Clinical outcomes and biomarker exploration of first-line PD-1 inhibitors plus chemotherapy in patients with low PD-L1-expressing of gastric or gastroesophageal junction adenocarcinoma.

BACKGROUND: The beneficial effects of first-line programmed death-1 (PD-1) inhibitors plus chemotherapy in patients with low programmed death-ligand 1 (PD-L1)-expressing advanced gastric or gastroesophageal junction (G/GEJ) adenocarcinoma are controversial. METHODS: We conducted a retrospective analysis of patients with G/GEJ adenocarcinoma who had undergone first-line treatment with PD-1 inhibitors plus chemotherapy between October 2017 and May 2022. The primary outcomes were objective response rate (ORR) and progression-free survival (PFS). SPSS software V27.0 was used for data analysis. RESULTS: Of 345 enrolled patients, 290 had measurable lesions. The overall ORR was 59.3%. PD-L1 status was available in 171 patients, and 67.8% of them were considered as low PD-L1 expression level (combined positive score (CPS) < 5). Patients with PD-L1 CPS < 5 showed a lower response rate (51.1% vs 70.8%, P = 0.024) and a worse PFS (P = 0.009) compared to those with PD-L1 CPS ≥ 5. In the PD-L1 low-expression cohort, patients with non-diffuse type, GEJ cancer, synchronous metastasis, distant lymph node metastasis, liver metastasis, non-peritoneal metastasis, and HER2 positive were significantly associated with higher response rates to PD-1 inhibitors plus chemotherapy (P < 0.05). The presence of peritoneal metastasis (P = 0.028) and diffuse type (P = 0.046) were identified as independent predictors of poor PFS in multivariate analysis of the PD-L1 CPS < 5 subgroup. When evaluated for correlation with overall survival (OS) in the PD-L1 low-expression subgroup, peritoneal metastasis was found to be the only independent prognostic factor of an increased risk of death (hazard ratio: 2.31, 95% CI 1.09-4.90; P = 0.029). CONCLUSIONS: PD-L1 CPS ≥ 5 is significantly associated with improved response and extended PFS in G/GEJ cancer patients treated with a combination of PD-1 inhibitors and chemotherapy. Specific subgroups within the low PD-L1-expressing population, such as those with non-diffuse-type tumors and without peritoneal metastases, may also benefit from immunotherapy combined with chemotherapy.

The relationship between brain metastasis and HER2 expression status in gastric cancer

Background Brain metastasis (BM) in gastric cancer (GC) is underestimated, and human epidermal growth factor receptor 2 (HER2) overexpression is a durable poor prognostic factor. We explored the relationship between the two and made a survival analysis. Methods HER2 expression and BM status were collected from GC patients who were diagnosed between December 2009 and May 2021. We collected GC patients diagnosed between 2010 and 2016 from the SEER database. The primary endpoint was survival from the diagnosis of BM. Multivariable logistic regression was used to determine potential risk factors of BM at diagnosis in SEER database. Survival analysis was performed using the Kaplan–Meier method. Result There were 513 HER2-positive GC patients, including 16 (3.1%) with BM. Among 38 brain metastasis GC patients we collected, 16 (42.1%) patients were HER2 positive. We collected 34,199 GC patients from the SEER database and there were 260 (0.76%) patients with BM at diagnosis. GC patients that are male, white, of younger age, with primary lesions located in the proximal stomach or with distant lymph nodes, liver, bone, or lung metastasis are more likely to develop BM. The median overall survival time from diagnosis of BM was 12.73 months, and the survival time from brain metastasis of HER2-positive patients was numerically shorter, though the difference was not significant (5.30 months vs.16.13 months, P = 0.28.) Conclusion The incidence of BM in patients with HER2-positive gastric cancer is 4.08 times higher than that in general patients. The median overall survival time from BM is shorter for HER2-positive patients (AU)

The relationship between brain metastasis and HER2 expression status in gastric cancer.

BACKGROUND: Brain metastasis (BM) in gastric cancer (GC) is underestimated, and human epidermal growth factor receptor 2 (HER2) overexpression is a durable poor prognostic factor. We explored the relationship between the two and made a survival analysis. METHODS: HER2 expression and BM status were collected from GC patients who were diagnosed between December 2009 and May 2021. We collected GC patients diagnosed between 2010 and 2016 from the SEER database. The primary endpoint was survival from the diagnosis of BM. Multivariable logistic regression was used to determine potential risk factors of BM at diagnosis in SEER database. Survival analysis was performed using the Kaplan-Meier method. RESULT: There were 513 HER2-positive GC patients, including 16 (3.1%) with BM. Among 38 brain metastasis GC patients we collected, 16 (42.1%) patients were HER2 positive. We collected 34,199 GC patients from the SEER database and there were 260 (0.76%) patients with BM at diagnosis. GC patients that are male, white, of younger age, with primary lesions located in the proximal stomach or with distant lymph nodes, liver, bone, or lung metastasis are more likely to develop BM. The median overall survival time from diagnosis of BM was 12.73 months, and the survival time from brain metastasis of HER2-positive patients was numerically shorter, though the difference was not significant (5.30 months vs.16.13 months, P = 0.28.) CONCLUSION: The incidence of BM in patients with HER2-positive gastric cancer is 4.08 times higher than that in general patients. The median overall survival time from BM is shorter for HER2-positive patients.

ADAR1-mediated RNA editing of SCD1 drives drug resistance and self-renewal in gastric cancer.

Targetable drivers governing 5-fluorouracil and cisplatin (5FU + CDDP) resistance remain elusive due to the paucity of physiologically and therapeutically relevant models. Here, we establish 5FU + CDDP resistant intestinal subtype GC patient-derived organoid lines. JAK/STAT signaling and its downstream, adenosine deaminases acting on RNA 1 (ADAR1), are shown to be concomitantly upregulated in the resistant lines. ADAR1 confers chemoresistance and self-renewal in an RNA editing-dependent manner. WES coupled with RNA-seq identify enrichment of hyper-edited lipid metabolism genes in the resistant lines. Mechanistically, ADAR1-mediated A-to-I editing on 3'UTR of stearoyl-CoA desaturase (SCD1) increases binding of KH domain-containing, RNA-binding, signal transduction-associated 1 (KHDRBS1), thereby augmenting SCD1 mRNA stability. Consequently, SCD1 facilitates lipid droplet formation to alleviate chemotherapy-induced ER stress and enhances self-renewal through increasing ß-catenin expression. Pharmacological inhibition of SCD1 abrogates chemoresistance and tumor-initiating cell frequency. Clinically, high proteomic level of ADAR1 and SCD1, or high SCD1 editing/ADAR1 mRNA signature score predicts a worse prognosis. Together, we unveil a potential target to circumvent chemoresistance.

Dissected subgroups predict the risk of recurrence of stage II colorectal cancer and select rational treatment.

Background: Stage II colorectal cancer(CRC) patients after surgery alone have a five-year survival rate of ~60-80%; the incremental benefit of adjuvant chemotherapy is <5%. Predicting risk of recurrence and selecting effective personalized adjuvant drugs for stage II CRC using formalin-fixed, paraffin-embedded(FFPE) samples is a major challenge. Methods: 1319 stage II CRC patients who enrolled in 2011-2019 at Sun Yat-sen University Cancer Center were screened. RNAseq data of FFPE tumor samples of 222 stage II microsatellite stable(MSS) CRC patients(recurrence (n=47), norecurrence (n=175), median follow-up=41 months) were used to develop a method TFunctionalProg for dissecting heterogeneous subgroups of recurrence and predicting risk of recurrence. Results: TFunctionalProg showed significant predictive values in 222 stage II MSS CRCs. The TFunctionalProg low-risk group had significantly better recurrence free survival (validation set: HR=4.78, p-value=1e-4, low-risk group three-year recurrence free survival=92.6%, high-risk group three-year recurrence free survival=59.7%). TFunctionalProg dissected two subgroups of transition states of stage II MSS CRCs at a high risk of recurrence; each state displays distinct levels of hybrid epithelial-mesenchymal traits, CD8+ T cell suppression mechanisms and FOLFOX resistance. Based on mechanisms in two subgroups, TFunctionalProg proposed personalized rational adjuvant drug combinations of immunotherapy, chemotherapy and repurposed CNS drugs. TFunctionalProg provides different utilities from ctDNA-based prognostic biomarkers. Conclusion: TFunctionalProg was validated using FFPE samples to predict the risk of recurrence and propose rational adjuvant drug combinations for stage II CRC.

Prognostic and predictive value of Immunoscore and its correlation with ctDNA in stage II colorectal cancer.

This study aimed to validate the prognostic value of Immunoscore (IS) in stage II colorectal cancer (CRC), and explore the roles of IS and circulating tumor DNA (ctDNA) in the adjuvant treatment for early-stage CRC. Resected tumor samples from stage II CRC patients were collected from the Sun Yat-sen University Cancer Center. The densities of CD3+ and CD8+ lymphocytes were quantified and converted to IS and classified into Low, Intermediate (Int), and High groups according to predefined cutoffs. A total of 113 patients were included in the study. Patients with IS-High, Int, and Low were 43 (38%), 62 (55%), and 8 (7%), respectively. Patients with IS-High had an excellent clinical outcome, with none recurring during a median follow-up of 3 years, including 15 (35%) clinical high-risk patients. The 3-year disease-free survival (DFS) was 100% for IS-High, 76% for IS-Int, and 47% for IS-Low (P < .001). In the multivariate Cox analysis, IS was the only significant parameter associated with DFS. IS-Int and IS-Low patients with adjuvant chemotherapy had improved DFS compared to those who did not receive adjuvant chemotherapy (HR = 0.3; 95% CI 0.1-0.92; P = .026). Among the 49 patients with postoperative ctDNA data, IS-High patients had the lowest ctDNA positivity rate, suggesting that they were most eligible for chemotherapy-free treatment. IS had a strong prognostic value in Chinese patients with stage II CRC and demonstrates its clinical utility. IS and ctDNA will jointly optimize the adjuvant treatment strategies for early-stage CRC.

Spatial transcriptome unveils a discontinuous inflammatory pattern in proficient mismatch repair colorectal adenocarcinoma.

The preexistence of immune cells in the tumor microenvironment substantiates the efficacy of immunotherapy in cancer patients. Although the complex intratumoral immune heterogeneity has been extensively studied in single cell resolution, hi-res spatial investigations are limited. In this study, we performed a spatial transcriptome analysis of 4 colorectal adenocarcinoma specimens and 2 paired distant normal specimens to identify the molecular pattern involved in a discontinuous inflammatory response in pathologically annotated cancer regions. Based on the location of spatially varied gene expression, we unmasked the spatially-varied immune ecosystem and identified the locoregional "warmed-up" immune response in predefined "cold" tumor with substantial infiltration of immune components. This "warmed-up" immune profile was found to be associated with the in-situ copy number variance and the tissue remodeling process. Further, "warmed-up" signature genes indicated improved overall survival in CRC patients obtained from TCGA database.

Comparison of response evaluation criteria in solid tumors and tumor regression grade in evaluating the effect of preoperative systemic therapy of gastric cancer.

BACKGROUND: Both Response Evaluation Criteria in Solid Tumors (RECIST) and tumor regression grade (TRG) play key roles in evaluating tumor response. We analyzed the consistency of TRG and RECIST 1.1 for gastric cancer (GC) patients and compared their prognostic values. METHODS: Patients with GC who received preoperative chemotherapy or chemoimmunotherapy and had records of TRG from December 2013 to October 2021 were enrolled retrospectively. TRG 0-1 and 2-3 are considered as corresponding to complete response (CR)/partial response (PR) and stable disease (SD)/progress disease (PD) in RECIST 1.1, respectively. The primary endpoints were disease-free survival (DFS) and overall survival (OS). The consistency of RECIST and TRG was examined by kappa statistics. Survival analysis was performed using the Kaplan Meier method. RESULT: One hundred fifty seven GC patients were enrolled, including 125 with preoperative chemotherapy and 32 with chemoimmunotherapy. Among them, 56 patients had measurable lesions. Only 19.6% (11/56) of the patients had consistent results between RECIST 1.1 and TRG. TRG was correlated with both OS and DFS (P = 0.02 and 0.03, respectively) while response according to RECIST1.1 was not (P = 0.86 and 0.23, respectively). The median DFS had not reached in the TRG 0-1 group and was 16.13 months in TRG 2-3 group. TRG 2-3 was associated with young age and peritoneal or liver metastasis. Besides, preoperative chemoimmunotherapy had a significantly higher pCR rate than chemotherapy alone (34.4% vs 8.0%, P < 0.001). CONCLUSION: TRG was in poor agreement with RECIST 1.1. TRG was better than RECIST 1.1 in predicting DFS and OS for GC patients who received preoperative therapy.

PIM2 Expression Induced by Proinflammatory Macrophages Suppresses Immunotherapy Efficacy in Hepatocellular Carcinoma.

Cancer immunotherapy restores or enhances the effector function of T cells in the tumor microenvironment, but the efficacy of immunotherapy has been hindered by therapeutic resistance. Here, we identify the proto-oncogene serine/threonine protein kinase PIM2 as a novel negative feedback regulator of IFNγ-elicited tumor inflammation, thus endowing cancer cells with aggressive features. Mechanistically, IL1ß derived from IFNγ-polarized tumor macrophages triggered PIM2 expression in cancer cells via the p38 MAPK/Erk and NF-κB signaling pathways. PIM2+ cancer cells generated by proinflammatory macrophages acquired the capability to survive, metastasize, and resist T-cell cytotoxicity and immunotherapy. A therapeutic strategy combining immune checkpoint blockade (ICB) with IL1ß blockade or PIM2 kinase inhibition in vivo effectively and successfully elicited tumor regression. These results provide insight into the regulatory and functional features of PIM2+ tumors and suggest that strategies to influence the functional activities of inflammatory cells or PIM2 kinase may improve the efficacy of immunotherapy. SIGNIFICANCE: Cross-talk between T cells and macrophages regulates cancer cell PIM2 expression to promote cancer aggressiveness, revealing translational approaches to improve response to ICB in hepatocellular carcinoma.

Optimizing Chemotherapy of Pancreatic Acinar Cell Carcinoma: Our Experiences and Pooled Analysis of Literature.

Background: Pancreatic acinar cell carcinoma (PACC) is rare, and its appropriate treatment remains unknown. We aim to explore the characteristics and optimal treatment of it. Methods: The data on clinicopathologic characteristics, molecular alteration, treatment, and survival of patients diagnosed with PACC at the Sun Yat-sen University Cancer Center from 2005 to 2020 were collected. The optimal treatment was explored by co-analyzing our results and published literatures. Results: Twenty-two PACC patients were enrolled. Eight of 17 non-metastatic patients received adjuvant chemotherapy. The patients receiving fluoropyrimidine-based regimen (n = 3) had a better median disease-free survival (mDFS) than those with gemcitabine-based regimen (n = 5) (unreached vs 27 months). Eight metastatic patients received first-line chemotherapy. Four patients received second-line chemotherapy. The objective response rate (ORR) of the fluoropyrimidine-based regimen was 85.7% (6/7), much better than that of the gemcitabine-based regimen (0/5). One patient who had responded to the first-line FOLFIRINOX (5-fluorouracil + oxaliplatin + leucovorin + irinotecan) regimen received olaparib as maintenance treatment for 5 months with good tolerance. Thirty-one published literatures, with a total of 86 cases, were included in the co-analysis. The ORR of the first-line fluoropyrimidine-based regimen (n = 47) was higher than that of gemcitabine-based regimen (n = 39) (59.6% vs 15.3%, P < .001). Eight of 11 patients treated with the FOLFIRINOX regimen achieved partial response (PR). Conclusions: For patients with metastasis, a fluorouracil-based regimen such as FOLFIRINOX may be preferred, and maintenance treatment of poly ADP-ribose polymerase (PARP) inhibitors after effective platinum-containing treatment for breast cancer susceptibility gene (BRCA) mutation patients must be assessed.

Nucleoporin 93 mediates ß-catenin nuclear import to promote hepatocellular carcinoma progression and metastasis.

Nuclear pore complex (NPC) embedded in the nuclear envelope, is the only channel for macromolecule nucleocytoplasmic transportation and has important biological functions. However, the deregulation of specific nucleoporins (Nups) and NPC-Nup-based mechanisms and their function in tumour progression remain poorly understood. Here, we aimed to identify the Nups that contribute to HCC progression and metastasis in 729 primary hepatocellular carcinoma (HCC) cases using molecular, cytological, and biochemical techniques. Our results revealed elevated Nup93 expression in HCC tissues, especially in cases with metastasis, and was linked to worse prognosis. Furthermore, Nup93 knockdown suppressed HCC cell metastasis and proliferation, while Nup93 overexpression promoted these activities. We observed that Nup93 promotes HCC metastasis and proliferation by regulating ß-catenin translocation. In addition, we found that Nup93 interacted with ß-catenin directly, independent of importin. Furthermore, LEF1 and ß-catenin facilitated the Nup93-mediated metastasis and proliferation in HCC via a positive feedback loop. Thus, our findings provide novel insights into the mechanisms underlying the Nup93-induced promotion of HCC metastasis and suggest potential therapeutic targets in the LEF1-Nup93-ß-catenin pathway for HCC therapeutics.

PD-1 antibody camrelizumab for Epstein-Barr virus-positive metastatic gastric cancer: a single-arm, open-label, phase 2 trial.

Gastric cancer (GC) patients with Epstein-Barr virus (EBV) positivity have demonstrated promising response with immunotherapy. We assessed the efficacy and safety of camrelizumab as salvage treatment in EBV-positive mGC. In this single-arm, phase 2 prospective clinical trial (NCT03755440), stage IV EBV-positive GC patients who failed/could not tolerate previous lines of chemotherapy were given intravenous camrelizumab 200 mg every 2 weeks until disease progression or unacceptable toxicity. The primary endpoint was objective response rate. Secondary endpoints were progression-free survival (PFS), overall survival (OS), disease control rate (DCR), duration of response, and toxicity. Exploratory analysis included the associations between treatment response and tumor mutation burden (TMB), programmed cell death ligand-1 (PD-L1) expression. Six eligible patients were enrolled in the first stage of the study. No patient achieved an objective response; thus, the study did not proceed to the second stage. The DCR was 67% (4/6). The median PFS rate was 2.2 months (95% CI: 1.5-not reached [NR]) and median OS was 6.8 months (95% CI: 1.7-NR). All treatment-related adverse events were grade 1-2, with reactive cutaneous capillary endothelial proliferation (n=4 [67%]) being the most commonly observed event. The only patient with PD-L1 combined positive score >1 had disease progression. Two stable disease and one disease progression were observed in three patients with TMB >10 Mut/Mb. EBV positivity may not be a good predictor for response to camrelizumab in mGC. Newer biomarkers are needed to identify EBV-positive mGC respondents who might benefit from immunotherapy.

α-Fetoprotein mRNA in situ hybridisation is a highly specific marker of hepatocellular carcinoma: a multi-centre study.

BACKGROUND: Pathologic diagnosis of hepatocellular carcinoma (HCC) can be challenging in differentiating from benign and non-hepatocytic malignancy lesions. The aim of this study was to investigate the potential utility of α-fetoprotein (AFP) mRNA RNAscope, a sensitive and specific method, in the diagnosis of HCC. METHODS: Three independent retrospective cohorts containing 2216 patients with HCC, benign liver lesions, and non-hepatocytic tumours were examined. AFP was detected using ELISA, IHC (Immunohistochemistry), and RNAscope. Glypican3 (GPC3), hepatocyte paraffin-1 (HepPar-1), and arginase-1 (Arg-1) proteins were detected using IHC. RESULTS: AFP RNAscope improved the HCC detection sensitivity by 24.7-32.7% compared with IHC. In two surgical cohorts, a panel of AFP RNAscope and GPC3 provided the best diagnostic value in differentiating HCC from benign hepatocytic lesions (AUC = 0.905 and 0.811), and a panel including AFP RNAscope, GPC3, HepPar-1, and Arg-1 yielded the best AUC (0.971 and 0.977) when distinguishing HCC from non-hepatocytic malignancies. The results from the liver biopsy cohort were similar, and additional application of AFP RNAscope improved the sensitivity by 18% when distinguishing HCC from benign hepatocytic lesions. CONCLUSIONS: AFP mRNA detected by RNAscope is highly specific for hepatocytic malignancy and may serve as a novel diagnostic biomarker for HCC.

Identification of Two Subgroups of FOLFOX Resistance Patterns and Prediction of FOLFOX Response in Colorectal Cancer Patients.

To dissect gene expression subgroups of FOLFOX resistance colorectal cancer(CRC) and predict FOLFOX response, gene expression data of 83 stage IV CRC tumor samples (FOLFOX responder n = 42, non-responder n = 41) are used to develop a novel iterative supervised learning method IML. IML identified two mutually exclusive subgroups of CRC patients that rely on different DNA damage repair proteins and resist FOLFOX. IML was validated in two validation sets (HR = 2.6, p Value = 0.02; HR = 2.36, p value = 0.02). A subgroup of mesenchymal subtype patients benefit from FOLFOX. Different subgroups of FOLFOX nonresponders may need to be treated differently.

Observational cohort study of clinical outcome in Epstein-Barr virus associated gastric cancer patients.

BACKGROUND: Epstein-Barr virus-associated gastric cancer (EBVaGC) has unique clinicopathologic features and our present understanding of its treatment outcome is limited. Here, we investigated the clinical outcomes of resectable and metastatic EBVaGC cases with regards to their respective treatment. METHODS: We retrieved the data of EBVaGC patients treated at our center from October 2014 to June 2019. The primary endpoint was overall survival (OS). Secondary endpoints were disease-free survival (DFS) for stage I-III patients, progression-free survival (PFS) and objective response rate (ORR) for stage IV patients. RESULTS: Patients classified as stage I-III accounted for 83.7% of the total 197 cases analyzed. Two patients had mismatched repair-deficiency. The 5-year OS rate of the entire cohort was 63.51% [95% (confidence interval (CI): 52.31-72.76%]. Tumor-node-metastasis (TNM) stage and gastric stump cancer were identified as independent prognostic factors for OS. The 3- and 5-year DFS rate for stage I-III patients were 83.72% (95% CI: 75.86-89.19%) and 73.83% (95% CI: 60.39-83.32%), respectively. TNM stage III, neural invasion, lymphovascular invasion, and baseline plasma EBV-DNA positive were correlated with shorter DFS. The ORR and disease control rate (DCR) for metastatic EBVaGC patients to first-line therapy were 29.0% and 90.3% (median PFS: 9.8 months), respectively, and to second-line therapy were 25.0% and 75.0%, respectively. Seven patients received anti-PD1 therapy and had an ORR of 28.5% and a median PFS of 2.8 months. CONCLUSIONS: EBVaGC patients have few metastases, long DFS, and high DCR. TNM stage and gastric stump cancer were independent prognostic factors for OS.

Signet ring cell component in pretreatment biopsy predicts pathological response to preoperative chemoradiotherapy in rectal cancer.

PURPOSE: Neoadjuvant therapy is routinely used in the management of locally advanced rectal cancer. This study aimed to evaluate the predictive value of pathological parameters in tumor response after treatment. METHODS: We reviewed the hematoxylin-eosin slides from pretreatment biopsies of 150 rectal cancer patients who received preoperative chemoradiotherapy (PCRT) at Sun Yat-sen University Cancer Center between May 2013 and June 2016. Pathological and clinical parameters were both studied. The tumor response after chemoradiotherapy was evaluated using the tumor regression grade (TRG). Logistic regression was used to evaluate the relevance between these parameters and tumor response. RESULTS: Complete tumor response (TRG0 and pCR) to PCRT was identified in 40 (26.7%) patients. The pCR rate was 93.33% (14 of 15) in cases with signet ring cell component versus 19.26% (26 of 135) in those without signet ring cell component (p < 0.001). Four cases with signet ring cell component were evaluated as clinical complete response (cCR), all of whom also achieved pCR; in contrast, only 9 of 15 (60%) cCR cases without signet ring cell achieved pCR. CONCLUSION: Our data suggest that the signet ring cell component in pretreatment biopsies may be a potential predictor of tumor response to PCRT in rectal cancer. This suggests patients with clinical complete response are more suitable for a wait-and-watch approach.

Classification of gastric cancer by EBV status combined with molecular profiling predicts patient prognosis.

PURPOSE: To identify how Epstein-Barr virus (EBV) status combined with molecular profiling predicts the prognosis of gastric cancer patients and their associated clinical actionable biomarkers. EXPERIMENTAL DESIGN: A next-generation sequencing assay targeting 295 cancer-related genes was performed in 73 EBV-associated gastric cancer (EBVaGC) and 75 EBV-negative gastric cancer (EBVnGC) specimens and these results were compared with overall survival (OS). RESULTS: PIK3CA, ARID1A, SMAD4, and PIK3R1 mutated significantly more frequently in EBVaGC compared with their corresponding mutation rate in EBVnGC. As the most frequently mutated gene in EBVnGC (62.7%), TP53 also displayed a mutation rate of 15.1% in EBVaGC. PIK3R1 was revealed as a novel mutated gene (11.0%) associated almost exclusively with EBVaGC. PIK3CA, SMAD4, PIK3R1, and BCOR were revealed to be unique driver genes in EBVaGC. ARID1A displayed a significantly large proportion of inactivated variants in EBVaGC. A notable finding was that integrating the EBV status with tumor mutation burden (TMB) and large genomic instability (LGI) categorized the tumors into four distinct molecular subtypes and optimally predicted patient prognosis. The corresponding median OSs for the EBV+/TMB-high, EBV+/TMB-low, EBV-/LGI-, and EBV-/LGI+ subtypes were 96.2, 75.3, 44.4, and 20.2 months, respectively. The different subtypes were significantly segregated according to distinct mutational profiles and pathways. CONCLUSIONS: Novel mutations in PIK3R1 and TP53 genes, driver genes such as PIK3CA, SMAD4, PIK3R1, BCOR, and ARID1A, and distinguished genomic profiles from EBVnGC were identified in EBVaGC tumors. The classification of gastric cancer by EBV, TMB, and LGI could be a good prognostic indicator, and provides distinguishing, targetable markers for treatment.

Prospective observation: Clinical utility of plasma Epstein-Barr virus DNA load in EBV-associated gastric carcinoma patients.

Epstein-Barr virus (EBV)-associated gastric carcinomas (EBVaGCs) may account for 8-9% of all gastric cancer (GC) patients. All previous reports on EBVaGC were retrospective. Prospective study is warranted to evaluate the exact role of EBV status in predicting the prognosis of GC. It is of special interest to figure out whether dynamic detection of plasma EBV-DNA load could be a feasible biomarker for the monitor of EBVaGC. From October 2014 to September 2017, we consecutively collected GC patients (n = 2,760) from Sun Yat-sen University Cancer Center for EBER examination. We detected EBV-DNA load in plasma and tissue samples of EBVaGC patients at baseline. Subsequently, plasma EBV-DNA load was dynamically monitored in EBVaGC patients. The overall prevalence of EBVaGC is 5.1% (140/2,760). The incidence rate of EBVaGC decreased with advanced AJCC 7th TNM stage (p < 0.001), with the corresponding percentages of 9.3, 9.9, 6.7 and 1.4% for Stage I, II, III and IV patients. EBVaGC patients were predominately young males with better histologic differentiation and earlier TNM stage than EBV-negative GC (EBVnGC) patients. EBVaGC patients were confirmed to had a favorable 3-year survival rate (EBVaGC vs. EBVnGC: 76.8% vs. 58.2%, p = 0.0001). Though only 52.1% (73/140) EBVaGC patients gained detectable EBV-DNA and 43.6% (61/140) reached a positive cutoff of 100 copies/ml, we found the plasma EBV-DNA load in EBVaGC decreased when patients got response, while it increased when disease progressed. Our results suggested that plasma EBV-DNA is a good marker in predicting recurrence and chemotherapy response for EBVaGC patients.

Loss of RDM1 enhances hepatocellular carcinoma progression via p53 and Ras/Raf/ERK pathways.

Hepatocellular carcinoma (HCC), with its ineffective therapeutic options and poor prognosis, represents a global threat. In the present study, we show that RAD52 motif 1 (RDM1), a key regulator of DNA double-strand break repair and recombination, is downregulated in HCC tissues and suppresses tumor growth. In clinical HCC samples, low expression of RDM1 correlates with larger tumor size, poor tumor differentiation, and unfavorable survival. In vitro and in vivo data demonstrate that knockdown of RDM1 increases HCC cell proliferation, colony formation, and cell population at G2/M phase, whereas RDM1 overexpression results in the opposite phenotypes. Mechanistically, RDM1 binds to the tumor suppressor p53 and enhances its protein stability. In the presence of p53, RDM1 suppresses the phosphorylation of Raf and ERK. Overexpression of p53 or treatment with ERK inhibitor significantly abolishes cell proliferation induced by the depletion of RDM1. In addition, overexpression of methyltransferase-like 3 markedly induces N6-methyladenosine modification of RDM1 mRNA and represses its expression. Taken together, our study indicates that RDM1 functions as a tumor suppressor and may be a potential prognostic and therapeutic factor for HCC.

Identification and external validation of a novel miRNA signature for lymph node metastasis prediction in submucosal-invasive gastric cancer patients.

Endoscopic resection (ER) has been increasingly performed in the treatment of early gastric cancer (GC). However, lymph node metastasis (LNM) can cause treatment failure with ER, especially in T1b patients. Here, we attempted to develop a miRNA-based classifier to detect LNM in T1b patients. Based on high-throughput data from The Cancer Genome Atlas, we identified 20 miRNAs whose expression significantly changed in T1-2 GC with LNM vs T1-2 GC without LNM. We then developed a miRNA signature to predict LNM of T1b GC using the LASSO model and backward step wise elimination approach in a training cohort. Furthermore, the predictive accuracy of this classifier was validated in both an internal testing group of 63 patients and an external independent group of 114 patients. This systematic and comprehensive in silico study identified a 7-miRNA signature with an area under the receiver operating characteristic curve (AUROC) value of 0.843 in T1-2 GC and 0.911 in T1 EGC. The backward elimination was further used to develop a 4-miRNA (miR-153-3p, miR-708, miR-940 and miR-375) risk-stratification model in the training cohort with an AUROC value of 0.898 in cohort 2. When pathologic results were used as a reference, the risk model yielded AUROC values of 0.829 and 0.792 in two cohorts of endoscopic biopsy specimens. This novel miRNA-LNM classifier works better than the currently used pathologic criteria of ER in T1b EGC. This classifier could individualize the management of T1b patients and facilitate treatment decisions.