Association between hepatic angiosarcoma and end-stage renal disease: nationwide population-based evidence and enriched mutational signature of aristolochic acid exposure.

Hepatic angiosarcoma (HAS) is an aggressive mesenchymal malignancy that remains underexplored with respect to its etiology and mutational landscapes. To clarify the association between HAS and end-stage renal disease (ESRD), we used nationwide data of the National Health Insurance Research Database (NHIRD) in Taiwan, covering ~99% of the population, from 2001 to 2016. To investigate molecular signatures, we performed whole-exome sequencing (WES) in 27 surgical specimens, including nine ESRD-associated cases. The NHIRD analysis demonstrated that HAS ranked second among all angiosarcomas in Taiwan, with the incidence rates of HAS being 0.08, 2.49, and 5.71 per 100,000 person-years in the general population, chronic kidney disease (CKD), and ESRD patients, respectively. The standardized incidence ratios of HAS in CKD and ESRD patients were 29.99 and 68.77, respectively. In comparison with nonhepatic angiosarcoma, the multivariate regression analysis of our institutional cohort confirmed CKD/ESRD as an independent risk factor for HAS (odds ratio: 9.521, 95% confidence interval: 2.995-30.261, p < 0.001). WES identified a high tumor mutation burden (TMB; median: 8.66 variants per megabase) and dominant A:T-to-T:A transversion in HAS with frequent TP53 (81%) and ATRX (41%) mutations, KDR amplifications/gains (56%), and CDKN2A/B deletions (48%). Notably, ESRD-associated HAS had a significantly higher TMB (17.62 variants per megabase, p = 0.01) and enriched mutational signatures of aristolochic acid exposure (COSMIC SBS22, p < 0.001). In summary, a significant proportion of HAS in Taiwan is associated with ESRD and harbors a distinctive mutational signature, which concomitantly links nephrotoxicity and mutagenesis resulting from exposure to aristolochic acid or related compounds. A high TMB may support the eligibility for immunotherapy in treating ESRD-associated HAS. © 2023 The Pathological Society of Great Britain and Ireland.

The origin of regulatory from the effector cells in LAG-3-marked Th1 immunity against severe influenza virus infection.

In severe respiratory virus infections, including influenza, an exaggerated host immune response has been linked to the severe disease and death. Control of the overwhelming immune response is thus essential. Efforts with broad-spectrum immunosuppressive agents such as steroids are disappointing. A better understanding of host immune response using animal experimental system is required to avoid undesired outcome of experimental manipulation. Following severe influenza virus infection in influenza hemagglutinin antigen-specific transgenic mouse experimental model, step-wise evolving cells from a pool of naïve hemagglutinin-specific CD4+ T cells were studied for phenotypic, genomic, and functional characterization in vivo. Naïve CD4+ T cells respond with Th1 commitment in the absolute majority. They first develop into LAG-3Med IFN-γ-secreting Th1 effectors and then evolve into LAG-3High IFN-γ-not-secreting regulators with increasing LAG-3 expression upon continuous activation and cell division. The LAG-3Med IFN-γ-secreting effectors contribute to inflammation, boost inflammatory response of cognate antigen-specific CD8+ T cells, and aggravate the disease despite facilitated virus clearance. In contrast, LAG-3High regulators do not contribute to inflammation, suppress CD8+ T cell inflammatory response, alleviate lung pathology, and ameliorate the disease with preserved virus clearance. Moderated CD8+ T cells retain proliferative capacity, and persist beyond virus clearance. Such moderation is distinct from Foxp-3+ regulator-mediated suppression, which suppresses proliferative and inflammatory responses of the CD8+ T cells and impairs virus clearance with inflammation alleviation. Origin of regulatory from the effector cells of LAG-3-marked Th1 immunity alleviates lung inflammation without impairment of virus eradication.

A Single-Institute Experience with C-ros Oncogene 1 Translocation in Non-Small Cell Lung Cancers in Taiwan.

(1) Background: The C-ros oncogene 1 (ROS1) gene translocation is an important biomarker for selecting patients for crizotinib-targeted therapy. The aim of this study was to understand the incidence, diagnostic algorithm, clinical course and objective response to crizotinib in ROS1 translocated lung non-small cell lung cancers (NSCLCs) in Taiwan. (2) Methods: First, we retrospectively studied the ROS1 status in 100 NSCLC samples using break-apart fluorescent in situ hybridization (FISH) and immunohistochemical (IHC) staining to establish a diagnostic algorithm. Then, we performed routine ROS1 IHC tests in 479 NSCLCs, as crizotinib was available from 2018 in Taiwan. We analyzed the objective response rate and the survival impact of crizotinib. (3) Results: Four ROS1 translocations were clustered in epidermal growth factor receptor (EGFR) wild-type adenocarcinomas but not in cases with EGFR mutations. Strong ROS1 expression was positively correlated with ROS1 translocation (p < 0.001). NSCLCs with ROS1 translocation had a poor prognosis compared to those without ROS1 translocation (p = 0.004) in the pre-crizotinib stage. Twenty NSCLCs were detected with ROS1 translocation in 479 wild-type EGFR specimens from 2018. Therefore, the incidence of ROS1 translocation is approximately 4.18% in EGFR wild-type NSCLCs. In these 20 ROS1 translocation cases, 19 patients received crizotinib treatment, with an objective response rate (ORR) of 78.95% (confidence interval = 69.34% to 88.56%), including 1 complete response, 14 partial responses, 3 stable cases and 1 progressive case. Overall survival and progression-free survival were better in the 19 ROS1-translocated NSCLCs of the prospective group with crizotinib treatment than the four ROS1-translocated NSCLCs of the retrospective group without crizotinib treatment. (4) Conclusions: ROS1-translocated NSCLCs had a poor prognosis and could have a beneficial outcome with crizotinib.

Is Adjuvant Chemotherapy Necessary for Patients with Deficient Mismatch Repair Gastric Cancer?-Autophagy Inhibition Matches the Mismatched.

PURPOSE: The use of microsatellite instability (MSI) and mismatch repair (MMR) as predictive biomarkers for fluorouracil-based adjuvant chemotherapy in colorectal cancer has been a paradigm shift. However, whether this applies to gastric cancer is questionable. Furthermore, we herein investigated whether and how autophagy plays a role in MSI-relevant chemoresistance. MATERIALS AND METHODS: A total of 929 patients with deficient MMR (dMMR) and proficient MMR (pMMR) gastric cancers who underwent curative-intent gastrectomy were enrolled. We compared clinicopathological variables and survival among dMMR and pMMR cohorts and tested the responses of MSI-high and microsatellite stable (MSS) gastric cancer cell lines to 5-fluorouracil (5-FU) with or without chloroquine, an autophagy inhibitor. RESULTS: We identified an 8.9% prevalence of dMMR cases (83 out of 929) in our cohort. This was associated with old age, tumor site at the distal stomach, an intestinal phenotype, fewer nodal metastasis, and early pathological stages. MMR was an independent prognostic factor after multivariate adjustment. Overall survival (OS) of dMMR patients was better than that of the pMMR patients but was only applicable to stage III patients. There was no difference in OS between dMMR patients treated with or without adjuvant chemotherapy, although the latter showed more medical morbidities. The MSI-high gastric cancer cell lines, versus the MSS counterparts, displayed increased resistance to 5-FU and increased autophagy. Interestingly, autophagy inhibition abrogated the chemoresistance. CONCLUSION: Our data show that fluorouracil-based adjuvant chemotherapy does not work for dMMR cases, if not worse. Autophagy inhibition and/or immune checkpoint inhibition might be promising alternative strategies for gastric cancer treatment. IMPLICATIONS FOR PRACTICE: The use of microsatellite instability (MSI) and mismatch repair (MMR) as predictive biomarkers for adjuvant chemotherapy in colorectal cancer has caused a paradigm shift in cancer therapy, although its implications in gastric cancer are still questionable. The data obtained in the current study indicate that MSI-MMR is an independent prognostic factor for gastric cancer. Standard fluorouracil-based adjuvant chemotherapy did not work for deficient MMR cases, and was likely worse. Instead, strategies like autophagy inhibition and/or immune checkpoint inhibition should be taken into consideration in the future.

The clinicopathological and molecular analysis of gastric cancer with altered SMARCA4 expression.

AIMS: In this study, we examine the clinicopathological and molecular features of gastric cancer (GC) with SMARCA4 alterations. METHODS AND RESULTS: We screened SMARCA4 alterations using immunohistochemistry on 1199 surgically resected GCs with information on Epstein-Barr virus (EBV), microsatellite instability (MSI) and other SWI/SNF subunits. SMARCA4, SMARCA2 and ARID1A mutations were investigated by targeted sequencing. The clinicopathological significance was determined by statistical analysis. Twenty-seven cases (2%) with altered SMARCA4 expression were identified, exhibiting completely lost (six), reduced (nine) or heterogeneous (12) patterns. Frequent concomitant alterations of other SWI/SNF subunits were noted with an unusual discordant spatial heterogeneity. In comparison with SMARCA4-retained GCs, SMARCA4-lost GCs were observed more frequently in the non-EBV/MSI subgroup (five of six) and reduced or heterogeneous SMARCA4 expression mainly occurred in EBV- or MSI-associated cases (six of nine and six of 12, respectively; P < 0.001). Histologically, SMARCA4-altered GC, irrespective of expression pattern, demonstrated divergent histomorphology, spanning tubular, poorly cohesive or mixed, neuroendocrine to solid and undifferentiated carcinoma, with a predilection to the latter two (P < 0.001). De-differentiation-like transition and rhabdoid features were noted in a minority of cases. For overall survival, altered SMARCA4 expression was an unfavourable prognostic factor in stage III, EBV-associated GC and non-EBV/MSI intestinal subtype (P ≤ 0.001). SMARCA4 or ARID1A mutations were detected mainly in SMARCA4-lost or reduced GC, respectively. CONCLUSIONS: SMARCA4-altered GCs are rare and have intratumoral heterogeneity, histomorphological diversity, conditional prognostic significance and various genetic drivers. SMARCA4-lost GC may represent a genuine SMARCA4-deficient neoplasm, but most SMARCA4-reduced/heterogeneous cases are secondary to ARID1A collapse or associated with different genotypes.

Different surgical outcome and follow-up status between dMMR and pMMR colorectal cancer patients who fulfilled with Amsterdam-II criteria.

BACKGROUND: Although hereditary non-polyposis colorectal cancer (HNPCC) could be subtyped into proficient or deficient mismatch repair gene expression (pMMR or dMMR), distinct clinical features between these two subgroups patients were rarely reported. METHODS: We retrospectively analyzed 175 hereditary non-polyposis colorectal cancer (HNPCC) patients between January 1995 and December 2012. Cox proportional hazards model was used to compare the differences between two subgroups. RESULTS: Significant differences of disease free survival (DFS) and overall survival (OS) exist between dMMR and pMMR. In addition to other factors including younger mean age of diagnosis for dMMR patients (48.6 years vs. 54.3 years), operation type (more extended colectomy for dMMR 35.8% vs. 14.5%), tumor location (right colon predominance for dMMR 61.7% vs. 27.3% and more rectum cases for pMMR 41.8% vs. 11.7%), tumor differentiation (more poor differentiation for dMMR 23.3% vs. 9.0%), N staging (more N0 cases for dMMR 70.8% vs. 50.9%), more frequently presence of extra-colonic tumors for dMMR (16.7% vs.1.8%), and lower recurrence rates (9.1% vs.35.3%). Significantly different cumulative incidences of developing metachronous colorectal cancer were observed with 6.18 for pMMR patients and 20.57 person-years for dMMR patients (p < 0.001). CONCLUSIONS: Distinct clinicopathological features significantly exist between dMMR and pMMR subtypes patient, MMR status should be consider to tailor operation types and follow up surveillance between these two subgroups patients who all fulfilled with Amsterdam-II criteria.

Subtraction of Epstein-Barr virus and microsatellite instability genotypes from the Lauren histotypes: Combined molecular and histologic subtyping with clinicopathological and prognostic significance validated in a cohort of 1,248 cases.

Limited studies investigated clinicopathological and prognostic significance of histologic and molecular subgroups of gastric cancer concurrently. We retrospectively enrolled 1,248 patients with gastric cancer who received radical gastrectomy with lymphadenectomy and classified these cases into the Epstein-Barr virus (EBV)-associated and microsatellite instability (MSI)-associated subtypes by EBV-encoded small RNA in situ hybridization and immunohistochemical stains for DNA mismatch repair proteins, respectively. The remaining cases were categorized as the Lauren intestinal and diffuse/mixed subtypes. The clinicopathological and prognostic significance of the subtypes was examined by statistical analysis. In total, 65 (5.2%), 116 (9.3%), 496 (39.7%), 431 (34.5%) and 140 (11.2%) cases were identified as EBV-associated, MSI-associated, intestinal, diffuse and mixed subtypes, respectively. The EBV-associated, MSI-associated, intestinal and diffuse/mixed subtypes exhibited distinctive clinicopathological characteristics, including differences in age, gender, stump cancer, gastric location, tumor size, TNM stage, margin involvement, lymphatic/perineural invasion, HER2 status and recurrence pattern. The log-rank test showed survival discrimination (p < 0.001), and the multivariate analysis identified EBV-associated and MSI-associated cases demonstrated better outcomes than the diffuse/mixed subtype (EBV, HR 0.464, 95% CI 0.296-0.727, p = 0.001; MSI, HR 0.590, 95% CI 0.407-0.856, p = 0.005). EBV-associated lymphoepithelioma-like carcinoma cases had the most favorable outcome (HR 0.138, 95% CI 0.033-0.565, p = 0.006). In different clinical groups, the subtypes exhibited survival discrepancies. The EBV-associated and diffuse/mixed cases exhibited more favorable response to chemotherapy. In conclusion, this combined classification, in parallel with the molecular subtypes specified in the Cancer Genome Atlas study, has implications for the clinical management of gastric cancer.

Au Nanoparticles Deposited on Magnetic Carbon Nanofibers as the Ultrahigh Sensitive Substrate for Surface-Enhanced Raman Scattering: Detections of Rhodamine 6G and Aromatic Amino Acids.

Surface-enhanced Raman scattering (SERS) is a unique spectroscopy that can offer high-sensitive detection for many molecules. Herein, the Au particles deposited on carbon nanofiber-encapsulated magnetic Ni nanoparticles (NPs) (Ni@CNFs@Au) have been successfully synthesized for SERS measurements. The Ni@CNFs@Au substrates have the advantages of a high SERS sensitivity and good magnetic response. The Ni@CNFs could be directly obtained from CO2 hydrogenation on a Ni catalyst, which has been characterized as having rich carboxylic acid groups, graphitic structures, and a high surface area. The Ni@CNFs surface could effectively increase the density of hotspots during Au NP aggregation and influence the morphology of the Au nanostructures. The spherical shape, oval shape, and coral-like Au nanostructures were prepared on Ni@CNFs with various Au concentrations. Brunauer-Emmett-Teller, zeta potential, high-resolution transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy measurements were used to characterize the Ni@CNFs@Au samples. The Au NPs deposited on the Ni@CNFs presented a suitable oval shape, and an average size of ∼30-40 nm. The size allowed surprisingly ultrasensitive SERS detection of rhodamine 6G (R6G) with a resolution of approximately a single molecule under an excitation wavelength of 532 nm. Using 785 nm excitation, a low R6G concentration of ∼1 × 10-14 M was detected. Moreover, the Ni@CNFs@Au substrates could be rapidly magnetically separated after adsorption. Phenylalanine and tyrosine amino acids, which are associated with the liver disease, were examined using SERS with the Ni@CNFs@Au substrate. Ultralow concentrations of ∼1 × 10-11 M for phenylalanine and ∼1 × 10-13 M for tyrosine were clearly measured. The Ni@CNFs@Au substrates exhibited applicability as excellent SERS detection platforms that combine high-sensitivity and rapid magnetic separation for various adsorption molecules.

68Ga-DOTATOC and 18F-FDG PET/CT for identifying the primary lesions of suspected and metastatic neuroendocrine tumors: A prospective study in Taiwan.

BACKGROUND/PURPOSE: To investigate the diagnostic accuracy of 68Ga-DOTATOC and 18F-FDG PET/CT to identify the primary foci in Taiwanese patients with clinically suspected neuroendocrine tumors (NET) and NET of unknown primary site. METHODS: Patients with clinically suspected NET and NET of unknown primary site were eligible. All participants underwent a conventional workup (including CT, MR, endoscopic ultrasound), 68Ga-DOTATOC, and 18F-FDG PET/CT. The results of pathology and findings on clinical follow-up served as the gold standard. RESULTS: Among the 36 patients included in the study, we were able to identify the primary tumor in 17 participants (47.2%). The overall sensitivity values of 68Ga-DOTATOC, 18F-FDG, and conventional workup were 88%, 41%, and 53%, respectively, whereas the specificities were 100%, 100%, 68%, respectively. The areas under curve of 68Ga-DOTATOC, 18F-FDG, and conventional workup were 0.941, 0.706, and 0.607, respectively. 68Ga-DOTATOC was more sensitive than 18F-FDG and more specific than conventional workup. Treatment changes as a result of 68Ga-DOTATOC PET/CT findings occurred in 12 (33.3%) of the 36 study participants. CONCLUSION: Our data confirm the usefulness of 68Ga-DOTATOC in the identification of NET. In addition, treatment modifications as a result of 68Ga-DOTATOC PET/CT findings were evident in approximately one third of NET patients.

Does a Higher Cutoff Value of Lymph Node Retrieval Substantially Improve Survival in Patients With Advanced Gastric Cancer?-Time to Embrace a New Digit.

BACKGROUND: The present study assessed the impact of the retrieval of >25 lymph nodes (LNs) on the survival outcome of patients with advanced gastric cancer after curative-intent gastrectomy. PATIENTS AND METHODS: A total of 5,386 patients who had undergone curative gastrectomy for gastric cancer from 1994 to 2011 were enrolled. The clinicopathological parameters and overall survival (OS) were analyzed according to the number of LNs examined (≤15, n = 916; 16-25, n = 1,458; and >25, n = 3,012). RESULTS: The percentage of patients with >25 LNs retrieved increased from 1994 to 2011. Patients in the LN >25 group were more likely to have undergone total gastrectomy and to have a larger tumor size, poorer tumor differentiation, and advanced T and N stages. Hospital mortality among the LN ≤15, LN 16-25, and LN >25 groups was 6.1%, 2.7%, and 1.7%, respectively (p < .0001). The LN >25 group consistently exhibited the most favorable OS, in particular, with stage II disease (p = .011) when OS was stratified according to tumor stage. Similarly, the LN >25 group had significantly better OS in all nodal stages (from N1 to N3b). The discrimination power of the lymph node ratio (LNR) for the LN ≤15, LN 16-25, and LN >25 groups was 483, 766, and 1,560, respectively. Multivariate analysis demonstrated that the LNR was the most important prognostic factor in the LN >25 group. CONCLUSION: Retrieving more than 25 lymph nodes during curative-intent gastrectomy substantially improved survival and survival stratification of advanced gastric cancer without compromising patient safety. The Oncologist 2017;22:97-106Implications for Practice: D2 lymph node (LN) dissection is currently the standard of surgical management of gastric cancer, which is rarely audited by a third party. The present study, one of the largest surgical series worldwide, has shown that the traditionally recognized retrieval of ≥16 LNs during curative-intent gastrectomy might not be adequate in regions in which locally advanced gastric cancers predominate. The presented data show that retrieval of >25 LNs, which more greatly mimics D2 dissection, improves long-term outcomes and survival stratification without compromising patient safety.

Immunochemotherapy benefits in gastric cancer patients stratified by programmed death-1 ligand-1.

BACKGROUND: Effectiveness of protein-bound polysaccharide K (PSK) during adjuvant chemotherapy in gastric cancer patients expressing programmed death-1 ligand 1 (PD-L1) has not been investigated. Investigating this might help in triaging candidates eligible to immunochemotherapy. MATERIALS AND METHODS: In total, 918 patients with stages II and III gastric cancer, undergoing curative gastrectomy, and receiving adjuvant chemotherapy were enrolled in a prospective database, and the patients were retrospectively reviewed. We classified those patients into four cohorts stratified by PD-L1 expression and PSK administration, namely PD-L1, PSK (-,+); PD-L1, PSK (-,-); PD-L1, PSK (+,+); and PD-L1, PSK (+,-). In addition, another independent cohort of 20 patients undergoing radical gastrectomy was prospectively recruited to check their immunological cells of sera before and 2 mo after PSK administration. RESULTS: PSK treatment was an independent prognostic factor for patient's overall survival (P = 0.020), whereas PD-L1 expression per se was not. Administration of PSK prolonged patient survival in stages IIIA and IIIB (P = 0.031) but not in stage II or stage IIIC. Patients with negative expression of PD-L1, treated with PSK had longer survival than those not treated with PSK (P = 0.033). PSK did not affect the survival of patients with positive expression of PD-L1, (P = 0.421). The percentages of natural killer and natural killer T (NKT) cells, but not Th1, Th17, Treg, or IFN-γ+/CD8+ T cells, were significantly increased in PD-L1 (-) patients treated with PSK. However, these findings were not evident in PD-L1 (+) patients. CONCLUSIONS: PSK treatment preferentially confers a survival gain for patients with stage IIIA/IIIB gastric cancer, especially in the PD-L1 (-) subpopulation.

Comprehensive profiling of virus microRNAs of Epstein-Barr virus-associated gastric carcinoma: highlighting the interactions of ebv-Bart9 and host tumor cells.

BACKGROUND AND AIM: Epstein-Barr virus (EBV) is suggested to actively utilize its ebv-microRNAs (miRNAs) to manipulate viral and cellular functions during neoplasia transformation. A systemic profiling of ebv-miRNAs expressed in EBV-associated gastric carcinoma (EBVa GC) helps understand its epigenetic regulation of carcinogenesis. METHODS: A total of 1039 patients with gastric cancer were screened for EBVa GC using EBV-encoded RNAs in situ hybridization. A comprehensive profiling of ebv-miRNAs expressed in EBVa GC was constructed using stem-loop quantitative polymerase chain reaction. Functional assay of specific ebv-miRNA was conducted. Expression of epithelial-to-mesenchymal transition (EMT) markers among EBVa GC and non-EBVa GC was compared. RESULTS: The prevalence of EBVa GC was 5.0% (52 out of 1039) in our series. The most abundant ebv-miRNAs of EBVa GC were Bart4, followed by Bart11, Bart2, Bart6, Bart9, and Bart18, in the decreasing order. Of them, Bart9 exhibited the same seed sequence as to hsa miR-200a and miR-141. Expression of E-cadherin of EBV-positive SNU-719 was increased after BART9 knockdown. Depleting endogenous Bart9 of SNU-719 induced a surged expression of miR-200a and miR-141, accompanied by decreased proliferative and invasive ability. Expression of mesenchymal markers in EBVa GC was increased compared with those of non-EBVa GC, albeit the two cohorts exhibited a comparable long-term survival. CONCLUSIONS: We constructed a comprehensive profiling of ebv-miRNAs in EBVa GC. BART9 plays an important role during carcinogenesis through EMT. Inherent mesenchymal phenotype of EBVa GC represents a unique virus-induced morphology and microenvironment rather than being able to predict the prognosis.

OncomiR miR-96 and miR-182 promote cell proliferation and invasion through targeting ephrinA5 in hepatocellular carcinoma.

EphrinA5, a member of the ephrinA subclass, is downregulated in hepatocellular carcinoma (HCC) and acts as a tumor suppressor. However, the upstream regulation mechanism of ephrinA5 remains unclear. In this study, we tried to identify and characterize the roles of miR-96 and miR-182 in the regulation of ephrinA5 expression in HCC. The expression levels of miR-96 and miR-182 were examined in 47 paired HCC and para-tumoral liver tissues using quantitative real-time RT-PCR. The luciferase reporter assay and western blotting were employed to dissect the association between miR-96/182 and ephrinA5 expression. Moreover, cells were treated with synthetic miR-96/182 precursors and inhibitors to assess their effects on HCC cell growth and migration. It was found that both miR-96 and miR-182 were upregulated in HCC compared to para-tumoral normal tissues. The expression of miR-96 and miR-182 was inversely associated with ephrinA5 protein levels. Furthermore, both miR-96 and miR-182 directly targeted the 3'UTR of the ephrinA5 mRNA and suppressed protein translation. The suppression of miR-96 and miR-182 led to reduced HCC cell proliferation and migration by negatively regulating ephrinA5 expression. In conclusion, miR-96 and miR-182 may act as oncomiRs in HCC by suppressing the expression of ephrinA5 and may play important roles in hepatocarcinogenesis. © 2015 Wiley Periodicals, Inc.

Association of endoscopic ultrasonographic parameters and gastrointestinal stromal tumors (GISTs): can endoscopic ultrasonography be used to screen gastric GISTs for potential malignancy?

BACKGROUND: Previous research shows that only 10-30% of gastrointestinal stromal tumors (GISTs) are malignant. Nonetheless, some reports suggest that all of them have some degree of potential for malignancy. Endoscopic ultrasonography (EUS) is a useful technique for differentiation of subepithelial lesions in the gastrointestinal tract. We explored EUS characteristics that might predict the malignancy potential of GISTs. METHODS: In this retrospective review of the medical records from 1999 through 2007, patients who had gastric stromal tumors diagnosed prior to surgery using EUS were enrolled. The EUS images, procedure records and tissue histopathology were reviewed. All patients were positive for C-kit. RESULTS: Of the 110 patients enrolled, 57 were males, and 53 were females. Most (67%) of the GISTs were located in the gastric body. The lesion size ranged from 6.3 to 150 mm (mean ± SD: 39.73 ± 22.49 mm). The high-risk GIST group had 19 (17.3%) patients, the intermediate-risk group had 12 (10.9%) patients and the low/very low-risk group had 79 (71.8%) patients. Thirty patients had cystic lesions (27.3%), while six patients had calcification in the lesion (5.5%). Additionally, 27 patients (24.5%) had surface ulceration visible on endoscopy. GISTs at high risk for malignancy were highly associated with lesion size (p < 0.0001), cystic change (p = 0.015) and surface ulceration (p = 0.036) but not with calcification (p = 0.667). We also found that mitosis was associated with lesion size (p < 0.0001) rather than other parameters. Age was not predictive of malignancy potential (p = 0.316). However, tumor size is the only one independent risk factor for malignancy (p ≤ 0.0001). CONCLUSIONS: The preliminary results show that large gastric GISTs with cystic change and surface ulceration may associate with a risk of malignancy, warranting more aggressive management. Nevertheless, the tumor size is more important than other factors.

HER2 testing in paired biopsy and excision specimens of gastric cancer: the reliability of the scoring system and the clinicopathological factors relevant to discordance.

BACKGROUND: Inclusion of trastuzumab in chemotherapy regimens is advantageous for patients with advanced or metastatic gastric cancer who overexpress HER2. Therefore, accurate assessment of HER2 status in tumor tissue is critical when weighing treatment options. METHODS: We examined HER2 expression in 180 paired endoscopic biopsy and surgical excision specimens of gastric cancers via immunohistochemistry (IHC). Equivocal IHC results (IHC 2+) were resolved by HER2 fluorescence in situ hybridization (FISH). The relationships of several clinical and pathological features with discordant HER2 results in paired specimens were determined. RESULTS: Fourteen biopsy specimens and surgical specimens (7.8%) were HER2-positive. Discordant HER2 IHC scores were observed in 90 paired specimens (50%) and 8 paired specimens (4.4%) had discordant results. The kappa coefficients for an HER2 diagnostic algorithm were 0.264, 0.339, and 0.690 for IHC scores, IHC categories, and final results, respectively (p < 0.001). Discordant HER2 results were significantly associated with discordant tumor differentiation in the paired biopsy and excision specimens (p = 0.01). Intratumoral heterogeneity did not predict HER2 discordance. There was no association between HER2 discordance and the number of biopsy tissue fragments (p = 0.764). CONCLUSIONS: Hofmann's HER2 scoring system is a fairly reliable tool for evaluating HER2 status in biopsy and excision specimens. Discordant HER2 results in paired specimens were observed in a small percentage of gastric cancers. Testing all available specimens should be considered in order to eliminate discrepancies, especially when discordant tumor differentiation is observed.

Expression profile of microRNA-200 family in cholangiocarcinoma arising from choledochal cyst.

BACKGROUND AND AIM: The risk of cholangiocarcinoma (cCC) arising from choledochal cyst (CC-CC) is imminent, if the latter not treated appropriately in time. Epithelial-to-mesenchymal transition (EMT) is considered a critical step for various solid cancers, which is regulated by the microRNA-200 (miR-200) family. The aim of this study was to assess the role of miR-200 family in the pathogenesis of CC-CC. METHODS: Sixteen patients with CC-CC were enrolled and 254 patients with conventional cCC served as clinicopathologic controls. Fifty-four cCC were selected to compare the miR-200 family expression and immunohistochemical characteristics. Gain-and loss-of-function studies of miR-200 family were conducted using the cCC cell lines. RESULTS: CC-CC were younger (P < 0.01), more female- predominated (P < 0.01), and rarely associated with lithiasis (P < 0.01) compared with those of cCC. miR-200 family was down-regulated in CC-CC, while miR-200 family was paradoxically up-regulated in cCC (P < 0.01). CC-CC exhibited overt overexpression of mesenchymal markers including ZEB1, Twist, Snail, and vimentin as well an aberrant E-cadherin expression in comparison with cCC. In vitro migration assay showed that cCC cells bearing lower miR-200 s levels exhibited stronger migration ability. Invasive ability of cCC cells was increased after miR-200 s knockdown, accompanied by up-regulation of mesenchymal markers. CONCLUSIONS: CC-CC was characterized by distinct demographics, precipitating factors, and down-regulation of miR-200 family, compared with those of cCC. The pathogenesis of CC-CC might partly link to the silencing of miR-200 family, acting via ZEB1-directed EMT activation.

NAB2-STAT6 fusion types account for clinicopathological variations in solitary fibrous tumors.

Solitary fibrous tumor (SFT) is characterized by the inv12(q13q13)-derived NAB2-STAT6 fusion, which exhibits variable breakpoints and drives STAT6 nuclear expression. The implications of NAB2-STAT6 fusion variants in pathological features and clinical behavior remain to be characterized in a large cohort of SFTs. We investigated the clinicopathological correlates of this genetic hallmark and analyzed STAT6 immunoexpression in 28 intrathoracic, 37 extrathoracic, and 23 meningeal SFTs. These 88 tumors were designated as histologically nonmalignant in 75 cases and malignant in 13, including 1 dedifferentiated SFT. Eighty cases had formalin-fixed and/or fresh samples to extract assessable RNAs for RT-PCR assay, which revealed NAB2-STAT6 fusion variants comprising 12 types of junction breakpoints in 73 fusion-positive cases, with 65 (89%) falling into 3 major types. The predominant NAB2ex4-STAT6ex2 (n=33) showed constant breakpoints at the ends of involved exons, whereas the NAB2ex6-STAT6ex16 (n=16) and NAB2ex6-STAT6ex17 (n=16) might exhibit variable breakpoints and incorporate NAB2 or STAT6 intronic sequence. Including 73 fusion-positive and 7 CD34-negative SFTs, STAT6 distinctively labeled 87 (99%) SFTs in nuclei, exhibited diffuse reactivity in 73, but did not decorate 98 mimics tested. In seven fusion-negative cases, 6 were STAT6-positive, suggesting rare fusion variants not covered by RT-PCR assay. Regardless of histological subtypes, intrathoracic SFTs affected older patients (P=0.035) and tended to be larger in size (P=0.073). Compared with other variants, NAB2ex4-STAT6ex2/4 fusions were significantly predominant in the SFTs characterised by intrathoracic location (P<0.001), older age (P=0.005), decreased mitoses (P=0.0028), and multifocal or diffuse STAT6 staining (P=0.013), but not found to correlate with disease-free survival. Conclusively, STAT6 nuclear expression was distinctive in the vast majority of SFTs, including all fusion-positive tumors, and exploitable as a robust diagnostics of CD34-negative cases. Despite the associations of NAB2-STAT6 fusion variants with several clincopathological factors, their prognostic relevance should be further validated in large-scale prospective studies of SFTs.

Alterations of the mTOR pathway in hepatic angiomyolipoma with emphasis on the epithelioid variant and loss of heterogeneity of TSC1/TSC2.

AIMS: To determine the significance of the epithelioid type and the corresponding molecular alterations in hepatic angiomyolipoma (AML). METHODS AND RESULTS: We retrieved 24 samples of hepatic AML to delineate the clinicopathological features and the immunohistochemical expression of components in the mTOR pathway, and employed microsatellite markers to analyse allelic imbalances in the TSC1 and TSC2 regions. Myomatous AML was the most common type, and a predominantly epithelioid cell population was observed in 50% of the samples. Two-thirds of all samples contained <20% of fat tissue. Four cases of monotypic epithelioid AML were discovered without prognostic implications. Elevated phospho-p70S6 kinase expression was noted in 19 samples in the absence of phospho-AKT activity. Loss of heterogeneity (LOH) of TSC1/TSC2 was found in 15 samples. As compared wityh syndromic AML samples, sporadic AML samples showed LOH of microsatellite markers to a limited extent. Only four samples had increased ß-catenin expression in the context of concurrent high expression of phospho-p70S6 kinase and phospho-S6 (P = 0.018). CONCLUSIONS: The low fat content and epithelioid cytomorphology in hepatic AML potentially obstruct preoperative and pathological diagnosis. Alteration of the mTOR pathway and LOH of the tuberous sclerosis complex genes is a frequent pathogenesis in hepatic AMLs.

Altered T-bet dominance in IFN-γ-decoupled CD4+ T cells with attenuated cytokine storm and preserved memory in influenza.

Cytokine storm has been postulated as one of the major causes of mortality in patients with severe respiratory viral infections such as influenza. With the help of an influenza Ag- specific mouse experimental system, we report that CD4(+) T cells contribute effector cytokines leading to lung inflammation in acute influenza. Although virus can no longer be detected from tissues 14 d postinfection, virus-derived Ag continues to drive a CD4(+) T cell response after viral clearance. Ag-specific CD4(+) T cells proliferate and evolve into memory CD4(+) T cells efficiently, but the production of effector cytokines is seriously hampered during this phase. This decoupling of proliferation and effector cytokine production doesn't appear in conjunction with increased suppression by regulatory T cells or decreased induction of transcription factors. Rather, GATA-3 and ROR-γt levels are elevated when compared with cells that have effector cytokine production. T-bet dominance over GATA-3 and ROR-γt decreases with the disarmament of effector cytokine production. Importantly, upon reinfection, these decoupled cells produce elevated levels of IFN-γ and were effective in virus eradication. These results provide a mechanism through altered T-bet dominance to dampen the cytokine storm without impeding the generation of memory T cells in influenza virus infection.