Influence of Tumor Stroma on the Aggressiveness of Poorly Cohesive Gastric Carcinoma.

Tumor-stroma crosstalk promotes the adaptation of cancer cells to the local microenvironment and sustains their growth. We assessed the quantitative and qualitative impact of intralesional stroma on clinic-pathological features and the prognosis of poorly cohesive gastric cancer (PCGC) variants. Tissue microarrays including 75 PCGC specimens were immunostained for cytokeratin 8/18 and α-smooth muscle actin to assess the relative proportion of neoplastic cells versus stromal components and the cases were subsequently divided into stroma-rich (SR) and stroma-poor (SP) tumors. Stromal status is significantly associated with the depth of tumor invasion. Patient survival rate was found to be higher in the SP compared to the SR tumor group and, hence, abundant stroma was identified as a significant risk factor in univariable analysis but had no independent prognostic impact. We also investigated the mRNA levels of KRT8 and the associated transcriptional signatures using the molecular data of 82 PCGC cases divided into KRT8-high and KRT8-low groups. KRT8-high tumors were enriched in proteins localized in the extracellular compartment and their expression levels correlated with longer survival in the KRT8-high group and shorter overall survival in the KRT8-low group. Comprehensively, we find that relative intralesional stromal content is a marker of aggressiveness in PCGC tumors and that extracellular proteins characterize functionally and clinically different PCGC subgroups.

YAP Activation Is Associated with a Worse Prognosis of Poorly Cohesive Gastric Cancer.

Poorly cohesive (PC) gastric cancer (GC) is extremely aggressive in progression, and there is an urgent need to identify the molecular pathways involved. We hypothesized the essential role of the RhoA-YAP axis in these mechanisms. The present observational multicenter retrospective study included 133 patients with PC GC treated at two dedicated European surgical centers between 2004 and 2014. YAP nuclear localization was measured by immunohistochemical (IHC) analysis of tissue biopsies. The complete absence of nuclear reactivity was coded as negative expression; we considered "any positive" as low nuclear expression (>0% but <10% of cells) and high nuclear expression (≥10% of cells). Women represented about half of the present series (52%), and the median age was 64 years (p25-p75 range: 53-75). Neoadjuvant and adjuvant treatments were administered to 10% and 54% of the cases, respectively. Extended systemic lymphadenectomy (D2) was the most common (54%). In nearly all cases, the number of retrieved nodes was ≥15, i.e., adequate for tumor staging (94%). An R0 resection was achieved in 80% of the cases. Most patients were pathological T stage 3 and 4 (pT3/pT4 = 79.0%) and pathological N stage 2, 3a, and 3b (pN2/pN3a/pN3b = 47.0%) at the pathological examination. Twenty patients (15%) presented distant metastases. Five-year overall survival (OS) was significantly higher (p = 0.029) in patients with negative YAP (46%, 95% CI 31.1-60.0%) than in the other patients (27%, 17.5-38.1%). Moreover, when controlling for sex, age, pT, pN, and percentage of signet ring cells in the multivariable analysis, YAP expression was a significant predictor of OS (HR 2.03, 95% CI: 1.18-3.51, p = 0.011). Our results provide new insights into the role of the YAP signaling cascade, as its activation was associated with a worse prognosis in PC GC.

The Prognostic Role of True Radical Resection in Perihilar Cholangiocarcinoma after Improved Evaluation of Radial Margin Status.

BACKGROUND: The evaluation of surgical margins in resected perihilar cholangiocarcinoma (PHCC) remains a challenging issue. Both ductal (DM) and radial margin (RM) should be considered to define true radical resections (R0). Although DM status is routinely described in pathological reports, RM status is often overlooked. Therefore, the frequency of true R0 and its impact on survival might be biased. OBJECTIVE: To improve the evaluation of RM status and investigate the impact of true R0 on survival. METHODS: From 2014 to 2020, 90 patients underwent curative surgery for PHCC at Verona University Hospital, Verona, Italy. Both DM (proximal and distal biliary margin) and RM (hepatic, periductal, and vascular margin) status were evaluated by expert hepatobiliary pathologists. Patients with lymph-node metastases or positive surgical margins (R1) were candidates for adjuvant treatment. Clinicopathological and survival data were retrieved from an institutional database. RESULTS: True R0 were 46% (41) and overall R1 were 54% (49). RM positivity resulted in being higher than DM positivity (48% versus 27%). Overall survival was better in patients with true R0 than in patients with R1 (median survival time: 53 vs. 28 months; p = 0.016). Likewise, the best recurrence-free survival was observed in R0 compared with R1 (median survival time: 32 vs. 15 months; p = 0.006). Multivariable analysis identified residual disease status as an independent prognostic factor of both OS (p = 0.009, HR = 2.68, 95% CI = 1.27-5.63) and RFS (p = 0.009, HR = 2.14, 95% CI = 1.20-3.83). CONCLUSION: Excellent survival was observed in true R0 patients. The improved evaluation of RM status is mandatory to properly stratify prognosis and select patients for adjuvant treatment.

Landscape of Druggable Molecular Pathways Downstream of Genomic CDH1/Cadherin-1 Alterations in Gastric Cancer.

Loss of CDH1/Cadherin-1 is a common step towards the acquisition of an abnormal epithelial phenotype. In gastric cancer (GC), mutation and/or downregulation of CDH1/Cadherin-1 is recurrent in sporadic and hereditary diffuse GC type. To approach the molecular events downstream of CDH1/Cadherin-1 alterations and their relevance in gastric carcinogenesis, we queried public databases for genetic and DNA methylation data in search of molecular signatures with a still-uncertain role in the pathological mechanism of GC. In all GC subtypes, modulated genes correlating with CDH1/Cadherin-1 aberrations are associated with stem cell and epithelial-to-mesenchymal transition pathways. A higher level of genes upregulated in CDH1-mutated GC cases is associated with reduced overall survival. In the diffuse GC (DGC) subtype, genes downregulated in CDH1-mutated compared to cases with wild type CDH1/Cadherin-1 resulted in being strongly intertwined with the DREAM complex. The inverse correlation between hypermethylated CpGs and CDH1/Cadherin-1 transcription in diverse subtypes implies a common epigenetic program. We identified nonredundant protein-encoding isoforms of 22 genes among those differentially expressed in GC compared to normal stomach. These unique proteins represent potential agents involved in cell transformation and candidate therapeutic targets. Meanwhile, drug-induced and CDH1/Cadherin-1 mutation-related gene expression comparison predicts FIT, GR-127935 hydrochloride, amiodarone hydrochloride in GC and BRD-K55722623, BRD-K13169950, and AY 9944 in DGC as the most effective treatments, providing cues for the design of combined pharmacological treatments. By integrating genetic and epigenetic aspects with their expected functional outcome, we unveiled promising targets for combinatorial pharmacological treatments of GC.

Poorly Cohesive Gastric Cancers Showing the Transcriptomic Hallmarks of Epithelial-Mesenchymal Transition Behave Aggressively.

HYPOTHESIS: Poorly cohesive (PC) gastric cancer (GC) exhibits variable clinical behavior, being extremely aggressive in most cases but more indolent at times. We hypothesized that the integrative genomic and gene expression characterization of a PC GC series could help identifying molecular subtypes with potential clinical implications. MATERIALS AND METHODS: 64 PC GCs were assessed for alterations in 409 genes and 30 cases were subjected to transcriptomic profiling of 20,815 genes. RESULTS: A median of 8.2 mutations per Mb (interquartile range 6.9-10.4) was found and a tumor mutational load >10 muts/Mb was significantly associated with patients' worse survival ( P =0.0024). The most frequent mutated genes were CDH1 and TP53 (each 32.8%) followed by PIK3CA (10.9%). In 15 samples (23.4%), at least 1 chromatin remodeling gene was mutated: KMT2D (5 cases); ARID1A and BAP1 (4 cases each); EZH2 , KMT2A , PBRM1 (1 case each). Eight samples (12.5%) had fusion genes involving CLDN18 gene. Gene expression profiling identified 4 different clusters: cluster A associated with epithelial to mesenchymal transition (EMT) signature; cluster B associated to proliferative signature and EMT; cluster C correlated to hedgehog signaling; cluster D showing no enrichment for any of the previous signatures. Notably, cluster A and B showed a worse prognosis compared with clusters C and D ( P =0.0095). CONCLUSION: integrated genomic and transcriptomic analysis suggest the existence of 4 molecular subtypes of PC GC with prognostic significance where EMT features are associated with a worse outcome.

The LIver SEntinel LYmph-node (LISELY) study: A prospective intraoperative real time evaluation of liver lymphatic drainage and sentinel lymph-node using near-infrared (NIR) imaging with Indocyanine Green (ICG).

Near-infrared (NIR) imaging with Indocyanine green (ICG) has been recently proposed for the sentinel lymph node (SLN) and lymphatic out-flow detection in several tumors. Nowadays its application in primary and secondary liver (LCs) and biliary cancers (BTCs) remains uninvestigated. A proof-of-concept prospective observational study including 18 patients underwent surgery for LCs and BTCs from September 2021 to November 2021 was carried out. The intraoperative NIR imaging with ICG was detected at predefined temporary intervals in order to identify the main lymphatic out-flow and the SLN. In 14 patients (77.8%) the lymphatic outflow pathway was visualized with a median time of 3 min after ICG injection (IQR 3-10). The SLN was detected and confirmed at the histological examination in 12 patients (66.7%). Intraoperative NIR imaging with ICG is a safe and feasible method to identify the lymphatic out-flow and SLN in LCs and BTCs.

Ileal Crohn's Disease Exhibits Similar Transmural Fibrosis Irrespective of Phenotype.

INTRODUCTION: In Crohn's disease (CD), the assessment of transmural inflammation and fibrosis is of utmost importance. This study aimed to quantify these parameters in CD ileal specimens and correlate them with disease progression. METHODS: This is a retrospective unicentric study based on the analysis of archived specimens (n = 103) of primary ileal resection. Data were retrieved from a prospective national inflammatory bowel disease registry. Two pathologists, blinded for CD phenotype and clinical indications for surgery, examined 3 sections per patient and graded inflammation and fibrosis, based on a histopathological score. RESULTS: Penetrating (B3, n = 74) CD exhibited significantly higher inflammation in diseased areas, compared with stricturing (B2, n = 29) disease (score 3: 96% vs 76%, P = 0.005 in inflamed areas; 78% vs 55%, P = 0.019 in most affected areas). This was also observed for the comparison of B2 CD with B3 CD with (B3s, n = 54) and without associated stricture (B3o, n = 20): B3s vs B2: 81% vs 55%, P = 0.033 in most affected areas; B3o vs B2: 100% vs 76%, P = 0.006 in inflamed areas; 70% vs 55%, P = 0.039 in most affected areas. We could not show differences in fibrosis scores between the subphenotypes. Postoperative new penetrating events occurred only in B3s (n = 6, 11%, P = 0.043) patients. The changing of biologic therapy after surgery correlated with severe inflammation at the proximal ileal margin (55% changed vs 25% not changed, P = 0.035). DISCUSSION: In our cohort, fibrosis scores and fibromuscular changes were comparable, irrespective of CD phenotype. Inflammation severity was the major differentiator between penetrating and stricturing disease.JOURNAL/cltg/04.03/01720094-202104000-00012/inline-graphic1/v/2021-04-13T161901Z/r/image-tiff.

Personalized therapeutic strategies in HER2-driven gastric cancer.

BACKGROUND: Trastuzumab is the only approved targeted therapy in patients with HER2-amplified metastatic gastric cancer (GC). Regrettably, in clinical practice, only a fraction of them achieves long-term benefit from trastuzumab-based upfront strategy. To advance precision oncology, we investigated the therapeutic efficacy of different HER2-targeted strategies, in HER2 "hyper"-amplified (≥ 8 copies) tumors. METHODS: We undertook a prospective evaluation of HER2 targeting with monoclonal antibodies, tyrosine kinase inhibitors and antibody-drug conjugates, in a selected subgroup of HER2 "hyper"-amplified gastric patient-derived xenografts (PDXs), through the design of ad hoc preclinical trials. RESULTS: Despite the high level of HER2 amplification, trastuzumab elicited a partial response only in 2 out of 8 PDX models. The dual-HER2 blockade with trastuzumab plus either pertuzumab or lapatinib led to complete and durable responses in 5 (62.5%) out of 8 models, including one tumor bearing a concomitant HER2 mutation. In a resistant PDX harboring KRAS amplification, the novel antibody-drug conjugate trastuzumab deruxtecan (but not trastuzumab emtansine) overcame KRAS-mediated resistance. We also identified a HGF-mediated non-cell-autonomous mechanism of secondary resistance to anti-HER2 drugs, responsive to MET co-targeting. CONCLUSION: These preclinical randomized trials clearly indicate that in HER2-driven gastric tumors, a boosted HER2 therapeutic blockade is required for optimal efficacy, leading to complete and durable responses in most of the cases. Our results suggest that a selected subpopulation of HER2-"hyper"-amplified GC patients could strongly benefit from this strategy. Despite the negative results of clinical trials, the dual blockade should be reconsidered for patients with clearly HER2-addicted cancers.

Expression of Thomsen-Friedenreich Antigen in Colorectal Cancer and Association with Microsatellite Instability.

Microsatellite instability (MSI) is a molecular phenotype due to a deficient DNA mismatch repair (dMMR). In colorectal cancer (CRC), dMMR/MSI is associated with several clinical and histopathological features, influences prognosis, and is a predictive factor of response to therapy. In daily practice, dMMR/MSI profiles are identified by immunohistochemistry and/or multiplex PCR. The Thomsen-Friedenreich (TF) antigen was previously found to be a potential single marker to identify MSI-high gastric cancers. Therefore, in this study, we aimed to disclose a possible association between TF expression and MSI status in CRC. Furthermore, we evaluated the relationship between TF expression and other clinicopathological features, including patient survival. We evaluated the expression of the TF antigen in a cohort of 25 MSI-high and 71 microsatellite stable (MSS) CRCs. No association was observed between the expression of the TF antigen and MSI-high status in CRC. The survival analysis revealed that patients with MSI-high CRC showed improved survival when the TF antigen was expressed. This finding holds promise as it indicates the potential use of the TF antigen as a biomarker of better prognosis in MSI-high CRCs that should be validated in an independent and larger CRC cohort.

Thyroid Fine-Needle Aspiration Cytology: Focusing on Adherence to Guidelines and Hospital Organization.

BACKGROUND The complications of fine-needle aspiration cytology (FNAC) are rare but can be challenging for performing physicians to diagnose and manage. This type of procedure is perceived as routine and devoid of substantial risks, but uncommon complications can occur and need to be addressed with careful workup. CASE REPORT A FNAC procedure for a young female patient with multiple thyroid nodules was requested by her general practitioner. After the FNAC thyroid procedure, a carotid wall hematoma was suspected and could not be excluded with ultrasound (US) alone. Thus, the patient underwent a computed tomography angiogram (CTA) that excluded blood extravasation from the carotid, confirming the suspicion of perivascular blood accumulation. As a precaution, the patient was hospitalized, with US follow-up; she was dismissed the day after her hospital admission with a diagnosis of a benign thyroid nodule in multinodular goiter according to SIAPEC-IAP classification. CONCLUSIONS This case highlights how a routine-perceived procedure such as FNAC could present a challenge to the performing physicians, pathologist, and radiologist, raising the suspicion of a severe complication that needs to be addressed with a readily available emergency service that may be accessible only within a central hospital-level organization. This case reinforces the point that more careful adherence to clinic-radiological guidelines is needed to avoid potentially inappropriate and harmful procedures. A review of the literature concerning guidelines for FNAC procedure, diagnostic classifications, and reported complications is provided as part of this case report.

The amount of signet ring cells is significantly associated with tumour stage and survival in gastric poorly cohesive tumours.

BACKGROUND AND OBJECTIVES: The aim of this study was to evaluate whether the amount of signet ring cells (SRCs) affects clinicopathological characteristics and prognosis of poorly cohesive (PC) gastric tumours. STUDY DESIGN: One hundred seventy-three patients with PC tumours treated at three European centres from 2004 to 2014 were reclassified in three categories: (a) pure SRC cancers (SRC1) (≥90% SRCs); (b) PC carcinoma with SRC component (SRC2) (>10%, <90% SRCs); (c) PC carcinoma not otherwise specified (SRC3) (≤10% SRCs). RESULTS: The percentage of SRCs was inversely related to the pT stage (Spearman's ρ = -0.174, P < .001) and the number of positive nodes coded as a continuous variable (P = .009). Five year cancer-related survival was significantly higher (58%, 95% confidence interval [CI]: 36%-75%) in SRC1 compared with SRC2 (39%, 95% CI: 28%-50%) and SRC3 (38%, 95% CI: 22%-53%), (P = .048). In multivariable analysis, the impact of PC categories on cancer-related survival was significant when controlling for sex, age, pT, pN, and curativity (hazard ratio [HR] of sSRC2 vs SRC1 = 2.08, 95% CI: 1.01-4.29, P = .046; HR of SRC3 vs SRC1 = 2.38, 95% CI: 1.05-5.41, P = .039). CONCLUSION: The percentage of SRCs was inversely related to tumour aggressiveness, with long-term survival significantly higher in SRC1 compared with SRC2 and SRC3 tumours.

A Case Report of Insulinoma Relapse on Background Nesidioblastosis: A Rare Cause of Adult Hypoglycemia.

Context: Nesidioblastosis is a rare cause of adult hypoglycemia. Current medical therapy can mitigate disease symptoms. However, side effects and limited efficacy may prevent long-term disease management. Case Description: A 63-year-old white woman presented at our institution on April 2017 with a history of distal spleno-pancreatectomy for well-differentiated insulinoma in 2013. Hypoglycemic events did not resolve after surgery, and residual nesidioblastosis near the pancreatic resection margins was identified. Hypoglycemic episodes increased in frequency and severity despite high-dose diazoxide (DZX) therapy. On April 2016, octreotide was introduced but soon discontinued for inefficacy. When the patient arrived at our attention, add-on pasireotide was started and glucose levels monitored by subcutaneous sensor. Compared with DZX, 225 mg/d alone, sensor glucose during pasireotide + DZX 75 mg/d showed occurrence of severe hypoglycemia. Pasireotide was discontinued, and the instrumental workup (68Ga-DOTATOC CT/positron emission tomography, 99mTc-nanocolloid scintigraphy and echo-endoscopy + fine-needle aspiration biopsy) identified an insulinoma relapse. Subtotal pancreatectomy was performed without further recurrence of hypoglycemia over 9 months of follow-up. Conclusions: Although insulinoma relapses on background nesidioblastosis rarely occur, they should be considered as an alternate diagnosis when medical therapy fails to prevent hypoglycemia. Further studies are warranted to test whether the immunophenotypic signature of nesidioblastosis/insulinoma may provide insights for a tailored use of pasireotide.