VE1 immunohistochemistry predicts BRAF V600E mutation status and clinical outcome in colorectal cancer

Aim

VE1 is a monoclonal antibody detecting mutant BRAF^V600E protein by immunohistochemistry. Here we aim to determine the inter-observer agreement and concordance of VE1 with mutational status, investigate heterogeneity in colorectal cancers and metastases and determine the prognostic effect of VE1 in colorectal cancer patients.

Methods

Concordance of VE1 with mutational status and inter-observer agreement were tested on a pilot cohort of colorectal cancers (n = 34), melanomas (n = 23) and thyroid cancers (n = 8). Two prognostic cohorts were evaluated (n = 259, Cohort 1 and n = 226, Cohort 2) by multiple-punch tissue microarrays. VE1 staining on preoperative biopsies (n = 118 patients) was compared to expression in resections. Primary tumors and metastases from 13 patients were tested for VE1 heterogeneity using a tissue microarray generated from all available blocks (n = 100 blocks).

Results

Inter-observer agreement was 100% (kappa = 1.0). Concordance between VE1 and V600E mutation was 98.5%. Cohort 1: VE1 positivity (seen in 13.5%) was associated with older age (p = 0.0175) and MLH1 deficiency (p < 0.0001). Cohort 2: VE1 positivity (seen in 12.8%) was associated with female gender (p = 0.0016), right-sided tumor location (p < 0.0001), higher tumor grade (p < 0.0001) and mismatch repair (MMR)-deficiency (p < 0.0001). In survival analysis, MMR status and postoperative therapy were identified as possible confounding factors. Adjusting for these features, VE1 was an unfavorable prognostic factor. Preoperative biopsy staining matched resections in all cases except one. No heterogeneity was found across any primary/metastatic tumor blocks.

Conclusion

VE1 is highly concordant for V600E and homogeneously expressed suggesting staining can be analysed on resection specimens, preoperative biopsies, metastatic lesions and tissue microarrays.     

Incidence of Root Resorption after the Replantation of Avulsed Teeth: A Meta-analysis

Introduction

An avulsion injury is a serious trauma to pulp and periodontal tissues. After avulsion and replantation, teeth are at risk of infection and root resorption, which may affect treatment outcome and survival rate. Thus, the purpose of this systematic review was to evaluate the incidence of root resorption after the replantation of avulsed teeth.

Efficacy of phosphatidylinositol‐3 kinase inhibitors with diverse isoform selectivity profiles for inhibiting the survival of chronic lymphocytic leukemia cells

Pharmacological inhibition of phosphatiylinositide‐3‐kinase (PI3K)‐mediated signaling holds great promise for treating chronic lymphocytic leukemia (CLL). Therefore we assessed three structurally related PI3K inhibitors targeting the PI3K‐δ isoform for their ability to inhibit the survival of freshly isolated CLL cells. The purely PI3K‐δ‐selective inhibitor idelalisib was compared to copanlisib (BAY 80‐6946) and duvelisib (IPI‐145), with isoform target profiles that additionally include PI3K‐α or PI3K‐γ, respectively. The concentrations leading to half‐maximal reduction of the survival of CLL cells were more than ten‐fold lower for copanlisib than for idelalisib and duvelisib. At concentrations reflecting the biological availability of the different inhibitors, high levels of apoptotic response among CLL samples were attained more consistently with copanlisib than with idelalisib. Copanlisib selectively reduced the survival of CLL cells compared to T cells and to B cells from healthy donors. In addition copanlisib and duvelisib impaired the migration of CLL cells towards CXCL12 to a greater extent than equimolar idelalisib. Similarly copanlisib and duvelisib reduced the survival of CLL cells in co‐cultures with the bone marrow stroma cell line HS‐5 more strongly than idelalisib. Survival inhibition by copanlisib and idelalisib was enhanced by the monoclonal CD20 antibodies rituximab and obinutuzumab (GA101), while antibody‐dependent cellular cytotoxicity mediated by alemtuzumab and peripheral blood mononuclear cells was not substantially impaired by both PI3K inhibitors for the CLL‐derived JVM‐3 cell line as target cells. Taken together, targeting the α‐ and δ‐ p110 isoforms with copanlisib may be a useful strategy for the treatment of CLL and warrants further clinical investigation.     

Percutaneous stereotactic radiofrequency ablation of colorectal liver metastases

Objectives  

To evaluate the outcome of patients with colorectal liver metastasis (CRLM) treated with stereotactic radiofrequency ablation (SRFA).     

Damage of the Endothelial Glycocalyx in Dialysis Patients

Damage to the endothelial glycocalyx, which helps maintain vascular homeostasis, heightens the sensitivity of the vasculature to atherogenic stimuli. Patients with renal failure have endothelial dysfunction and increased risk for cardiovascular morbidity and mortality, but the state of the endothelial glycocalyx in these patients is unknown. Here, we used Sidestream Darkfield imaging to detect changes in glycocalyx dimension in dialysis patients and healthy controls from in vivo recordings of the sublingual microcirculation. Dialysis patients had increased perfused boundary region and perfused diameters, consistent with deeper penetration of erythrocytes into glycocalyx, indicating a loss of glycocalyx barrier properties. These patients also had higher serum levels of the glycocalyx constituents hyaluronan and syndecan-1 and increased hyaluronidase activity, suggesting the shedding of these components. Loss of residual renal function had no influence on the imaging parameters but did associate with greater shedding of hyaluronan in blood. Furthermore, patients with higher levels of inflammation had more significant damage to the glycocalyx barrier. In conclusion, these data suggest that dialysis patients have an impaired glycocalyx barrier and shed its constituents into blood, likely contributing to the sustained endothelial cell activation observed in ESRD.Patients with chronic renal failure have endothelial dysfunction and accelerated vascular disease leading to increased morbidity and mortality as a result of cardiovascular events.^1–4 The mechanisms responsible are unclear, controversial, and presumed to be multifactorial. The vascular endothelium is coated on the luminal side by the glycocalyx, a negatively charged mesh of proteoglycans (PGs) and associated glycosaminoglycans.⁵ It is involved in mediating shear-induced release of nitric oxide and contributes to the endothelial permeability barrier, the regulation of redox state, and the inhibition of coagulation as well as leukocyte and platelet adhesion.^6–9 Perturbation of glycocalyx occurs after provocation with inflammatory or atherogenic stimuli (such as ischemia reperfusion,¹⁰ infusion of oxidized LDL,^9,11 administration of TNF-α¹² or endotoxin,¹³ and during hyperglycemia¹⁴) and after stimulation with thrombin,¹⁵ atrial natriuretic peptide,¹⁶ or abnormal blood shear stress.^17,18 Consequences of glycocalyx perturbation include a wide range of vascular abnormalities in experimental models, including increased vascular permeability followed by generation of tissue edema,¹⁹ increased rolling and adhesion of leukocytes,⁶ and increased platelet adhesion.⁹ Therefore, disruption of the glycocalyx leads to enhanced sensitivity of vasculature to atherogenic stimuli. Based on these observations, the importance of integrity of the endothelial glycocalyx in vascular homeostasis has become evident.Attempts to assess the impairment of endothelial function in vivo are a challenge given the multifunctional nature of endothelial cells and lack of standardized tools to noninvasively assess endothelial function in a patient-friendly manner. We recently developed an imaging-based method to detect changes in glycocalyx dimension from in vivo recordings of the sublingual microcirculation, enabling us to assess the microvascular glycocalyx in vivo in patients. Previous studies have shown that, in healthy volunteers, the glycocalyx is disrupted by acute hyperglycemia.¹⁴ Subsequently, a significant reduction in glycocalyx volume was found in patients with type 1 diabetes.²⁰ This disruption may contribute to the known predisposition of these patients to vascular disease.No data are available on the state of the endothelial glycocalyx in patients with chronic renal failure. However, it is reasonable to hypothesize that the endothelial glycocalyx is affected in these patients given their predisposition to endothelial dysfunction and vascular disease. A damaged glycocalyx may lead to increased vulnerability and susceptibility of endothelial cells to vascular risk factors present in uremia. Therefore, the objective of this study was to answer the following questions. (1) Is the microvascular endothelial glycocalyx damaged in patients with ESRD on both hemodialysis (HD) and peritoneal dialysis (PD) compared with age- and sex-matched healthy controls? (2) Do dialysis patients have increased serum concentrations of glycocalyx constituents reflecting increased shedding? (3) Do the changes in endothelial glycocalyx correlate with other serum markers of endothelial activation, like sE-selectin?     

Tumor Budding is an Independent Predictor of Outcome in AJCC/UICC Stage II Colorectal Cancer

Background

In colorectal cancer, the morphology of the invasive tumor margin may reflect aggressiveness of tumor growth, thus providing important prognostic information. The tumor growth pattern according to Jass and the extent of tumor budding were analyzed in patients with American Joint Committee on Cancer/Union for International Cancer Control (AJCC/UICC) stage II disease.

Methods

Tumors of 120 randomly selected patients with AJCC/UICC stage II disease were retrospectively reviewed for tumor growth pattern (expanding vs. infiltrating) and the extent of tumor budding, with high-grade budding reflecting presence of 10 or more budding foci scattered at the invasive tumor margin. Progression-free and cancer-specific survivals were determined by the Kaplan?CMeier method. For multivariable analysis, Cox??s proportional hazards regression models were performed.

Results

The infiltrating growth pattern was significantly associated with histological subtype and lymphovascular invasion, while high-grade budding was significantly associated with tumor grade and lymphovascular invasion. High-grade budding, but not the infiltrating growth pattern, was significantly associated with outcome in univariable analysis. Cox??s proportional hazards regression models proved tumor budding to be an independent predictor of disease progression (hazard ratio 3.91, 95?% confidence interval 1.3?C11.77; P?=?0.02) and cancer-related death (hazard ratio 5.90, 95?% confidence interval 1.62?C21.51; P?=?0.007). The combination of infiltrating growth pattern and high-grade budding did not have a stronger prognostic significance than tumor budding alone.

Conclusions

Tumor budding independently predicted patient outcome in patients with AJCC/UICC stage II colorectal cancer and may therefore be used for accurate prognostication, patient counseling, and design of clinical trials by using integrated multimodal therapy.