratio (HR) for DFS and OS. We assessed the correlation between treatment effect (HR) on DFS and OS, weighted by sample size or precision of hazard ratio estimate, assuming fixed and random effects, and calculated the surrogate threshold effect (STE). We also performed sensitivity analyses and a leave-one-out cross validation approach to evaluate the robustness of our findings. Results: After screening 450 relevant articles, we identified a total of 20 qualifying trails comprising 5170 patients for quantitative analysis. We noted a strong correlation between the treatment effects for DFS and OS, with coefficient of determination of 0.82 in the random effect model, 0.82 in the fixed effect model, and 0.80 in the sample size weighting; the robustness of this finding was further verified by the leave-one-out cross-validation approach. Sensitivity analyses with restriction to phase 3 trials, large trials, trials with mature follow-up periods, and trials with adjuvant therapy versus adjuvant therapy strengthened the correlation (0.75 to 0.88) between DFS and OS. The STE was 0.96 for DFS. Conclusions: Therefore, DFS could be regarded as a surrogate endpoint for OS in adjuvant trials of pancreatic cancer. In future similar adjuvant trials, a hazard ratio for DFS of 0.96 or less would predict a treatment impact on OS. more...

Background: To investigate prognostic factors and recurrence patterns in T4 gastric cancer (GC) patients after curative resection. Methods: Between January 2004 and December 2014, 249 patients with T4 gastric cancer undergoing curative resection were recruited. Patient characteristics, survival, prognostic factors and recurrence patterns were analyzed. Results: Our results showed that the median survival time (MST) for T4 gastric cancer after curative resection was 55.47 months, with 59.47 months for T4a (tumor perforating serosa) and 25.90 months for T4b (tumor invasion of the adjacent structure). Multivariate analysis indicated that age (hazard ratio [HR], 1.86; P = 0.006), location of tumor (HR, 1.25, 0.90 - 5.64; P < 0.001) and intraoperative blood loss (HR, 1.85; P = 0.010) were independent prognostic factors for overall survival (OS). After a median follow-up of 25.87 months, a total of 109 (43.8%) patients suffered from recurrence, and 90 patients had been observed specific recurrence sites, among which peritoneal metastasis was the most common recurrence pattern, 59.0% for T4a and 88.3% for T4b, respectively. Conclusions: For T4 gastric cancer patients after curative resection, older age, gastric cancer of the entire stomach and more intraoperative blood loss were associated with poor OS. The recurrence rate after curative resection for T4 was high, and the most common recurrence pattern was peritoneal metastasis. more...

e21511 Background: There remain unmet needs to identify novel immune checkpoint inhibitors to improve the benefit-risk profile of immunotherapy for advanced melanoma. The comparison between LAG3-PD1 inhibition and CTLA4-PD1 inhibition was lacked. To compare the inhibition of lymphocyte-activation gene 3 (LAG3) plus programmed cell death 1 (PD-1) versus the inhibition of cytotoxic T-lymphocyte antigen 4 (CTLA-4) plus PD-1 in patients with previously untreated advanced melanoma. Methods: The individual participant data (IPD) data were extracted from the KM plots using a graphical reconstructive algorithm through eligible. Log-rank, Cox proportional hazard model, Bayesian hierarchical model with time-varying hazard ratio (HR) effect, and restricted mean survival time (RMST) were performed to estimate survival benefits. The primary endpoint was progression-free survival. Results: The CheckMate-067 (N = 630) and RELATIVITY-047 (N = 714) trials were included for analysis. The graphical reconstructive algorithm showed that IPD had similar HRs and log-rank values as the original plots. The HR of nivolumab-relatlimab (LAG3 inhibitor) versus nivolumab-ipilimumab (CTLA4 inhibitor) was 1.19 (95% confidence interval [CI] 0.96 to1.48). The 24-months RMST of nivolumab-relatlimab versus nivolumab alone was 2.35 (95% CI 0.77 to 3.94) months, compared with 1.87 (95% CI 0.25-3.49) months for nivolumab-ipilimumab versus nivolumab. The Bayesian hierarchical model showed that patients treated with nivolumab-relatlimab had earlier PFS benefits than those with nivolumab-ipilimumab. Grade 3 or 4 treatment-related adverse events occurred in 18.9% of patients using nivolumab-relatlimab and 55.0% of patients using nivolumab-ipilimumab. Conclusions: These findings suggest that the PFS of LAG3-PD1 and CTLA4-PD1 inhibition were similar and that LAG3-PD1 inhibition tended to exhibit earlier survival benefit and lesser TRAEs. more...

4054 Background: Circulating tumor DNA (ctDNA) is a promising biomarker for detecting molecular residual disease (MRD) and relapse after definitive treatment in multiple solid cancers. However, the significance of ctDNA is rarely clarified in locoregional gastric cancer (GC). Here, we conducted a prospective and observational study to evaluate the utility of ctDNA in predicting the recurrence risk of GC. Methods: From October 2016 to June 2019, 100 patients with stage II/III resectable GC were recruited in this study (NCT02887612). Primary tumors and plasma samples were collected perioperatively and after adjuvant chemotherapy (ACT). Somatic variants were captured via a targeted sequencing panel of 425 cancer-related genes. The plasma of patients was defined as ctDNA positive only if one or more variants detected in the plasma presented in at least 2% of the primary tumors. All the patients received curative-intent standard-of-care therapy. Results: Preoperative ctDNA was detectable in 38 (38.0%) patients but showed limited value for predicting recurrence. After surgery (median days, 4), the plasma of 25 (25.0%) patients were still ctDNA positive and they had higher recurrence risk than the non-positive patients (hazard ratio [HR], 2.74 (95% CI: 1.37–5.48); P = 0.003). Forty-one patients had evaluable plasma after ACT and 10 (24.4%) of them who were ctDNA positive had remarkably higher recurrence and death risk compared with ctDNA-negative patients (recurrence-free survival [RFS] HR = 14.99 (95% CI: 3.08–72.96); P < 0.001; overall survival HR, 11.88 (95% CI: 2.38–59.24); P < 0.001). In particular, post-ACT ctDNA achieved better predictive performance (sensitivity, 77.8%; specificity, 90.6%) than both postoperative ctDNA and post-treatment tumor biomarkers (i.e., CEA, CA199, and CA72-4). In all multivariate analyses, ctDNA positivity was an independent factor of RFS. Patients with ERBB4 mutation in their primary tumors had poorer RFS compared to those were ERBB4 wildtype (HR = 3.46 (95% CI: 1.32–9.03); P = 0.007). A comprehensive model incorporating ctDNA status for recurrence risk prediction showed a higher concordance index (0.78; 95%CI, 0.71–0.84) than the model without ctDNA status (0.71; 95%CI, 0.64–0.79; P = 0.009). Conclusions: Postoperative and post-ACT ctDNA was associated with MRD and high risk of relapse in patients with stage II/III GC and can be utilized to guide GC management in post-surgical settings. more...

The present study is the first phase II clinical trial aimed to evaluate the efficacy and safety of S-1 plus nanoparticle albumin-bound paclitaxel (Nab-PTX) as first-line chemotherapy for advanced gastric cancer (AGC). Previously untreated patients with metastatic gastric adenocarcinoma received S-1 in oral doses of 40 mg (BSA more...

Background: The US guidelines for gastric cancer (GC) recommend adjuvant radiotherapy (ART) combined with 5-fluorouracil as a standard treatment for patients with resected locally advanced GC. However, patient selection criteria for optimizing the use of adjuvant therapies are lacking. In this study, we developed and validated a nomogram to predict the individualized overall survival (OS) benefit of ART among patients with resected ≥stage IB GC. Patients and Methods: The 2002-2006 Surveillance, Epidemiology, and End Results (SEER) data of 5,206 patients with resected GC were used as a training set for the development of a nomogram. The 2007-2008 SEER data of 1,986 patients with resected GC were used as validation data. Results: In the multivariate analysis weighted by inverse propensity score, the efficacy of ART varied by the ratio of positive to examined nodes (Pinteraction more...

Background and Objectives: Previous studies of the prognostic value of the signet ring cell (SRC) type have yielded inconsistent results. Therefore, the aim of the present meta-analysis is to explore the clinicopathological characteristics and prognostic value of SRCs. Methods: Relevant articles that compared SRC and non-SRC type in PubMed and Web of Science were comprehensively searched. Then, a meta-analysis was performed. Results: A total of 19 studies including 35947 cases were analyzed. Compared with non-SRC patients, SRC patients tended to be younger (WMD: -3.88, P=0.001) and predominantly female (OR: 1.60, P more...

Background: The present study aimed to explore whether gastric cancer patients with peritoneal seeding after receiving palliative chemotherapy could benefit from gastrectomy and to identify patients with peritoneal seeding who should be selected to receive gastrectomy. Methods: A total of 201 gastric cancer patients were diagnosed with peritoneal seeding and received palliative chemotherapy. Propensity score matching (PSM) was performed to balance the selection bias. Results: After PSM, compared with non-gastrectomy group, gastrectomy group had a longer median overall survival (OS) (23.60 vs. 13.80 moths; P=0.034). Patients with R0 resection had a median OS of 43.60 months compared with 11.27 months in patients who underwent R1/2 resection (P more...

Bakcground The recently proposed 8th American Joint Committee on Cancer (AJCC) staging for gastric cancer (GC) did not include the evaluated lymph node (ELN) count as a prognostic indicator. In this study, we performed recursive partitioning analysis (RPA) to objectively combine the 15-ELN threshold and 8th AJCC stage to refine the staging for GC. Methods We analyzed 19,018 patients with non-metastatic GC from the Surveillance, Epidemiology, and End Results database. The dataset was randomly divided into training and validation sets. Results For each 8th AJCC stage, survival was significantly better for patients with ≥15 ELNs versus those with more...

Objectives. To evaluate the efficacy of immuno-oncology combinational therapy (IOCT) versus monotherapy with programmed cell death 1 (PD-1) or PD-ligand 1 (PD-L1) inhibitors or conventional therapies, i.e., non-IOCT, in patients with advanced solid tumors. Methods. We systematically searched the PubMed, Embase, and Cochrane Library databases from January 2015 to October 2018 for eligible studies. We included randomized trials of IOCT with available hazard ratios (HR) for death. The random effects model was used to calculate pooled HR for death; heterogeneity was assessed using I2 statistics. The main outcome measure was overall survival (OS). Results. After screening 483 relevant articles, we identified twelve trials comprising 5388 patients for quantitative analysis. IOCT-treated patients had significantly higher tumor response rate (relative risk (RR): 2.51, 95% confidence interval (CI): 1.82-3.47), prolonged progression-free survival (HR 0.62, 95% CI: 0.53-0.74), and OS (HR 0.69, 95% CI: 0.61-0.78), compared with non-IOCT–treated patients. Sensitivity analyses also demonstrated the OS advantage of IOCT across different combination modalities, intervention agents, malignancy types, and PD-L1 expression (all P<0.05). Notably, there were higher odds of high-grade (grade≥3) adverse events with IOCT (RR: 1.81, 95% CI: 1.13-2.90), but the risk of treatment-related death (RR: 1.16, 95% CI: 0.84–1.60) was not increased compared with non-IOCT. Conclusions. IOCT is a preferable treatment option over PD-1/PD-L1 inhibitor monotherapy and conventional therapy for patients with advanced solid tumors. However, we should note the increased incidence rate of high-grade AEs in IOCT. more...

Background: Ferroptosis is a newly discovered type of cell death that is closely related to cancer, however, the characteristics of ferroptosis and its regulators in cancers are still largely unknown. Methods: Based on the cancer omics data in The Cancer Genome Atlas, we comprehensively analyzed the alterations of ferroptosis regulator genes (FRGs) and computationally established the ferroptosis potential index (FPI) to reveal the functional roles of ferroptosis in cancer. Findings: We found that the mutation rates of FRGs were generally low, but most FRGs were differentially expressed in tumors among various cancer types. Frequent copy number alterations (CNA) and differential DNA methylation of FRGs contributed greatly to their aberrant expression. In most cancers, the FPI was higher in tumors than in the adjacent normal tissues and was associated with histological/molecular subtypes and clinical features. We observed that the FPI was negatively correlated with a number of metabolism pathways such as terpenoid backbone biosynthesis, but positively associated with metastasis-related pathways such as epithelial-mesenchymal transition (EMT), WNT beta-catenin signaling and angiogenesis. The FPI was also correlated immune microenvironment since it was positively correlated with pathways such as IL6 JAK-STAT signaling, inflammatory response, complement. Furthermore, it was observed that high FPI predicted significantly worse overall survival in glioblastoma multiforme, renal clear/papillary cell carcinoma, hepatocellular carcinoma, and lung adenocarcinoma, while FPI and FRGs were intensively correlated with cancer drug sensitivity. Interpretation: Our study presents a systematical analysis of ferroptosis and its regulatory genes across cancers, and highlights the potential of ferroptosis-based cancer therapy. Funding Statement: This work was supported by grants from National Key RD and Science and Technology Program of Guangdong (2019B020227002 to RH.X.). Declaration of Interests: The authors declare that they have no competing interests. Ethics Approval Statement: Not required. more...

The present study aims to report the surgical outcome and long-term survival of conversion surgery and clarify its role in advanced gastric cancer. A total of 95 primary advanced gastric adenocarcinoma patients who underwent systemic chemotherapy and conversion surgery were reviewed retrospectively. The survival of conversion surgery was analyzed by Cox regression and the Kaplan–Meier method. Surgical outcomes were analyzed according to the Clavien–Dindo classification. The median survival time (MST) of the 95 patients was 26.8 months, and the postoperative MST was 19.3 months. The MSTs of the patients in categories 1, 2, 3, and 4 were 28.8, 25.5, 43.6, and 11.3 months, respectively. The MSTs of the patients who underwent R0 resection (47 cases) and R1/2 resection (48 cases) were 49.3 months and 21.9 months, respectively. The MST of patients treated with total gastrectomy was shorter (21.9 months) than that of patients who underwent proximal (55.0 months) or distal (46.3 months) gastrectomy. Patients who received more than 6 cycles of induction chemotherapy had a longer MST than patients who received 3–5 cycles or 1–2 cycles (MST: 55.0 months versus 21.1 months versus 21.7 months). The incident postoperative complications and postoperative mortality rates were 10.5% and 1.1%, respectively. Advanced gastric cancer patients may obtain a survival benefit from conversion surgery, except category 4. Performing a sufficient number of cycles of induction chemotherapy (usually ≥ 6 cycles) is recommended. Surgical oncologists should perform R0 resection and avoid total gastrectomy. more...

SummaryFerroptosis is a type of cell death that related to cancer, however, the characteristics of ferroptosis in cancers are still uncertain. Based on the data in The Cancer Genome Atlas, we found that most ferroptosis regulator genes (FRGs) were differentially expressed in tumors, copy number alterations (CNA) and DNA methylation contributed to their aberrant expression. We established the ferroptosis potential index (FPI) to reveal the functional roles of ferroptosis and noticed that the FPI was higher in tumors than in normal tissues in most cancers, and was associated with subtypes and clinical features. The FPI was negatively correlated with several metabolism pathways but positively associated with several important metastasis-related pathways and immune-related pathways. Higher FPI predicted worse prognosis in several tumors, while FPI and FRGs impacted drug sensitivity. Our study presents a systematical analysis of ferroptosis and its regulatory genes, and highlights the potential of ferroptosis-based cancer therapy. more...

Objective Conversion surgery is a surgery with a purpose of R0 resection in primary advanced gastric cancer (GC) that responded well to systemic chemotherapy. This study aimed to explore the efficacy of conversion surgery for advanced GC. Methods A total of 618 advanced GC patients receiving systemic chemotherapy were stratified into low-, moderate- and high-risk groups based on a nomogram-predicted probability of overall survival. The survival of conversion surgery and chemotherapy alone groups was compared using the log-rank test and Cox regression analysis after propensity score matching (PSM). Results A nomogram with good discrimination (concordance index: 0.65) and accurate calibration was constructed. After PSM, the median survival time (MST) of conversion surgery was 26.80 months, compared with 16.60 months of chemotherapy alone (P more...

e16004 Background: Mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H) serves as a predictor poor response to adjuvant chemotherapy in stage II colon cancer patients. Our objective was to investigate the efficacy of adjuvant chemotherapy in dMMR/MSI-H gastric cancer (GC). Methods: We searched literatures through December, 2020 to identify clinical studies that reported survival comparing adjuvant chemotherapy with surgery alone in dMMR/MSI-H GCs. Two approaches were used to pool the hazard ratio (HR) of survival: (1) If Kaplan-Meier curves and number at risk were provided, individual patient data were extracted. Cox models were used to calculate the HR with 95% confidence interval (CI); (2) for study-level data, pooled HR was estimated using fixed/random-effects models. Results: Six clinical studies were identified. For dMMR/MSI-H versus mismatch repair proficient (pMMR)/microsatellite stable (MSS)/microsatellite instability-low (MSI-L), the estimated 5-years DFS were 74.2% versus 51.5% (HR, 0.44; 95% CI, 0.32-0.62; P < 0.001); the estimated 5-years OS were 60.8% versus 50.1% (HR, 0.72; 95% CI, 0.60-0.88; P = 0.001). At study-level data, the pooled HRs were 0.42 for DFS (95% CI, 0.31-0.57; P < 0.001) and 0.66 for OS (95% CI, 0.32-1.38; P = 0.268). For adjuvant chemotherapy versus observation in dMMR/MSI-H, the estimated 5-years DFS were 76.1% versus 73.3% (HR, 0.72; 95% CI, 0.45-1.15; P = 0.171); the estimated 5-years OS were 74.9% versus 60.2% (HR, 0.60; 95% CI, 0.44-0.83; P = 0.001). Significant survival differences were also observed at study-level. Conclusions: This study further suggested adjuvant chemotherapy could be beneficial even in dMMR/MSI-H GC patients. more...