Immunohistochemical characteristics and potential therapeutic regimens of hepatoid adenocarcinoma of the stomach: a study of 139 cases

Hepatoid adenocarcinoma of stomach (HAS) is a special subtype of gastric cancer with poor prognosis. Immunohistochemical analysis could provide important clues for the treatment of HAS. A total of 159 patients were diagnosed as HAS and 139 were enrolled in this study. Statistical differences were determined using relative test methods and survival analyses were performed by the Kaplan-Meier method to find survival differences. All tumors in this study were negative for Epstein-Barr virus-encoded small RNAs (EBERs) and almost all showed no loss of mismatch repair (MMR) proteins and were positive for alpha fetoprotein (AFP or spalt like transcription factor 4 (SALL4). About half of the tumors had a positive programmed death-ligand 1 combined positive score (CPS) and 17.3% were positive for human epidermal growth factor receptor 2 (HER2). In addition, there was a relatively high proportion of cmet expression. We also found that HAS patients with recurrent disease treated by emerging therapy had a better survival than those treated with traditional chemotherapy (p = 0.002, median recurrence-to-death survival: 23 months versus 6 months); HAS patients who received anti-HER2 therapy or harbored MMR deficiency had favorable prognosis. Overall, high proportions of MMR protein proficiency, positivity for AFP or SALL4, overexpression of HER2, CPS and cmet, as well as negative EBER findings, are distinctive characteristics of HAS patients. While negative EBER and MMR proficiency indicate molecular features of HAS, positivity for AFP or SALL4 could aid in the diagnosis of HAS. In addition, HAS patients could benefit from anti-HER2 therapy, immunotherapy, and anti-angiogenesis therapy.

Double-tract reconstruction is superior to esophagogastrostomy in controlling reflux esophagitis and enhancing quality of life after proximal gastrectomy: Results from a prospective randomized controlled clinical trial in China

Objective

The aim of this study was to prospectively compare double-tract reconstruction (DTR) and esophagogastrostomy (EG) after proximal gastrectomy (PG) regarding the incidence of reflux esophagitis, quality of life (QOL), nutritional status and surgical safety.

Methods

This study was a randomized controlled trial. Patients eligible for PG were enrolled and randomly assigned to the EG group and DTR group. The characteristics of patients, parameters for surgical safety, incidence of reflux esophagitis, nutrition status and QOL were collected and compared between the two groups. Univariate analysis and multivariate analysis were performed to determine the significant factors affecting the incidence of reflux esophagitis after PG.

Results

Thirty-seven patients of the EG group and 36 patients of the DTR group were enrolled. The incidence of reflux esophagitis was significantly lower in the DTR group than in the EG group (8.3% vs. 32.4%, P=0.019). The DTR group demonstrated a more favorable QOL than the EG group after PG. The nutritional status was balanced within the EG group and the DTR group. The operation time was longer in the DTR group than in the EG group (191 min vs. 221 min, P=0.001), while surgical safety was similar in the two groups.

Conclusions

Our research demonstrated that DTR is superior to EG after PG in terms of the incidence of reflux esophagitis and provides a more satisfactory QOL without increasing surgical complications or sacrificing nutritional status.

Exploration of molecular markers related to chemotherapy efficacy of hepatoid adenocarcinoma of the stomach

PURPOSE

Preoperative neoadjuvant chemotherapy may not improve the prognosis of patients with hepatoid adenocarcinoma of the stomach (HAS), a rare pathological type of gastric cancer. Thus, the study aimed at the genomic and transcriptomic impacts of preoperative chemotherapy on HAS.

METHODS

Patients with HAS who underwent surgical resection at Peking University Cancer Hospital were retrospectively included in this study. Whole exome sequencing and transcriptome sequencing were performed on pre-chemotherapy, non-chemotherapy and post-chemotherapy samples. We then compared the alterations in molecular markers between the post-chemotherapy and non-chemotherapy groups, and between the chemotherapy-effective and chemotherapy-ineffective groups, respectively.

RESULTS

A total of 79 tumor samples from 72 patients were collected. Compared to the non-chemotherapy group, the mutation frequencies of several genes were changed after chemotherapy, including TP53. In addition, there was a significant increase in the frequency of frameshift mutations and cytosine transversion to adenine (C > A), appearance of COSMIC signature 6 and 14, and a reduced gene copy number amplification. Interestingly, the same phenomenon was observed in chemotherapy-ineffective patients. In addition, many HAS patients had ERBB2, FGFR2, MET and HGF gene amplification. Moreover, the expression of immune-related genes, especially those related to lymphocyte activation, was down-regulated after chemotherapy.

CONCLUSION

Chemotherapy is closely associated with changes in the molecular characteristics of HAS. After chemotherapy, at genomic and transcriptome level, many features were altered. These changes may be molecular markers of poor chemotherapeutic efficacy and play an important role in chemoresistance in HAS. In addition, ERBB2, FGFR2, MET and HGF gene amplification may be potential therapeutic targets for HAS.

Liquid biopsy: circulating tumor DNA monitors neoadjuvant chemotherapy response and prognosis in stage II/III gastric cancer

A good response to neoadjuvant chemotherapy (NACT) is strongly associated with a higher curative resection rate and favorable outcomes for patients with gastric cancer (GC). We examined the utility of serial circulating tumor DNA (ctDNA) testing for monitoring NACT response and prognosis in stage II-III GC. Seventy-nine patients were enrolled to receive two cycles of NACT following gastrectomy with D2-lymphadenectomy. Plasma at baseline, post-NACT, and after surgery, and tissue at pretreatment and surgery were collected. We used a 425-gene panel to detect genomic alterations (GAs). Results show that the mean cell-free DNA concentration of patients with clinical stage III was significantly higher than patients with stage II (15.43 ng·mL-1 vs 14.40 ng·mL-1 ). After receiving NACT and surgery, the overall detection rate of ctDNA gradually reduced (59.5%, 50.8%, and 47.4% for baseline, post-NACT, and postsurgery). The maximum variant allele frequency (max-VAF) and the number of GAs decreased from 0.50% to 0.08% and from 2.9 to 1.7 after NACT. For patients with a partial response after NACT, the max-VAF and the number of GAs declined significantly, but they increased for patients with progressive disease. Patients with detectable ctDNA at baseline, after NACT, or after surgery have a worse overall survival (OS) than patients with undetectable ctDNA. The estimated 3-year OS was 73% for the post-NACT ctDNA-negative patients and 34% for ctDNA-positive. Patients with perpetual negative ctDNA before and after NACT have the best prognosis. In conclusion, ctDNA was proposed as a potential biomarker to predict prognosis and monitor the NACT response for stage II-III GC patients.

CEDAR: communication efficient distributed analysis for regressions

Electronic health records (EHRs) offer great promises for advancing precision medicine and, at the same time, present significant analytical challenges. Particularly, it is often the case that patient-level data in EHRs cannot be shared across institutions (data sources) due to government regulations and/or institutional policies. As a result, there are growing interests about distributed learning over multiple EHRs databases without sharing patient-level data. To tackle such challenges, we propose a novel communication efficient method that aggregates the optimal estimates of external sites, by turning the problem into a missing data problem. In addition, we propose incorporating posterior samples of remote sites, which can provide partial information on the missing quantities and improve efficiency of parameter estimates while having the differential privacy property and thus reducing the risk of information leaking. The proposed approach, without sharing the raw patient level data, allows for proper statistical inference. We provide theoretical investigation for the asymptotic properties of the proposed method for statistical inference as well as differential privacy, and evaluate its performance in simulations and real data analyses in comparison with several recently developed methods.

Research progress of minimally invasive surgery for gastric cancer

Since the first laparoscopic radical surgery for early gastric cancer 30 years ago, there has been a gradual shift from "open" to "minimally invasive" surgery for gastric cancer. This transition is due to advancements in refined anatomy, enlarged field of view, faster recovery, and comparable oncological outcomes. Several high-quality clinical studies have demonstrated the safety and effectiveness of laparoscopy in the treatment of both early and locally advanced gastric cancer. The role of perioperative chemotherapy in managing locally advanced gastric cancer has been widely recognized, and there have been continuous breakthroughs in the exploration of targeted therapy and immunotherapy for perioperative treatment. Additionally, the application of indocyanine green near-infrared imaging technology, 3D laparoscopic technology, and robotic surgery systems has further improved the accuracy and minimally invasive nature of gastric cancer surgeries. Looking ahead, the field of minimally invasive surgery for gastric cancer is expected to become more standardized, resulting in a significant enhancement in the quality of life for gastric cancer patients.

Spatially resolved multi-omics highlights cell-specific metabolic remodeling and interactions in gastric cancer

Mapping tumor metabolic remodeling and their spatial crosstalk with surrounding non-tumor cells can fundamentally improve our understanding of tumor biology, facilitates the designing of advanced therapeutic strategies. Here, we present an integration of mass spectrometry imaging-based spatial metabolomics and lipidomics with microarray-based spatial transcriptomics to hierarchically visualize the intratumor metabolic heterogeneity and cell metabolic interactions in same gastric cancer sample. Tumor-associated metabolic reprogramming is imaged at metabolic-transcriptional levels, and maker metabolites, lipids, genes are connected in metabolic pathways and colocalized in the heterogeneous cancer tissues. Integrated data from spatial multi-omics approaches coherently identify cell types and distributions within the complex tumor microenvironment, and an immune cell-dominated "tumor-normal interface" region where tumor cells contact adjacent tissues are characterized with distinct transcriptional signatures and significant immunometabolic alterations. Our approach for mapping tissue molecular architecture provides highly integrated picture of intratumor heterogeneity, and transform the understanding of cancer metabolism at systemic level.

Nab-paclitaxel combined with oxaliplatin and S-1 as conversion therapy for advanced gastric adenocarcinoma

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Background: Conversion therapy can improve the survival of patients with locally advanced unresectable or potentially resectable metastatic gastric adenocarcinoma. This study was conducted to evaluate the efficacy and safety of nab-paclitaxel combined with oxaliplatin and S-1 as a conversion therapy in gastric cancer. Methods: This was a single-arm, multicenter, open-label trial of patients with locally advanced unresectable or potentially resectable metastatic gastric adenocarcinoma. Eligible patients were administered nab-paclitaxel (150 mg/m2, day 1), oxaliplatin (85 mg/m2, day 1), and S-1 (80–120 mg/day, days 1–14) every 21 days for two or four cycles. Radiographic assessments were performed after two cycles of treatment. Subsequent treatment or surgery was decided by the investigator according to assessment results and patient's condition. The primary endpoint was R0 resection rate. Secondary endpoints included progression-free survival (PFS), overall survival (OS), and safety. Results: From January 2020 to September 2022, 62 patients (49 males/13 females) with a median age of 58.9 years (range: 36–73) were enrolled in this study. Sixteen (25.8%) of the 62 patients had distant metastasis. The overall response rate and disease control rate of 54 patients who underwent at least one assessment were 61.1% (33/54, 95% CI: 46.9–74.1%) and 94.4% (51/54, 95% CI: 84.6–98.8%), respectively. Of the 39 patients who underwent surgery, 33 (84.6%, 95% CI: 69.5–94.1%) patients had an R0 resection, two had an R1 resection, and four had exploratory laparotomies. The pathological complete response rate was 15.4% (6/39, 95% CI: 6.4–31.2%). After a median follow-up time of 8.4 months, the 1-year PFS rate was 68.6% (95% CI: 53.4–83.8%), whereas the median PFS and OS were not reached. Seven patients died because of disease progression (5 patients who did not undergo surgery), myocardial infarction (1 patient), and electrolyte disturbance (1 patient). Treatment-related adverse events occurred in 82.3% (51/62) patients, although most events were grade 1–2. Common hematological toxicities were leukopenia (61.3%), neutropenia (54.8%), anemia (41.9%), and thrombocytopenia (30.6%). Common non-hematological treatment-related adverse events were nausea (53.2%), fatigue (43.5%), hepatic function abnormal (33.9%), neurotoxicity (29.0%), and diarrhea (24.2%). Conclusions: Nab-paclitaxel combined with oxaliplatin and S-1 showed promising efficacy and acceptable toxicity in patients with locally advanced unresectable or potentially resectable metastatic gastric cancer. Clinical trial information: NCT04047953 .

Prognostic impact of sarcopenia in patients with locally advanced adenocarcinoma of the esophagogastric junction treated with neoadjuvant chemoradiotherapy

Background

Few studies have evaluated the significance of sarcopenia in predicting the outcomes of patients with adenocarcinoma of the esophagogastric junction (AEG), especially those who received neoadjuvant chemoradiotherapy (NCRT). We aimed to identify the sarcopenic status and its impact on the outcomes of patients with locally advanced AEG who received NCRT followed by radical surgery or systemic therapy.

Materials and methods

Patients with T3-4N+M0 AEG with accessible abdominal computed tomography (CT) before and after NCRT were retrospectively analyzed. Body composition parameters, particularly the skeletal muscle index (SMI), were assessed using a CT-based method, and sarcopenia was defined using a predetermined SMI cutoff value. Survival analysis was conducted using the Kaplan-Meier method. A Cox proportional hazards regression model was used to identify independent prognostic factors. Receiver operating characteristic curve analysis was carried out, and the area under the curve (AUC) was calculated to test the prognostic accuracy of different factors.

Results

A total of 63 patients were enrolled, 65.1 and 79.4% of whom developed pre- and post-NCRT sarcopenia, respectively. Patients with pre-NCRT sarcopenia had lower radical surgery rates (70.7 vs. 95.5%, p = 0.047) than those without sarcopenia; however, sarcopenic status did not affect other short-term outcomes, including treatment-related toxicity and efficacy. Pre-NCRT sarcopenia was identified as an independent predictive factor for poor overall survival (OS) [adjusted hazard ratio (HR), 6.053; p = 0.002] and progression-free survival (PFS) (adjusted HR, 2.873; p = 0.031). Compared with nutritional indices such as the Nutritional Risk Screening 2002, weight loss during NCRT, and post-NCRT sarcopenia, pre-NCRT sarcopenia was regarded as the best predictive index for the 5-year OS (AUC = 0.735) and PFS rates (AUC = 0.770).

Conclusion

Pre-NCRT sarcopenia may be an independent predictive factor for OS and PFS rates in patients with locally advanced AEG receiving multimodal treatment.

Prognostic significance of preoperative serum tumor markers in hepatoid adenocarcinoma of stomach (HAS)

BACKGROUND

The role of preoperative serum tumor markers in HAS patients was vague, we designed the study to explore the effect of preoperative serum tumor markers on predicting the prognosis of HAS patients.

METHODS

A total of 139 patients were included according to the different tumor makers. X-tile tool was employed to identify the optimal cut-off values of respective tumor makers. Multivariate analyses were conducted to determine independent risk factors.

RESULTS

The optimal cut-off value of alpha-fetoprotein (AFP) for 3-years overall survival (OS) and recurrence-free survival (RFS) was 516 ng/mL. Patients with high-level AFP values assumed significantly worse OS and RFS than those with low-level AFP values (P = 0.028 and P = 0.011, respectively). The optimal cut-off value of Carbohydrate antigen (CA)19-9 for OS and RFS was 51.3 U/mL. And the survival results were similar with AFP in the aspects of OS and RFS (P = 0.009 and P < 0.001, respectively). Multivariate analyses showed that high serum AFP was an independent risk factor for OS and RFS of HAS patients (HR7.264; 95% CI 1.328-39.738; P = 0.022 and HR 2.688; 95% CI 0.922-7.836; P = 0.070, respectively). CA19-9 could perform as a fair substitute to predict the HAS patients' OS and RFS when the preoperative serum AFP was unavailable (HR 7.816; 95% CI 2.084-29.308; P = 0.002 and HR 4.386; 95% CI 1.824-10.547; P = 0.001, respectively). Other tumor markers didn't present significant influences.

CONCLUSIONS

Applying preoperative serum AFP level to predict the HAS patients' prognosis is feasible and preoperative serum high-AFP is an independent risk factor for OS and RFS of HAS patients. Preoperative serum CA19-9 could be an alternative choice when AFP was absent.

Parallel single-cell and bulk transcriptome analyses reveal key features of the gastric tumor microenvironment

BACKGROUND

The tumor microenvironment (TME) has been shown to strongly influence treatment outcome for cancer patients in various indications and to influence the overall survival. However, the cells forming the TME in gastric cancer have not been extensively characterized.

RESULTS

We combine bulk and single-cell RNA sequencing from tumors and matched normal tissue of 24 treatment-naïve GC patients to better understand which cell types and transcriptional programs are associated with malignant transformation of the stomach. Clustering 96,623 cells of non-epithelial origin reveals 81 well-defined TME cell types. We find that activated fibroblasts and endothelial cells are most prominently overrepresented in tumors. Intercellular network reconstruction and survival analysis of an independent cohort imply the importance of these cell types together with immunosuppressive myeloid cell subsets and regulatory T cells in establishing an immunosuppressive microenvironment that correlates with worsened prognosis and lack of response in anti-PD1-treated patients. In contrast, we find a subset of IFNγ activated T cells and HLA-II expressing macrophages that are linked to treatment response and increased overall survival.

CONCLUSIONS

Our gastric cancer single-cell TME compendium together with the matched bulk transcriptome data provides a unique resource for the identification of new potential biomarkers for patient stratification. This study helps further to elucidate the mechanism of gastric cancer and provides insights for therapy.

Correlation between imaging features on computed tomography and combined positive score of PD-L1 expression in patients with gastric cancer

OBJECTIVE

To explore the correlation between computed tomography (CT) features and combined positive score (CPS) of programmed cell death ligand 1 (PD-L1) expression in patients with gastric cancer (GC).

METHODS

This study reviewed an institutional database of patients who underwent GC operation without neoadjuvant chemotherapy between December 2019 and September 2020. The CPS results of PD-L1 expression of postoperative histological examination were recorded by pathology. Baseline CT features were measured, and their correlation with CPS 5 or 10 score groups of PD-L1 expression was analyzed.

RESULTS

Data for 153 patients with GC were collected. Among them, 124 were advanced GC patients, and 29 were early GC patients. None of the CT features significantly differed between CPS groups with a cutoff score of 5 and a score of 10 in patients with early GC. In advanced GC, the presence of lymph nodes with short diameters >10 mm was significantly different (P=0.024) between the CPS<5 and CPS≥5 groups. CT features such as tumor attenuation in the arterial phase, long and short diameter of the largest lymph node, the sum of long diameter of the two largest lymph nodes, the sum of short diameter of the two largest lymph nodes, and the presence of lymph nodes with short diameters >10 mm significantly differed between the CPS<10 and CPS≥10 groups in advanced GC. The sensitivity, specificity and area under receiver operating characteristic (ROC) curve of logistic regression model for predicting CPS≥10 was 71.7%, 50.0% and 0.671, respectively. Microsatellite instability (MSI) status was significantly different in CPS groups with cutoff score of 5 and 10 in advanced GC patients.

CONCLUSIONS

CT findings of advanced GC patients with CPS≥10 showed greater arterial phase enhancement and larger lymph nodes. CT has the potential to help screen patients suitable for immunotherapy.

Characteristics of lymph node stations/basins metastasis and construction and validation of a preoperative combination prediction model that accurately excludes lymph node metastasis in early gastric cancer

OBJECTIVE

To explore the candidate indications for function-preserving curative gastrectomy and sentinel lymph node navigation surgery in early gastric cancer (EGC).

METHODS

The clinicopathological data of 561 patients with EGC who underwent radical gastrectomy for gastric cancer at Peking University Cancer Hospital from November 2010 to November 2020 with postoperative pathological stage pT1 and complete examination data, were collected. Pearson's Chi-square test was used and binary logistic regression was employed for univariate and multivariate analyses. Combined analysis of multiple risk and protective factors for lymph node metastasis (LNM) of EGC was performed. A negative predictive value (NPV) combination model was built and validated.

RESULTS

LNM occurred in 85 of 561 patients with EGC, and the LNM rate was 15.15%. NPV for LNM reached 100% based on three characteristics, including ulcer-free, moderately well differentiation and patient <65 years old or tumor located at the proximal 1/3 of the stomach. Regarding lymphatic basin metastasis, multivariate analysis showed that the metastatic proportion of the left gastric artery lymphatic basin was significantly higher in male patients compared with female patients (65.96% vs. 38.89%, P<0.05). The proportion of right gastroepiploic artery lymphatic basin metastasis in patients with a maximum tumor diameter >2 cm was significantly greater than that noted in patients with a maximum tumor diameter ≤2 cm (60.78% vs. 28.13%, P<0.05).

CONCLUSIONS

Characteristics of lymph node stations/basins metastasis will facilitate precise lymph node resection. The NPV for LNM reaches 100% based on the following two conditions: young and middle-aged EGC patients, well-differentiated tumors, and without ulcers; or well-differentiated tumors, without ulcers, and tumors located in the proximal stomach. These findings can be used as the recommended indications for function-preserving curative gastrectomy and sentinel lymph node navigation surgery.

Gender representation on editorial boards of leading oncology journals

Background

There has historically been women underrepresentation on editorial boards of peer-reviewed medical journals. High-ranked oncology journals showcase cancer-related scientific work at the forefront of the discipline. There is urgent need to investigate gender representation on editorial boards at leading oncology journals.

Materials and methods

Sixty high-ranked oncology journals based on impact factor calculated by the Journal Citation Reports (JCR) 2021 from Web of Science/Clarivate Analytics were identified. Gender-related information of editorial boards was obtained from each journal’s website. The gender of each member of the editorial team was confirmed by an internet search for picture and/or gender-specific pronoun from journal or personal profile. Fisher’s exact tests and analysis of variance were used to analyze categorical and continuous variables, respectively. Significance was set at P < 0.05.

Results

Among 4898 members on editorial boards of top oncology journals with the highest impact factor, 1177 were women. Women made up 24% (1177 of 4898) of members on editorial boards in top oncology journals, and there was significantly less women board members than men (P < 0.0001). The mean female composition of editorial boards of oncology journals was 27% (range from 4% to 100%). Among 71 editors-in-chief of the top oncology journals, 14 (20%) were women. There was a positive correlation between the presence of women in journal editorial leadership and the percentage of women on editorial boards (r_s = 0.340, P = 0.008). The underrepresentation of women on oncology journal editorial boards was significantly different among quartiles of journal impact factor. There was no significant correlation between women’s representation on journal editorial boards (%) and journal impact factors (r_s = 0.226, P = 0.086).

Conclusions

The results demonstrated that there are gender disparities among editorial leadership at high-impact oncology journals. There are cultural and structural barriers and prejudices to gender parity and diversity on editorial boards of oncology journals.

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The representation of women on editorial boards of oncology journals has not been verified.

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This large-scale study found that women comprised only 24% of editorial boards of top-ranked oncology journals.

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The results demonstrated that there are gender disparities among editorial leadership at leading oncology journals.

Immune phenotypic linkage between colorectal cancer and liver metastasis

The tumor microenvironment (TME) is connected to immunotherapy responses, but it remains unclear how cancer cells and host tissues differentially influence the immune composition within TME. Here, we performed single-cell analyses for autologous samples from liver metastasized colorectal cancer to disentangle factors shaping TME. By aligning CD45⁺ cells across different tissues, we classified exhausted CD8⁺ T cells (Texs) and activated regulatory T cells as M-type, whose phenotypes were associated with the malignancy, while natural killer and mucosal-associated invariant T cells were defined as N-type, whose phenotypes were associated with the niche. T cell receptor sharing between Texs in primary and metastatic tumors implicated the presence of common peripheral non-exhausted precursors. For myeloid cells, a subset of dendritic cells (DC3s) and SPP1⁺ macrophages were M-type, and the latter were predominant in liver metastasis, indicating its pro-metastasis role. Our analyses bridge immune phenotypes of primary and metastatic tumors, thereby helping to understand the tumor-specific contexture and identify the pro-metastasis components.

Establishment of prognostic models for adenocarcinoma of oesophagogastric junction patients with neoadjuvant chemoradiotherapy: a real-world study

Background

Multimodal therapies based on surgical resection have been recommended for the treatment of adenocarcinoma of the oesophagogastric junction (AEG). We aimed to evaluate prognostic factors in AEG patients receiving neoadjuvant chemoradiotherapy and to build predictive models.

Methods

T3 − T4N + M0 AEG patients with resectable Siewert type II/III tumours were enrolled in this study. All patients underwent neoadjuvant chemoradiation, followed by radical surgery or systemic therapy according to clinical response. Survival analysis was performed using the Kaplan–Meier method; multivariate analysis using the Cox proportional hazards method was also conducted. The Harrell concordance index (C-index) was used to test the prognostic value of models involving prognostic factors, and consistency between actual and predicted survival rates was evaluated by calibration curves.

Results

From February 2009 to February 2018, 79 patients were treated with neoadjuvant chemoradiotherapy; 60 patients of them underwent radical surgery. The R0 resection rate was 98.3%, and 46.7% of patients achieved a major pathologic response (MPR), namely, a residual tumour issue less than 10%. The 5-year overall survival (OS) rate was 63%, and the 5-year progression-free survival (PFS) rate was 48%. The incidence of grade 3 complications was 21.5%, and no grade 4 complications were reported. According to the results of univariate and multivariate analyses, we included the neutrophil–lymphocyte ratio (NLR), prognostic nutrition index (PNI), eosinophilic granulocyte (EOS) and postoperative pathologic stage in nomogram analysis to establish prediction models for OS and PFS; the C-index of each model was 0.814 and 0.722, respectively. Both the C-index and calibration curves generated to validate consistency between the actual and predicted survival indicated that the models were well calibrated and of good predictive value.

Conclusions

AEG patients achieved favourable downstaging and pathologic response after neoadjuvant chemoradiation, with acceptable adverse effects. Inflammation-based and nutrition-related factors and postoperative pathologic stage had a significant influence on OS and PFS, and the predictive value was verified through prognostic models.

The Value of Perioperative Chemotherapy for Patients With Hepatoid Adenocarcinoma of the Stomach Undergoing Radical Gastrectomy

BACKGROUND

Hepatoid adenocarcinoma of the stomach (HAS) is a rare type of gastric cancer, but the role of perioperative chemotherapy is still poorly understood. The aim of this retrospective study was to investigate the associations between perioperative chemotherapy and prognosis of HAS.

METHOD

We retrospectively analyzed patients with locally advanced HAS who received radical surgery in Peking University Cancer Hospital between November 2009 and October 2020. Patients were divided into neoadjuvant chemotherapy-first (NAC-first) group and surgery-first group. The relationships between perioperative chemotherapy and prognosis of HAS were analyzed using univariate, multivariate survival analyses and propensity score matching analysis (PSM).

RESULTS

A total of 100 patients were included for analysis, including 29 in the NAC-first group and 71 in the surgery-first group. The Her-2 amplification in HAS patients was 22.89% (19/83). For NAC-first group, 4 patients were diagnosed as tumor recession grade 1 (TRG1), 4 patients as TRG 2, and 19 patients as TRG 3. No significant difference in prognosis between the surgery-first group and the NAC-first group (P=0.108) was found using PSM analysis. In the surgery-first group, we found that the survival rate was better in group of ≥6 cycles of adjuvant chemotherapy than that of <6 cycles (P=0.013).

CONCLUSION

NAC based on platinum and fluorouracil may not improve the Overall survival (OS) and Disease-free survival time (DFS) of patients with locally advanced HAS. Patients who received ≥6 cycles of adjuvant chemotherapy had better survival. Therefore, the combination treatment of radical gastrectomy and sufficient adjuvant chemotherapy is recommended for patients with locally advanced HAS.

A Practical Nomogram for Predicting the Prognosis of Elderly Patients with Gastric Adenocarcinoma After Gastrectomy

Purpose

To establish a pragmatic prognostic nomogram for predicting the survival of elderly patients undergoing gastrectomy for gastric adenocarcinoma.

Patients and Methods

Data of elderly patients undergoing gastrectomy for gastric adenocarcinoma between 2004 and 2015 were obtained from the Surveillance, Epidemiology, and End Results database. Prognostic factors were identified by the Kaplan–Meier method and the Cox proportional hazards model. Based on these factors, we developed a nomogram to predict the overall survival (OS) and gastric cancer-specific survival (GCSS). Concordance index (C-index) and calibration curve are employed to assess the predictive accuracy of the model. Decision curve analysis (DCA) and receiver operating characteristic curve (ROC) analysis are applied to further appraise the clinical utility of the model.

Results

A total of 8401 cases were incorporated into this research. After univariate and multivariate analyses, nine prognostic factors of OS were identified, including age (P < 0.001), race (P < 0.001), marital status (P < 0.001), tumor site (P < 0.001), tumor size (P = 0.024), differentiation (P < 0.001), T stage (P < 0.001), N stage (P < 0.001), and M stage (P < 0.001); ten prognostic factors of GCSS were identified, including age (P < 0.001), race (P < 0.001), tumor site (P < 0.001), tumor size (P = 0.002), differentiation (P < 0.001), T stage (P < 0.001), N stage (P < 0.001), M stage (P < 0.001), radiotherapy (P < 0.001) and chemotherapy (P < 0.001). The C-index of the constructed nomogram for OS was 0.708 (95% CI: 0.701–0.715) while for GCSS was 0.745 (95% CI: 0.737–0.753). The calibration curves of the nomogram predictions and actual observations displayed good agreement for the 3- and 5-year OS and GCSS probabilities. The results of DCA and the area under the curve calculated by ROC analysis showed that the developed model was superior than TNM stage.

Conclusion

The nomogram we established could accurately predict the prognosis of individual elderly patients who underwent gastrectomy for gastric adenocarcinoma.

Pan-cancer single-cell landscape of tumor-infiltrating T cells

[Figure: see text].

ARHGAP11A Is a Prognostic Biomarker and Correlated With Immune Infiltrates in Gastric Cancer

Background: ARHGAP11A, belongs to RhoGAPs family, is vital for cell motility. However, the role of ARHGAP11A in gastric cancer is obscure. Methods: The expression level of ARHGAP11A was analyzed by Oncomine database. The correlation of ARHGAP11A expression with immune infiltrates and associated gene markers was clarified by Tumor IMmune Estimation Resource and Gene Expression Profiling Interactive Analysis database. The correlation between ARHGAP11A expression and the patient prognosis was identified by Kaplan-Meier plotter and PrognoScan. Genetic changes of ARHGAP11A were analyzed by cBioPortal. The protein-protein interaction network and gene functional enrichment analysis were constructed and performed by GeneMANIA and Metascape. Results: We found that the expression levels of ARHGAP11A were elevated in various cancers including gastric cancer when compared with normal tissues. High expression of ARHGAP11A was significantly correlated with a better prognosis in gastric cancer. We revealed that the expression of ARHGAP11A was negatively associated with infiltration levels of CD8+ T cells, CD4+ T cells, macrophages and dendritic cells. In addition, ARHGAP11A expression was significantly correlated with gene markers of these immune cells. Lastly, gene functional enrichment analysis indicated that ARHGAP11A involved in regulating lymphocyte activation, cell division, cell killing, myeloid leukocyte differentiation and leukocyte apoptosis. Conclusion: Our findings demonstrated that ARHGAP11A was a valuable prognostic biomarker in gastric cancer. Further work is needed to validate its role and underlying mechanisms in regulating immune infiltrates.

Long term immunity against Peste Des Petits Ruminants mediated by a recombinant Newcastle disease virus vaccine

Peste des Petits Ruminants (PPR) is a highly contagious and often fatal disease of sheep and goats. Conventional live vaccines have been successfully used in endemic countries however, there are not completely safe and not allowing differentiation between vaccinated and infected animals (DIVA). In this study, a recombinant Newcastle disease virus (NDV) expressing the hemagglutinin of PPRV (NDV-PPRVH) was evaluated on small ruminants by serology response in sheep and goats, experimental infection in goats and immunity duration in sheep. The NDV-PPRVH vaccine injected twice at 28 days' interval, provided full protection against challenge with a virulent PPR strain in the most sensitive species and induced significant neutralizing antibodies. Immunological response in goats was slightly higher than sheep and the vaccine injected at 10^8.0 50 % egg infective dose/mL allowed anti-PPRV antibodies that lasted at least 12 months as shown by antibody response monitoring in sheep. The NDV vector presented a limited replication in the host and vaccinated animals remained negative when tested by cELISA based on PPRV nucleoprotein allowing DIVA. This recombinant vaccine appears to be a promising candidate in a free at risk countries and may be an important component of the global strategy for PPR eradication.

Perioperative or postoperative adjuvant oxaliplatin with S-1 versus adjuvant oxaliplatin with capecitabine in patients with locally advanced gastric or gastro-oesophageal junction adenocarcinoma undergoing D2 gastrectomy (RESOLVE): an open-label, superiority and non-inferiority, phase 3 randomised controlled trial

BACKGROUND

The optimal perioperative chemotherapeutic regimen for locally advanced gastric cancer remains undefined. We evaluated the efficacy and safety of perioperative and postoperative S-1 and oxaliplatin (SOX) compared with postoperative capecitabine and oxaliplatin (CapOx) in patients with locally advanced gastric cancer undergoing D2 gastrectomy.

METHODS

We did this open-label, phase 3, superiority and non-inferiority, randomised trial at 27 hospitals in China. We recruited antitumour treatment-naive patients aged 18 years or older with historically confirmed cT4a N+ M0 or cT4b Nany M0 gastric or gastro-oesophageal junction adenocarcinoma, with Karnofsky performance score of 70 or more. Patients undergoing D2 gastrectomy were randomly assigned (1:1:1) via an interactive web response system, stratified by participating centres and Lauren classification, to receive adjuvant CapOx (eight postoperative cycles of intravenous oxaliplatin 130 mg/m² on day one of each 21 day cycle plus oral capecitabine 1000 mg/m² twice a day), adjuvant SOX (eight postoperative cycles of intravenous oxaliplatin 130 mg/m² on day one of each 21 day cycle plus oral S-1 40-60 mg twice a day), or perioperative SOX (intravenous oxaliplatin 130 mg/m² on day one of each 21 day plus oral S-1 40-60 mg twice a day for three cycles preoperatively and five cycles postoperatively followed by three cycles of S-1 monotherapy). The primary endpoint, assessed in the modified intention-to-treat population, 3-year disease-free survival to assess the superiority of perioperative-SOX compared with adjuvant-SOX and the non-inferiority (hazard ratio non-inferiority margin of 1·33) of adjuvant-SOX compared with adjuvant-CapOx. Safety analysis were done in patients who received at least one dose of the assigned treatment. This study is registered with ClinicalTrials.gov, NCT01534546.

FINDINGS

Between Aug 15, 2012, and Feb 28, 2017, 1094 patients were screened and 1022 (93%) were included in the modified intention-to-treat population, of whom 345 (34%) patients were assigned to the adjuvant-CapOx, 340 (33%) patients to the adjuvant-SOX group, and 337 (33%) patients to the perioperative-SOX group. 3-year disease-free survival was 51·1% (95% CI 45·5-56·3) in the adjuvant-CapOx group, 56·5% (51·0-61·7) in the adjuvant-SOX group, and 59·4% (53·8-64·6) in the perioperative-SOX group. The hazard ratio (HR) was 0·77 (95% CI 0·61-0·97; Wald p=0·028) for the perioperative-SOX group compared with the adjuvant-CapOx group and 0·86 (0·68-1·07; Wald p=0·17) for the adjuvant-SOX group compared with the adjuvant-CapOx group. The most common grade 3-4 adverse events was neutropenia (32 [12%] of 258 patients in the adjuvant-CapOx group, 21 [8%] of 249 patients in the adjuvant-SOX group, and 30 [10%] of 310 patients in the perioperative-SOX group). Serious adverse events were reported in seven (3%) of 258 patients in adjuvant-CapOx group, two of which were related to treatment; eight (3%) of 249 patients in adjuvant-SOX group, two of which were related to treatment; and seven (2%) of 310 patients in perioperative-SOX group, four of which were related to treatment. No treatment-related deaths were reported.

INTERPRETATION

Perioperative-SOX showed a clinically meaningful improvement compared with adjuvant-CapOx in patients with locally advanced gastric cancer who had D2 gastrectomy; adjuvant-SOX was non-inferior to adjuvant-CapOx in these patients. Perioperative-SOX could be considered a new treatment option for patients with locally advanced gastric cancer.

FUNDING

National Key Research and Development Program of China, Beijing Scholars Program 2018-2024, Peking University Clinical Scientist Program, Taiho, Sanofi-Aventis, and Hengrui Pharmaceutical.

TRANSLATION

For the Chinese translation of the abstract see Supplementary Materials section.

Patient-derived tumor-like cell clusters for drug testing in cancer therapy

Several patient-derived tumor models emerged recently as robust preclinical drug-testing platforms. However, their potential to guide clinical therapy remained unclear. Here, we report a model called patient-derived tumor-like cell clusters (PTCs). PTCs result from the self-assembly and proliferation of primary epithelial, fibroblast, and immune cells, which structurally and functionally recapitulate original tumors. PTCs enabled us to accomplish personalized drug testing within 2 weeks after obtaining the tumor samples. The defined culture conditions and drug concentrations in the PTC model facilitate its clinical application in precision oncology. PTC tests of 59 patients with gastric, colorectal, or breast cancers revealed an overall accuracy of 93% in predicting their clinical outcomes. We implemented PTC to guide chemotherapy selection for a patient with mucinous rectal adenocarcinoma who experienced recurrence with metastases after conventional therapy. After three cycles of a nonconventional therapy identified by the PTC, the patient showed a positive response. These findings need to be validated in larger clinical trials, but they suggest that the PTC model could be prospectively implemented in clinical decision-making for therapy selection.

Construction and Validation of a Risk-Scoring Model that Preoperatively Predicts Lymph Node Metastasis in Early Gastric Cancer Patients

OBJECTIVE

The aim of this study was to create a risk-scoring model to preoperatively predict the incidence of lymph node metastasis (LNM) in early gastric cancer (EGC) patients to guide treatment.

METHODS

To construct the risk-scoring model, we retrospectively analyzed a primary cohort of 548 EGC patients. Univariate analysis and logistic regression were performed. A risk-scoring model for predicting LNM in EGC patients was developed based on preoperative factors, and another cohort of 73 patients was then analyzed to validate the model.

RESULTS

In the primary cohort, LNM was pathologically confirmed in 72 (13.1%) patients. In the multivariate analysis, the presence of ulceration and tumor size on gastroscopy, undifferentiated histological type, and presence of enlarged lymph nodes on computed tomography or endoscopic ultrasonography were independent risk factors for LNM. A 17-point risk-scoring model was developed to predict LNM risk. The cut-off score of the model was 8, and the area under the receiver operating characteristic curve (AUC) of the model was 0.835 [95% confidence interval (CI) 0.784-0.886]. In the validation cohort, the AUC of the model was 0.829 (95% CI 0.699-0.959).

CONCLUSIONS

We developed and validated an effective 17-point risk-scoring model that could preoperatively predict LNM for EGC patients.

Phase II trial of prophylactic hyperthermic intraperitoneal chemotherapy in patients with locally advanced gastric cancer after curative surgery

Background

HIPEC is an emerging procedure to treat peritoneal metastasis of gastric cancer. Data about HIPEC in locally advanced gastric cancer is scarce. The purpose of this trial is to evaluate the safety and toxicity of prophylactic HIPEC with cisplatin for patients with locally advanced gastric cancer.

Methods

From March 2015 to November 2016, a prospective, randomized phase II trial was conducted. After radical gastrectomy, patients in the experimental group underwent HIPEC with cisplatin followed by adjuvant chemotherapy with SOX regime. Patients in the other group were treated with SOX regime alone. Postoperative complications and patient survival were compared.

Results

In total, 50 patients were eligible for analyses. No significant difference was found in the incidence of postoperative complications including anastomotic/intestinal leakage, liver dysfunction, bone marrow suppression, wound infection and ileus (P > 0.05). Mean duration of hospitalization after radical gastrectomy was 11.7 days. 12.2 days in experimental group and 10.8 days in control group respectively (P = 0.255). The percentage of patients with elevated tumor markers was 12.1% in experimental group, which was significantly lower than 41.2% in control group (P = 0.02). 3-year RFS of patients who treated with or without prophylactic HIPEC were 84.8 and 88.2% respectively (P = 0.986). In the multivariate analysis, pathological T stage was the only independent risk factor for the RFS of patients (P = 0.012, HR =15.071).

Conclusion

Additional intraoperative HIPEC with cisplatin did not increase postoperative complications for locally advanced gastric cancer after curative surgery. Prophylactic HIPEC with cisplatin was safe and tolerable, while it did not reduce the risk of peritoneal recurrence in this trial, supporting further studies to validate the efficacy of it.

Trial registration

Chinese Clinical Trial Registry, ChiCTR2000038331. Registered 18 September 2020 - Retrospectively registered, http://www.chictr.org.cn/showproj.aspx?proj=59692.

Up-Regulation of SALL4 Is Associated With Survival and Progression via Putative WNT Pathway in Gastric Cancer

SALL4, a transcriptional factor involved in embryonic stem cell self-renewal and pluripotency, is overexpressed in gastric cancer (GC). However, the association of SALL4 with the survival of GC patients is not well-understood, and the role of SALL4 in cancer progression is still unknown. In the present study, a total of 1,815 GC patients who underwent radical resection at Peking Cancer Hospital were included consecutively from 2015 to 2018, confirming the prognostic value of SALL4 and validating by data from TCGA and GEO. The protein and mRNA expression levels of SALL4 were evaluated by immunohistochemistry and qPCR, respectively. Besides, GSEA and WGCNA were applied to explore the SALL4-related cancer-promoting signaling pathways and gene modules. Our results showed that overexpression of SALL4 was observed in 16.7% of GC patients. SALL4 positivity was associated with male, older age, mixed-type histology, late stages, lymphatic metastasis, vascular invasion, non-cardia location, high AFP level, and no EBV infection background. SALL4 could be served as a marker for prognostic prediction in GC, and SALL4-positive GC was significantly associated with shortened survival. Further, the bioinformatic analysis indicated that the Wnt/β-catenin signaling pathway was activated in SALL4-high cases compared with SALL4-low cases. Expression of SALL4 was also positively correlated with the expression of multiple co-expressed genes, such as TRIB3, which plays an important role in activating the Wnt/β-catenin pathway. Our findings indicate that SALL4 is associated with clinicopathological features related to cancer progression in GC and its function in the Wnt/β-catenin pathway.

A pan-cancer single-cell transcriptional atlas of tumor infiltrating myeloid cells

Tumor-infiltrating myeloid cells (TIMs) are key regulators in tumor progression, but the similarity and distinction of their fundamental properties across different tumors remain elusive. Here, by performing a pan-cancer analysis of single myeloid cells from 210 patients across 15 human cancer types, we identified distinct features of TIMs across cancer types. Mast cells in nasopharyngeal cancer were found to be associated with better prognosis and exhibited an anti-tumor phenotype with a high ratio of TNF+/VEGFA+ cells. Systematic comparison between cDC1- and cDC2-derived LAMP3+ cDCs revealed their differences in transcription factors and external stimulus. Additionally, pro-angiogenic tumor-associated macrophages (TAMs) were characterized with diverse markers across different cancer types, and the composition of TIMs appeared to be associated with certain features of somatic mutations and gene expressions. Our results provide a systematic view of the highly heterogeneous TIMs and suggest future avenues for rational, targeted immunotherapies.

A phase I study to evaluate the safety of multiantigen stimulated tumor specific cell therapy (MASCT-I) in subjects with advanced gastric cancer

200

Background: Gastric cancer was the fifth cancer world wide and the third leading cause of cancer-related death. PD-1 antibody has been approved for treatment in gastric cancer patients with positive expression of PD-L1 and microsatellite instability. MASCT-I (Multi-Antigen Stimulated Cell Therapy-I Injection) is an autologous non-engineered immune cell therapy for solid tumor, it is composed of multiple-antigen peptides(15 tumor associated antigens) loaded mature dendritic cells (DCs) and in vitro DC stimulated and proliferated effector T cells, the combination of MASCT-I and PD1 antibody could have a synergistic anti-tumor effect. Methods: This is a single center, phase I trial to explore the safety and tolerance of the combination of MASCT-I and PD-1 antibody in advanced gastric cancer (NCT03393416). 15 patients with PD-L1 expression or microsatellite instability were enrolled between April 2018, and June 2019. Camrelizumab was administered once every two weeks, DC and T cells were sequential administered once a month. Therapy continued until the disease progresses. Results: Only adverse reaction below grade 2 was observed related to MASCT-I,such as fever, fatigue etc. Abnormal liver function and reactive capillary hyperplasia may be related to Camrelizumab. Among the 15 patients, the longest treatment duration was 18.9 months, and the median progression-free survival (mPFS) was 3.93 months, among which, mPFS of patients with microsatellite instability is 10.23 months, mPFS of patients expressing PD-L1 is 2.35 months, which is slightly higher than the historical data of Camrelizumab alone in the treatment of advanced gastric cancer (8 weeks for mPFS). The patient 1002 always had high content of CD8+ cells and NK cells and the positive immune response in their bodies, which may plays a role in killing the tumor cells. Conclusions: The combination of MASCT-I and Camrelizumab in the treatment of advanced gastric cancer or gastroesophageal junction cancer is a safe treatment regimen, and its efficacy deserves further study. Clinical trial information: NCT03393416.

Effect of Additional Trastuzumab in Neoadjuvant and Adjuvant Treatment for Patients with Resectable HER2-Positive Gastric Cancer

BACKGROUND

Recent studies have reported a beneficial role of trastuzumab in neoadjuvant treatment (NAT) among resectable gastric cancer (GC) patients; however, the effect of adjuvant treatment (AT) combined with trastuzumab is understudied. We performed a retrospective cohort study to compare chemotherapies with or without trastuzumab among human epidermal growth factor receptor 2-positive (HER2 +) locally advanced GC patients in the AT and NAT settings, respectively.

METHODS

We enrolled 208 HER2 + resected GC patients who underwent perioperative/postoperative treatment in 2010-2019 in a single-centered hospital, including 135 AT patients and 73 NAT patients. We used inverse probability of treatment weighting (IPTW) to balance potential confounding factors between the treatment groups, and estimated the treatment effect of trastuzumab. Pathological and survival outcomes were evaluated.

RESULTS

The number of trastuzumab-exposed patients in the AT and NAT cohorts was 31 (23.0%) and 34 (46.6%), respectively. After IPTW adjustment, AT combined with trastuzumab showed a better overall survival (OS) over chemotherapy alone (p = 0.023). In IPTW-adjusted NAT analysis, trastuzumab-exposed patients had an improvement in tumor pathological regression and downstaging, with lower tumor regression grade scores (p = 0.002), ypTNM stages (p < 0.001), ypN stages (p = 0.035), and ypT stages (p < 0.001). Loss of HER2 positivity following trastuzumab treatment was observed in NAT patients; however, we did not observe any significant effect of trastuzumab on OS (p = 0.126).

CONCLUSIONS

Given the improvement in tumor regression and downstaging among NAT patients, and the OS benefit in AT patients, trastuzumab could be considered a promising treatment for locally advanced HER2 + GC patients. In particular, re-evaluation of HER2 status should be considered following NAT combined with trastuzumab.

ASB16-AS1 up-regulated and phosphorylated TRIM37 to activate NF-κB pathway and promote proliferation, stemness, and cisplatin resistance of gastric cancer

BACKGROUND

Long non-coding RNA (lncRNA) ASB16 antisense RNA 1 (ASB16-AS1) is recognized as an oncogene in several cancer types, but its relation to GC is unknown. Tripartite motif containing 37 (TRIM37) has been proven to accelerate the development of gastric cancer (GC), whereas the molecular mechanism assisted ASB16-AS1 and TRIM37 in regulating GC progression remains unclear.

METHODS

Differentially expressed lncRNAs in GC samples were analyzed based on Gene Expression Omnibus (GEO) data. CCK-8 and colony formation assays were applied to determine the proliferative ability of GC cells. Stem cell-like phenotype of GC cells was assessed by sphere formation assay and flow cytometry analysis. Luciferase reporter assay, RNA immunoprecipitation (RIP), pulldown, and co-immunoprecipitation (Co-IP) were performed to verify the interplay of RNA molecules.

RESULTS

ASB16-AS1 was upregulated in GC samples according to GEO data and qRT-PCR analysis. ASB16-AS1 strengthened the proliferative ability and stem cell-like characteristics in GC cells. More importantly, ASB16-AS1 encouraged GC cell growth in vivo. Mechanistically, ASB16-AS1 strengthened TRIM37 expression by sequestering miR-3918 and miR-4676-3p. ASB16-AS1 activated NF-kappa B (NF-κB) pathway by cooperating with ATM serine/threonine kinase (ATM) to induce TRIM37 phosphorylation.

CONCLUSION

In summary, ASB16-AS1 exerted oncogenic functions in GC through modulating TRIM37 expression at both mRNA and protein levels.

Surgical treatment of gastric cancer: Current status and future directions

Surgery is the most important and effective method for the treatment of gastric cancer. Since the first gastrectomy in the early 19th century, surgical treatment of gastric cancer has undergone more than 100 years of development. With the increasing understanding of gastric cancer and the promotion of a series of clinical trials, the concept of gastric cancer surgery has evolved from the initial "bigger is better" to today's "standardized surgery" and is developing towards individualized surgery focusing on accurate resection and quality of life. This trend has had a tremendous impact on the development of surgical treatments, such as minimally invasive surgeries, function-preserving surgeries, and the optimal extent of lymph node dissection. Understanding the development and current status of gastric cancer surgery and exploring the remaining academic controversies are goals that every gastric surgeon should constantly pursue. However, how should gastric cancer surgery develop in the future? What opportunities and challenges will we encounter? In this review, we elaborate on the development and current status of gastric cancer surgery based on a series of clinical studies and discuss the controversy in the development of gastric cancer surgery.

Identification of lymph node metastasis by computed tomography in early gastric cancer

Objective

Lymph node status is critical when selecting treatment methods for patients with early gastric cancer (EGC). The aim of this study was to assess the diagnostic value of computed tomography (CT) for detection of lymph node metastasis (LNM) in patients with EGC.

Methods

We retrospectively analyzed patients who had pathologically confirmed EGC between November 2010 and January 2019. After 1:1 propensity score matching, 65 patients with LNM and 65 patients without LNM were retained for comparison. The long diameter (LD) and short diameter (SD) of all visualized lymph nodes in all stations were recorded. The diagnostic value of LNM was assessed with receiver operating characteristic analysis.

Results

Among 130 patients, we found a total of 558 lymph nodes on the CT images. Among the diagnostic indicators, the number, sum of LD and sum of SD of lymph nodes greater than 3 mm had better discrimination. The areas under the curve were all greater than 0.75. As for different regions, the optimal cutoff values of number, the sum of LD and sum of SD were determined as follows: overall, ≥4, 19.9 mm and 13.5 mm; left gastric artery basin, ≥3, 15.7 mm and 8.6 mm; right gastroepiploic artery basin, ≥2, 8.6 mm and 7.0 mm.

Conclusions

CT is valuable for diagnosing LNM in EGC patients. The number, sum of LD and sum of SD of lymph nodes greater than 3 mm are preferable indicators. Different regional lymph nodes have different optimal criteria for predicting LNM in ECG patients.

Double Tract Reconstruction Reduces Reflux Esophagitis and Improves Quality of Life after Radical Proximal Gastrectomy for Patients with Upper Gastric or Esophagogastric Adenocarcinoma

Purpose

The aim of the present study was to compare the difference between double tract reconstruction and esophagogastrostomy.

Materials and Methods

Patients who underwent radical proximal gastrectomy with esophagogastrostomy or double tract reconstruction were included in this study.

Results

Sixty-four patients were included in this study and divided into two groups according to reconstruction method. The two groups were well balanced in perioperative safety and 3-year overall survival (OS). The rates of postoperative reflux esophagitis in the double tract reconstruction group and esophagogastrostomy group were 8.0% and 30.8%, respectively (p=0.032). Patients in the double tract reconstruction group had a better global health status (p < 0.001) and emotional functioning (p < 0.001), and complained less about nausea and vomiting (p < 0.001), pain (p=0.039), insomnia (p=0.003), and appetite loss (p < 0.001) based on the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 questionnaire. Regarding the EORTC QLQ-STO22 questionnaire, patients in the double tract reconstruction group complained less about dysphagia (p=0.030), pain (p=0.008), reflux (p < 0.001), eating (p < 0.001), anxiety (p < 0.001), dry mouth (p=0.007), and taste (p=0.001). The multiple linear regression analysis showed that reconstruction method, postoperative complications, reflux esophagitis, and operation duration had a linear relationship with the global health status score.

Conclusion

Double tract reconstruction could better prevent reflux esophagitis and improve quality of life without scarifying perioperative safety or 3-year OS.

A decision analysis comparing three strategies for peritoneal lavage cytology testing in staging of gastric cancer in China

BACKGROUND

Positive peritoneal cytology (PCY) indicates metastasis (M1) in gastric cancer (GC) patients; both the American and Chinese guidelines recommend laparoscopic peritoneal lavage (LPL) for cytology. However, relatively high costs impair the widespread use of LPL in some resource-limited regions in China, and the cost-effectiveness of PCY testing remains unclear. Therefore, we performed a decision analysis to evaluate the cost-effectiveness of PCY testing by comparing the guideline-recommended intraoperative LPL, a newly proposed preoperative percutaneous peritoneal lavage (PPL), and a third strategy of exploratory laparotomy with no cytology testing (ELNC) among GC patients.

METHODS

We developed a decision-analytic Markov model of the aforementioned three strategies for a hypothetical cohort of GC patients with curative intent after initial imaging, from the perspective of Chinese society. We estimated costs, quality-adjusted life years (QALYs), and incremental cost-effectiveness ratios (ICERs) as primary outcomes; we also conducted one-way and probabilistic sensitivity analyses to investigate the model's robustness.

RESULTS

We found that ELNC was dominated (i.e., more expensive and less effective) by PPL and LPL. LPL was the most cost-effective method with an ICER of US$17,200/QALY compared to PPL, which was below the Chinese willingness-to-pay (WTP) threshold of US$29,313 per QALY gained. In sensitivity analyses, PPL was more likely to be cost-effective with a lower WTP threshold.

CONCLUSIONS

Cytology testing through either LPL or PPL was less expensive and more effective than ELNC among GC patients. Moreover, LPL was the most cost-effective modality at the current WTP threshold, while PPL could potentially be cost-effective in lower-income areas.

Identification of key long non-coding RNAs in gastric adenocarcinoma

BACKGROUND

Gastric cancer is the third leading cause of cancer-related deaths worldwide.

OBJECTIVE

The present study aims to identify key long non-coding RNAs (lncRNAs) and their potential roles in the pathogenesis of gastric adenocarcinoma.

METHODS

The lncRNA and mRNA expression profile between gastric adenocarcinoma and adjacent non-tumor tissues were obtained from The Cancer Genome Atlas (TCGA). Differentially expressed lncRNAs (DElncRNAs) and mRNAs (DEmRNAs) between gastric adenocarcinoma and adjacent non-tumor tissues were identified after bioinformatics analysis. DElncRNA-DEmRNA co-expression network and DElncRNA-nearby DEmRNA interaction network were constructed, respectively. Functional annotation for DEmRNAs interacted with DElncRNAs was performed. Receiver operating characteristic (ROC) analysis of selected DElncRNAs was conducted.

RESULTS

Based on TCGA, the mRNA and lncRNA expression profiles of 375 gastric adenocarcinoma and 32 adjacent non-tumor tissues were downloaded. A total of 1502 DEmRNAs and 928 DElncRNAs between gastric adenocarcinoma and adjacent non-tumor tissues were identified. HOXC-AS3 might involve with gastric adenocarcinoma by regulating a set of HOX genes (HOXC8, HOXC9, HOXC10, HOXC11, HOXC12 and HOXC13) with cis-effect. AC115619.1-APOA4/APOB and AP006216.2-APOA1/APOA4 integrations might play roles in gastric adenocarcinoma through regulating pathways of Fat digestion and absorption and Vitamin digestion and absorption. Six lncRNAs including (HOTAIR, C20orf166-AS1, PGM5-AS1, HOXC-AS3, HOXC-AS2 and AC012531.1) have excellent diagnostic value for gastric adenocarcinoma.

CONCLUSIONS

This study identifies key lncRNAs in gastric adenocarcinoma which provides clues for exploring the pathogenesis and developing potential biomarkers for gastric adenocarcinoma.

An Innovative Prognostic Model Based on Four Genes in Asian Patient with Gastric Cancer

Purpose

Gastric cancer (GC) has substantial biological differences between Asian and non-Asian populations, which makes it difficult to have a unified predictive measure for all people. We aimed to identify novel prognostic biomarkers to help predict the prognosis of Asian GC patients.

Materials and Methods

We investigated the differential gene expression between GC and normal tissues of GSE66229. Univariate, multivariate and Lasso Cox regression analyses were conducted to establish a four-gene-related prognostic model based on the risk score. The risk score was based on a linear combination of the expression levels of individual genes multiplied by their multivariate Cox regression coefficients. Validation of the prognostic model was conducted using The Cancer Genome Atlas (TCGA) database. A nomogram containing clinical characteristics and the prognostic model was established to predict the prognosis of Asian GC patients.

Results

Four genes (RBPMS2, RGN, PLEKHS1, and CT83) were selected to establish the prognostic model, and it was validated in the TCGA Asian cohort. Receiver operating characteristic analysis confirmed the sensitivity and specificity of the prognostic model. Based on the prognostic model, a nomogram containing clinical characteristics and the prognostic model was established, and Harrell’s concordance index of the nomogram for evaluating the overall survival significantly higher than the model only focuses on the pathologic stage (0.74 vs. 0.64, p < 0.001).

Conclusion

The four-gene-related prognostic model and the nomogram based on it are reliable tools for predicting the overall survival of Asian GC patients.

Comparison of overall survival of gastric neoplasms containing neuroendocrine carcinoma components with gastric adenocarcinoma: a propensity score matching study

Background

Gastric neoplasms containing neuroendocrine carcinoma (NEC) components are rare malignancies with highly aggressive behavior and a poor prognosis and include pure NEC and mixed tumors containing NEC components. We aimed to investigate whether there is a distinct difference in overall survival (OS) between gastric neoplasms containing NEC components and gastric adenocarcinoma.

Methods

Surgically resected gastric neoplasms containing NEC components (n = 180) and gastric adenocarcinomas (n = 785) from January 2013 to December 2019 at Peking University Cancer Hospital were retrospectively analysed. Patients were categorized into a surgical group and a neoadjuvant group and adjusted using propensity score matching. In the two groups, gastric neoplasms containing NEC components were divided into pure NEC and mixed tumors with less than 30% (< 30% G-HMiNEN), between 30 and 70% (G-HMiNEN) and more than 70% (> 70% G-HMiNEN) neuroendocrine carcinoma components. OS was compared between these groups and the gastric adenocarcinoma group.

Results

The OS of gastric neoplasms containing neuroendocrine NEC components was poorer than that of gastric adenocarcinomas in the surgical group, regardless of whether the percentage of neuroendocrine cancer components was less than 30%, between 30 and 70%, more than 70% or 100%. Cox multivariable regression analysis suggested that tumor category (neoplasms containing NEC components or gastric adenocarcinoma) was an independent risk factor for prognosis. Interestingly, among patients receiving neoadjuvant therapy, the difference was not significant.

Conclusions

Gastric neoplasms containing any proportion of NEC components had poorer overall survival than gastric adenocarcinoma in patients treated with surgery directly, indicating that these neoplasms are more malignant than gastric adenocarcinoma. Among the patients receiving neoadjuvant therapy, the difference in overall survival was not significant, which was in sharp contrast with the results of the surgery group, suggesting that neoadjuvant therapy may have a good effect in the treatment of these neoplasms.

Abstract 4355: Different strategies for peritoneal lavage cytology testing in the staging of gastric cancer: A cost-effectiveness analysis

Background & Aims: The positive peritoneal cytology (PCY) indicates metastasis disease in patients with gastric cancer (GC); thus, the cytology testing is directly related to subsequent treatments, patients' prognoses, and medical costs. However, the cost-effectiveness of PCY testing remains unclear. We aim to evaluate the cost-effectiveness of PCY testing by comparing two active testing strategies of a guideline-recommended intraoperative laparoscopic peritoneal lavage (ILPL) and a newly proposed preoperative percutaneous peritoneal lavage (PPPL), and a third strategy of exploratory laparotomy with no cytology testing (ELNC) among GC patients.

Methods: We developed a decision-analytic Markov model to compare the cost-effectiveness of the above three strategies for a hypothetical cohort of GC patients with curative intent after initial imaging, from the perspective of Chinese society. Quality-adjusted life-years (QALYs), transition probabilities and costs were modeled using data mainly from published literature. We performed base case analysis and measured incremental cost-effectiveness ratios (ICERs) for various strategies, which were compared to a willingness-to-pay (WTP) threshold that was set to a three-fold of Chinese gross domestic product (GDP) per capita, $29,313/QALY gained. Furthermore, we conducted both one-way and probabilistic sensitivity analyses to investigate the model's robustness.

Results: In the base case analysis, we found that ELNC was dominated (i.e., more expensive and less effective) by PPPL and ILPL. ILPL was the most cost-effective method, with an ICER of US $16,673/QALY compared to PPPL. One-way sensitivity analyses demonstrated that the exploratory laparotomy mortality following ILPL and the peritoneal cytology prevalence were the only two influential parameters within their plausible range when assessing the cost-effectiveness of PPPL and ILPL. In the probabilistic sensitivity analyses, the probability of ILPL being cost-effective was 71.3% at the WTP threshold of $29,313/QALY; however, PPPL was more likely to be cost-effective when the willing-to-pay (WTP) threshold was below $17,020/QALY gained.

Conclusion: Cytology testing for GC staging through either ILPL or PPPL dominated ELNC in patients with curative intent. Moreover, ILPL was the most cost-effective modality at the current WTP threshold, while PPPL could potentially be cost-effective in lower-income areas.

Citation Format: Qifei He, Jinyi Zhu, Anqiang Wang, Xia Li, Zhaode Bu, Jiafu Ji. Different strategies for peritoneal lavage cytology testing in the staging of gastric cancer: A cost-effectiveness analysis [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 4355.

Molecular characteristics of synchronous multiple gastric cancer

Rationale: Multiple gastric cancer (MGC) is characterized by the presence of more than two different tumors in the stomach. However, the clonal relationship and carcinogenesis of MGC remain unclear. We investigated the clonal relationship and role of germline mutations in the carcinogenesis of MGC.

Methods: We gathered 16 multiple gastric cancer patients. Thirty-three tumor samples and sixteen normal gastric tissue or blood samples were obtained from January 2016 to December 2017. We also conducted analyses for 208 gastric cancer and 49 esophagogastric junction cancer (GC-EGJ) tumors from TCGA. DNA extraction from our samples was conducted for whole-exome sequencing (WES).

Results: Tumor mutation burden (TMB) was not statistically significant within database and our data in the GC-EGJ (P=0.0591) and GC groups (P=0.3113). The mutation spectrum and signatures also showed uniform distributions in GC and GC-EGJ groups within our data and TCGA database. Among sixteen patients, four were identified as monoclonal, in which 11, 10, 26 and 6 somatic mutations were shared within different tumors of P7, P8, P9 and P16, respectively. However, no common mutation between different tumors of the same patient was found among the other 12 patients. After identifying predisposing genes, we found that germline MSH2 and NCOR2 mutations were significantly dominant in 8/12 and 10/12 of genetic MGC patients. Additionally, all patients were identified with MSH2 mutations in cancer samples of those genetic MGC patients. Taking genetic MGCs as a whole, we identified that TP53 were significantly mutated in 14 of 25 tumor samples.

Main conclusions: WES analyses are suggestive of monoclonal and polyclonal origin of MGC, which may promote the classification of MGC into genetic and metastatic MGC. For patients with genetic MGC, germline MSH2 X314_splice variants may contribute to carcinogenesis, thus prompting the consideration of more radical surgery and/or anti-PD-1/PD-L1 therapy.

Multi-omics characterization of molecular features of gastric cancer correlated with response to neoadjuvant chemotherapy

Neoadjuvant chemotherapy is a common treatment for patients with gastric cancer. Although its benefits have been demonstrated, neoadjuvant chemotherapy is underutilized in gastric cancer management, because of the lack of biomarkers for patient selection and a limited understanding of resistance mechanisms. Here, we performed whole-genome, whole-exome, and RNA sequencing on 84 clinical samples (including matched pre- and posttreatment tumors) from 35 patients whose responses to neoadjuvant chemotherapy were rigorously defined. We observed increased microsatellite instability and mutation burden in nonresponse tumors. Through comparisons of response versus nonresponse tumors and pre- versus posttreatment samples, we found that C10orf71 mutations were associated with treatment resistance, which was supported by drug response data and potentially through inhibition of cell cycle, and that MYC amplification correlated with treatment sensitivity, whereas MDM2 amplification showed the opposite pattern. Neoadjuvant chemotherapy also reshapes tumor-immune signaling and microenvironment. Our study provides a critical basis for developing precision neoadjuvant regimens.

Impact of postoperative major complications on long-term survival after radical resection of gastric cancer

Background

This study was designed to evaluate the impact of postoperative major complications on long-term survival following curative gastrectomy.

Methods

This retrospective study included 239 patients with gastric cancer undergoing gastrectomy at the Beijing Cancer Hospital from February 2012 to January 2013. Survival curves were compared between patients with major complications (mC group) and those without major complications (NmC group). Multivariate analysis was conducted to identify independent prognostic factors.

Results

Postoperative complication and mortality rates were 24.7 and 0.8%, respectively. The severity of complications was graded in accordance with the Clavien–Dindo classification. The incidence of minor complications (grades I-II) and major complications (grades III–V) was 9.2 and 15.5%, respectively. The 3-year overall survival (OS) and disease-free survival (DFS) rates were better in the NmC group than in the mC group (p = 0.014, p = 0.013). Multivariate analysis identified major complications as an independent prognostic factor for OS and DFS. After stratification by pathological stage, this trend was also observed in stage II patients.

Conclusions

Postoperative major complications adversely affect OS and DFS. The prevention and early diagnosis of complications are essential to minimize the negative effects of complications on surgical safety and long-term patient survival.

Multicenter study of surgical and oncologic outcomes of extra-levator versus conventional abdominoperineal excision for lower rectal cancer

BACKGROUND

The surgical and oncological outcome of extra-levator abdominoperineal excision (ELAPE) procedure remains unclear in low rectal cancer.

METHODS

A total of 194 cases of rectal cancer patients underwent ELAPE or conventional abdominoperineal excision (APE) procedure were analyzed in four hospitals' databases from January 2010 to December 2015. Clinicopathological data, overall survival (OS), disease free survival (DFS) and local recurrence free survival (LRFS) of patients were compared between two groups.

RESULTS

The operation time spent in perineal phase was significantly shorter in the ELAPE group than that in conventional APE procedure (P < 0.001). There were more specimens with excellent or good quality in ELAPE group compared to conventional APE group (P = 0.033). Patients whom underwent ELAPE procedures showed significantly better OS, DFS and LRFS than those underwent conventional APE procedures. Patients with preoperative stage cT3∼T4 (P = 0.033, P = 0.008, P = 0,033), cN+ (P = 0.002, P < 0.001, P = 0.006) and pathological stage III-IV (P = 0.023, P = 0.008, P = 0.016) were associated with significant benefits from ELAPE procedure in terms of OS, DFS and LRFS. DFS differed significantly between two groups of patients whom got preoperative chemoradiation therapy (P = 0.009) or postoperative chemotherapy (P = 0.029). For patients of pathological stage IIII-IV without preoperative chemoradiation, ELAPE procedures resulted in statistically better OS (P = 0.018) and DFS (P = 0.030). ELAPE procedure was an independent risk factor of OS, DFS and LRFS in multivariate analysis.

CONCLUSION

Low rectal cancer patients might benefit from ELAPE procedure on both surgical and oncological outcomes, especially in patients with relatively advanced tumors, inspite of the effects of pre-operative radio- and chemotherapy.

Abstract 1417: Multiple gastric cancer and predisposing genes

BACKGROUND: Multiple gastric cancer (MGC) is one special type of gastric cancer with more than two different tumors at various locations of stomach. However, the clonal relationship and carcinogenesis of MGC are still remain unclear. Therefore, we investigated the clonal relationship and role of germline mutations playing in the carcinogenesis of MGC.

METHODS: We collected 16 multiple gastric cancer patients who underwent subtotal and total gastrectomy at Peking Cancer Hospital form January 2016 to December 2017. Thirty-three tumor samples and sixteen normal gastric tissue or blood samples were obtained for experiment. We also conducted analysis for 208 gastric cancer and 49 esophagogastric junction cancer (GC-EGJ) tumors from TCGA. DNA extraction from our samples was conducted for whole exome sequencing. We analyzed nonsynonymous mutations and somatic copy number variations (CNVs) based on exome data. Driver mutations, germline and cancer predisposing genes, significantly mutated genes (SMGs) were also analyzed.

RESULTS: Tumor mutation burden (TMB) was not statically significant within database and our data in GCs-EGJ groups (P=0.0591). And the TMB level was also similar between two databases in GCs groups (P=0.3113). The mutation spectrum and mutation signatures also showed uniform distributions in GCs and GCs-EGJ groups within our data and TCGA database. Among sixteen patients, four were identified as monoclonal, in which 11, 10, 26 and 6 somatic mutations were shared within different tumors of P7, P8, P9 and P16 respectively. However, no common mutation between different tumors of same patient was found from the other 12 patients in spite of thousands of somatic mutations in P2. After identifying predisposing genes, we found that germline MSH2 and NCOR2 mutations were significantly dominant in 8/12 and 10/12 of genetic MGCs patients. And all patients were identified MSH2 mutations in cancer samples of those same patients. Interestingly, the NCOR2 mutations were not detected significantly with non-frameshift INDELs in only three patients. Taking genetic MGCs as a whole, we identified that TP53 were significantly mutated in 14 of 25 tumor samples. And MSH2 mutations were found in all patients. The correlation analysis between clinical information and mutation signatures showed that the signature B was associated with the level of CA72.4.

CONCLUSIONS: Whole exome sequencing analyses are suggestive of monoclonal and polyclonal origin of MGC, which may promote the classification MGC into genetic and metastatic MGC. For genetic MGC patients, germline MSH2 mutations may contribute to the carcinogenesis of them, may thus giving rise to the consideration of more radical surgery and PD-1/PD-L1 therapy.

Citation Format: Anqiang Wang, Zhongwu Li, Xin Ji, Tao Fu, Xiaojiang Wu, Ji Zhang, Zhaode Bu, Jiafu Ji. Multiple gastric cancer and predisposing genes [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1417.