Thymic Imaging Pitfalls and Strategies for Optimized Diagnosis

Thymic imaging is challenging because the imaging appearance of a variety of benign and malignant thymic conditions are similar. CT is the most commonly used modality for mediastinal imaging, while MRI and fluorine 18 fluorodeoxyglucose (FDG) PET/CT are helpful when they are tailored to the correct indication. Each of these imaging modalities has limitations and technical pitfalls that may lead to an incorrect diagnosis and mismanagement. CT may not be sufficient for the characterization of cystic thymic processes and differentiation between thymic hyperplasia and thymic tumors. MRI can be used to overcome these limitations but is subject to other potential pitfalls such as an equivocal decrease in signal intensity at chemical shift imaging, size limitations, unusual signal intensity for cysts, subtraction artifacts, pseudonodularity on T2-weighted MR images, early imaging misinterpretation, flow and spatial resolution issues hampering assessment of local invasion, and the overlap of apparent diffusion coefficients between malignant and benign thymic entities. FDG PET/CT is not routinely indicated due to some overlap in FDG uptake between thymomas and benign thymic processes. However, it is useful for staging and follow-up of aggressive tumors (eg, thymic carcinoma), particularly for detection of occult metastatic disease. Pitfalls in imaging after treatment of thymic malignancies relate to technical challenges such as postthymectomy sternotomy streak metal artifacts, differentiation of postsurgical thymic bed changes from tumor recurrence, or human error with typical "blind spots" for identification of metastatic disease. Understanding these pitfalls enables appropriate selection of imaging modalities, improves diagnostic accuracy, and guides patient treatment. ©RSNA, 2024 Test Your Knowledge questions for this article are available in the supplemental material.

Effects of EGFR driver mutations on pathologic regression in resectable locally advanced non-small cell lung cancer treated with neoadjuvant chemoradiation and completion surgery

OBJECTIVE

We hypothesized that driver mutations in epidermal growth factor receptor (EGFR) are associated with decreased pathologic response to neoadjuvant chemoradiation (NA-ChRT) in locally advanced non-small cell lung cancer (LA-NSCLC).

METHODS

Patients with Stage IIB-IIIA NSCLC treated with NA-ChRT, completion surgery, and underwent molecular profile testing were identified in a lung cancer database. Pathologic response was quantified using: (i) major pathologic response (MPR), (ii) complete pathologic response (pCR), and (iii) mean residual viable tumor cells (MRTC). Two groups were formed based on the presence or absence of driver mutations. Clinical and pathological correlations between the groups were studied.

RESULTS

Forty-seven patients underwent tumor molecular profile testing, NA-ChRT, and completion surgery. Compared to the no-driver mutation group, the driver mutation group had lower MPR (23% vs 71%, p = 0.003), pCR (0% vs 26%, p = 0.02), and higher MRTC (43.4% vs 15.8%, p = 0.009). Univariate analysis showed an increased MPR rate for smokers, squamous cell histology, ChRT-surgery interval >65 days, and no-driver mutations. Multivariate analysis showed that only no-driver mutations (OR 0.39, p = 0.02) remained significant for MPR. PD-L1 status did not affect MPR. At 2 years, the driver mutation group had lower rates of local control (Hazard ration [HR] 0.67, p = 0.17) and disease-free survival (HR 0.5, p = 0.001). Overall survival was similar for both groups (HR = 1.04, p = 0.86).

CONCLUSION

Following 60 Gray NA-ChRT, tumors with a driver mutation had lower MPR and pCR rates than tumors without a driver mutation. PD-L1 was not associated with tumor regression.

ADVANCES IN KNOWLEDGE

Patients with resectable LA-NSCLC and an EGFR driver mutation treated with neoadjuvant-ChRT and completion surgery have reduced pathologic regression, lower local control rates, and shorter disease-free survival than patients without a driver mutation. Evaluation of molecular testing should be introduced in LA-NSCLC intended for prognostication and treatment decisions.

Effect of pharmacological heart failure drugs and gene therapy on Danon's cardiomyopathy

Danon disease is a rare X-linked genetic disease resulting from LAMP2 mutations leading to defective lysosomal function. Heart failure is the main causes of morbidity and mortality. Mice with an LAMP2-exon-6-deletion (L2Δ6), develop cardiac hypertrophy followed by dilated cardiomyopathy, in association with accumulation of autophagosomes, fibrosis and oxidative stress. We investigated the effect of drugs used to treat heart failure and of LAMP2 gene therapy on the phenotype, molecular markers and ROS in LAMP2 cardiomyopathy. L2Δ6 mice were treated with Angiotensin II, Ramipril, Metoprolol or Spironolactone. Gene therapy was delivered by IP injection of Adeno-associated-virus (AAV9) -LAMP2 vector to neonates ("AAVLAMP2-Prevention"), or at 15 weeks of age ("AAVLAMP2-Treatment"). Angiotensin II markedly aggravated the cardiac phenotype. Ramipril and Spironolactone were effective in attenuating left ventricular hypertrophy and preserving the systolic function. Cardiac protection was associated with decreased autophagosome accumulation, reduced fibrosis and oxidative stress. Gene therapy effectively attenuated autophagosome accumulation and ROS in L2Δ6 hearts, lowering troponin release to nearly normal levels. AAVLAMP2-Prevention protected against systolic dysfunction and decreased hypertrophy. AAVLAMP2-Treatment prevented ventricular dilatation and dysfunction but had no effect on wall thickness. We conclude that RAAS inhibitors are highly effective against cardiomyopathy progression in an experimental mouse model of Danon's and shall be considered in human patients for this purpose until novel therapies become clinically available.

Abstract CT154: B-cell infiltration in lung cancer predicts response to neoadjuvant pembrolizumab

Background Neoadjuvant immune checkpoint inhibitor treatment is a promising approach for resectable cancer, including non-small cell lung cancer (NSCLC). The characteristics of potential responders to such treatments and the molecular underlying events are not known. Methods We have conducted a phase I, investigator-initiated single-center study (MK3457-223), to examine the safety of neoadjuvant pembrolizumab for stage I-II resectable NSCLC and to determine the recommended phase II dose/schedule (RP2D/S). FFPE biopsies and surgical specimens were subjected to correlative studies. NanoString’s GeoMx Digital Spatial Profiler (DSP) analysis was conducted on pre-treatment samples and post-treatment responder samples. Protein (72 proteins) and mRNA expression data (73 genes) analysis was conducted on regions of interest (ROIs), defined as mostly CD8 positive or mostly pan-cytokeratin positive (presumed cancer cells). Pathology assessment was done on the surgical specimen to identify major pathologic response (MPR; ≤10% remaining viable cells). Statistical analysis was done to compare responders (MPR+) to non-responders (MPR-) by Mann Whitney with false discovery rate correction. Immunohistochemistry (IHC) was conducted on post-treatment samples. Results Twenty-six patients initiated treatment on the study. Two patients (8%, 95% C.I 0-18%) had adverse events that precluded surgery, 1 patient refused surgery after treatment. 7 patients (27%, 95% C.I 10-44%) achieved a major pathologic response (MPR; responders), 3 patients (12%, 95% C.I 0-24%) achieved complete pathologic response. Responders had a longer interval from treatment to surgery (43 days vs. 36 days, univariate analysis, p-value 0.043). RP2D/S was determined as 2 treatments of 200mg pembrolizumab at 3 week interval, followed by surgery at least 2 weeks later. The expression of several proteins and genes differed between responders and non-responders. Pre-treatment, CD20 protein was the most differentially expressed protein both in in CD8+ (4.7 fold, p=0.002) and in cancer cells (4.8 fold, p=0.001) ROIs, in both cases higher in the responders compared to the non-responders. Comparing pre to post-treatment expression in responding tumors, the protein found to be upregulated to the highest extent following pembrolizumab treatment was CD20 protein (6.2-fold, p=0.001), as was its encoding gene, MS4A1 (2.4-fold, p=0.006). CD20 IHC of post-treatment samples demonstrated tertiary lymphoid structures (TLS) to be more prevalent in responders compared to non-responders (3.2-fold, p<0.05). Conclusions Longer interval from treatment to surgery was associated with higher rate of MPR. Presence of tumor-infiltrating B-cells and evolvement of TLSs was strongly correlated with pathologic response to neoadjuvant pembrolizumab in early stage NSCLC.

Citation Format: Jair Bar, Iris Kamer, Oranit Zadok, Damien Urban, Marina Perelman, Ilanit Redinsky, Aliza Ackerstein, Sameh Daher, Efrat Ofek, Amir Onn, Nona Zeitlin, Alon Ben-Nun, Ran Kremer, Inbal Daniel, Yossef Glantzspiegel, Irit Gat-Viks. B-cell infiltration in lung cancer predicts response to neoadjuvant pembrolizumab [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr CT154.

Soluble HLA peptidome of pleural effusions is a valuable source for tumor antigens

Background

Soluble human leucocyte antigen (sHLA) molecules, released into the plasma, carry their original peptide cargo and provide insight into the protein synthesis and degradation schemes of their source cells and tissues. Other body fluids, such as pleural effusions, may also contain sHLA-peptide complexes, and can potentially serve as a source of tumor antigens since these fluids are drained from the tumor microenvironment. We explored this possibility by developing a methodology for purifying and analyzing large pleural effusion sHLA class I peptidomes of patients with malignancies or benign diseases.

Methods

Cleared pleural fluids, cell pellets present in the pleural effusions, and the primary tumor cells cultured from cancer patients’ effusions, were used for immunoaffinity purification of the HLA molecules. The recovered HLA peptides were analyzed by liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) and the resulting LC-MS/MS data were analyzed with the MaxQuant software tool. Selected tumor antigen peptides were tested for their immunogenicity potential with donor peripheral blood mononuclear cells (PBMCs) in an in vitro assay.

Results

Mass spectrometry analysis of the pleural effusions revealed 39,669 peptides attributable to 11,305 source proteins. The majority of peptides identified from the pleural effusions were defined as HLA ligands that fit the patients’ HLA consensus sequence motifs. The membranal and soluble HLA peptidomes of each individual patient correlated to each other. Additionally, soluble HLA peptidomes from the same patient, obtained at different visits to the clinic, were highly similar. Compared with benign effusions, the soluble HLA peptidomes of malignant pleural effusions were larger and included HLA peptides derived from known tumor-associated antigens, including cancer/testis antigens, lung-related proteins, and vascular endothelial growth factor pathway proteins. Selected tumor-associated antigens that were identified by the immunopeptidomics were able to successfully prime CD8⁺ T cells.

Conclusions

Pleural effusions contain sHLA-peptide complexes, and the pleural effusion HLA peptidome of patients with malignant tumors can serve as a rich source of biomarkers for tumor diagnosis and potential candidates for personalized immunotherapy.

Pleuritis due to Mycobacterium xenopi without pulmonary infection

Nontuberculous mycobacteria (NTM) may cause pulmonary and extra-pulmonary disease in both immunocompetent and immunocompromised patients. Pleuritis is an uncommon manifestation on NTM disease, and pleuritis caused by Mycobacterium xenopi has only been described once before. Because it is considered to be an environmental contaminant, isolation of M. xenopi from bronchopulmonary secretions or other sites is often dismissed. The disease caused by M. xenopi is usually a pulmonary infection and typically occurs in severely immunocompromised individuals or in immunocompetent patients with an underlying chronic lung disease. We describe an unusual case of pleuritis caused by M. xenopi in a patient without an underlying chronic lung disease and with no evidence of a concurrent M. xenopi pulmonary infection.

Predicting response to pembrolizumab in non-small cell lung cancer, by analyzing the spatial arrangement of tumor infiltrating lymphocytes using deep learning

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Background: Immune checkpoint inhibitors (ICI) have become the standard treatment for metastatic NSCLC, although only a small proportion of patients derive durable benefit. PDL1 expression is the only approved biomarker to select NSCLC patients for treatment with single-agent pembrolizumab, however its predictive value is limited and better predictive biomarkers are needed. The spatial arrangement of immune cells in the tumor microenvironment (TME), namely tumor infiltrating lymphocytes (TILs), emerges as a potential biomarker for ICI efficacy. In this work, we utilized deep-learning (DL) models to extract TME features from digitized H&E slides and evaluated their predictive and prognostic role in patients with mNSCLC treated with Pembrolizumab. Methods: NSCLC patients (n=90) treated with single-agent 1st line pembrolizumab in two centers were identified. 47 patients from one center were used to train the model, and 43 patients from another center were used for validating the model. Pre-treatment H&E whole slide images (WSI) were analyzed using a deep-learning model to identify and classify tumor cells, TILs, tumor and stromal areas, and spatial features were calculated. Spatial features were correlated with clinical outcome data to train a binary classifier that identifies patients with a favorable clinical outcome. The resulting classifier combined three spatial features and three clinical features. The classifier was then applied to the validation set and differences in duration of treatment (DOT), and overall survival (OS) between patients with positive and negative scores were assessed. Results: The classifier identified patients in the validation set to have either positive (n=18) or negative (n=25) scores. Baseline patient characteristics and PDL1 score were similar between the positive and negative groups. In a Kaplan-Meier (KM) analysis, OS was significantly higher in patients with a positive score compared to patients with a negative score (HR=0.35, 95% CI 0.13-0.98; p<0.05). Positive patients had a significantly higher median OS (NR vs.17.8m, p<0.05) and 2-year OS (70.8% vs. 33%, p=0.02) than negative patients. Median DOT was also higher in positive patients compared to negative patients (10.1m vs. 6.5m). Conclusions: Deep-learning models that analyze the TME from H&E whole-slide images can identify NSCLC patients with durable benefit on Pembrolizumab. Identifying NSCLC patients who are exceptionally sensitive to anti-PD-1 therapy as monotherapy may improve clinical decision making and spare patients the unnecessary adverse effects associated with the addition chemotherapy or another IO agent.

Mesencephalic astrocyte-derived neurotrophic factor is secreted from interferon-γ-activated tumor cells through ER calcium depletion

The most successful immunotherapeutic agents are blocking antibodies to either programmed cell death-1 (PD-1), an inhibitory receptor expressed on T lymphocytes, or to its ligand, programmed cell death-ligand 1 (PD-L1). Nevertheless, many patients do not respond, and additional approaches, specifically blocking other inhibitory receptors on T cells, are being explored. Importantly, the source of the ligands for these receptors are often the tumor cells. Indeed, cancer cells express high levels of PD-L1 upon stimulation with interferon-γ (IFN-γ), a major cytokine in the tumor microenvironment. The increase in PD-L1 expression serves as a negative feedback towards the immune system, and allows the tumor to evade the attack of immune cells. A potential novel immunoregulator is mesencephalic astrocyte-derived neurotrophic factor (MANF), an endoplasmic reticulum (ER)-resident protein that is secreted from pancreatic beta cells upon cytokines activation, and can induce an alternatively activated macrophage phenotype (M2), and thus may support tumor growth. While MANF was shown to be secreted from pancreatic beta cells, its IFN-γ-induced secretion from tumor cells has never been assessed. Here we found that IFN-γ induced MANF secretion from diverse tumor cell-lines-melanoma cells, colon carcinoma cells and hepatoma cells. Mechanistically, there was no increase in MANF RNA or intracellular protein levels upon IFN-γ stimulation. However, IFN-γ induced ER calcium depletion, which was necessary for MANF secretion, as Dantrolene, an inhibitor of ER calcium release, prevented its secretion. Thus, MANF is secreted from IFN-γ-stimulated tumor cells, and further studies are required to assess its potential as a drug target for cancer immunotherapy.

Immunotherapy response modeling by ex-vivo organ culture for lung cancer

One of the major hurdles for the advancement of cancer immunotherapy is lack of robust, accessible experimental models. We aimed to produce an ex-vivo organ culture (EVOC) model of immunotherapy for non-small cell lung cancer (NSCLC). Freshly resected early stage tumors were collected from the operating room, fragmented to clusters < 450 µm and cultured with fetal calf serum and human autologous serum. The resulting EVOC includes cancer epithelial cells within tumor tissue clusters and immune cells. Original tissue features are reflected in the EVOCs. The response to immune checkpoint inhibitors (ICI) was assessed by IFNγ gene induction. Interestingly, IFNγ EVOC induction was numerically higher when anti-CTLA4 was added to anti-PD-L1 treatment, supporting the notion that anti-CTLA4 impacts cancer partly through tumor-resident immune cells. In parallel, immunohistochemistry (IHC) for key immune-related proteins was performed on the formalin-fixed paraffin embedded (FFPE) corresponding tumors. EVOC IFNγ induction by ICI correlated with basal non-induced IFNγ, CD8, CD4 and FOXP3 mRNA levels within EVOCs and with tumor-FFPE-IHC for CD8 and granzyme B. A weaker correlation was seen with tumor-FFPE-IHC for CD3, CD4, CD68, FOXP3 and tumor-PD-L1. Tertiary lymphoid structure density was also correlated with the ICI response. Our study provides novel data about biomarkers that correlate with ICI-induced response of early stage NSCLC. Retention of the microenvironment and minimal addition of exogenous factors suggest this model to reliably represent the original tumor. The cluster-based EVOC model we describe can provide a valuable, yet simple and widely applicable tool for the study of immunotherapy in NSCLC.

MiR-21, EGFR and PTEN in non-small cell lung cancer: an in situ hybridisation and immunohistochemistry study

AIMS

To analyse microRNA (miR)-21 distribution and expression at the cellular level in non-small cell lung cancer (NSCLC). MiR-21 is an oncogenic microRNA overexpressed in NSCLC. In previous studies, overexpression of miR-21 was evaluated from the tumour bulk by quantitative reverse transcription PCR with results expressed on average across the entire cell population.

METHODS

We used in situ hybridisation and immunohistochemistry to assess the correlation between miR-21 levels and the expression of markers that may be possible targets (epidermal growth factor reaction) or may be involved in its upregulation (phosphatase and tensin homolog (PTEN), p53). The Pearson's χ² tests was used to assess correlation with clinicopathological data and with miR-21 expression both in tumour and tumour stroma.

RESULTS

Cytoplasmic staining and expression of Mir-21 were detected in the tumours and in associated stromal cells. Expression was highest in the stroma immediately surrounding the tumour cells and decreased as the distance from the tumour increased. No expression of miR-21 was found in normal lung parenchyma and a significant association was found between tumour localised miR-21 and PTEN.

CONCLUSIONS

Presence of miR-21 in both cell tumour and stromal compartments of NSCLC and the relationship with PTEN confirms miR-21 as a microenvironment signalling molecule, possibly inducing epithelial mesenchymal transition and invasion by targeting PTEN in the stromal compartment possibly through exosomal transport. In situ immunohistochemical studies such as ours may help shed light on the complex interactions between miRNAs and its role in NSCLC biology.

Transformation to small cell lung cancer as a mechanism of resistance to immunotherapy in non-small cell lung cancer

OBJECTIVES

Non-small cell lung cancer (NSCLC) is the leading cause of cancer-related death world-wide. Immune checkpoint inhibitors (ICI) have become the most promising type of treatment in oncology in general, and significantly so in NSCLC. Limited data is available about mechanisms of primary resistance. Data is lacking about mechanisms involved in acquired resistance or mixed responses in NSCLC. We aimed to identify mechanisms of resistance by studying biopsies taken from sites of secondary progression.

MATERIALS AND METHODS

We identified all cases of NSCLC that have received ICI for advanced disease in our institute. Of these cases, those that have demonstrated acquired resistance or mixed responses, and have underwent a biopsy from a progressive lesion were analyzed. Selected specimens were subjected to next-generation sequencing (NGS; Oncomine™ Solid Tumour Fusion Transcript Kit).

RESULTS

Out of 664 lung cancer cases, 249 were NSCLC that have received ICI. Of these, eight cases matched our search criteria. Two of them demonstrated transformation to small cell lung cancer (SCLC; 2/8, 25%). NGS verified a common origin to a matched pre-treatment NSCLC specimen and an on-treatment progressive SCLC specimen. In two cases no tumor cells were found and in the remaining four the pathology was similar to the initial biopsy. In one of the cases of SCLC transformation platinum-etoposide chemotherapy was administered, with short-term benefit only and further disease progression.

CONCLUSION

Mechanisms of acquired resistance to ICI include SCLC transformation. Repeat biopsies of progressing lesions after initial response or in cases of mixed response can shed light on mechanisms of resistance.

Neoadjuvant pembrolizumab (Pembro) for early stage non-small cell lung cancer (NSCLC): Updated report of a phase I study, MK3475-223

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Background: Resected NSCLC clinical stage I or II harbor a 5 year survival of only 30-50%. Immunotherapy might be more effective in low-burden disease. We hypothesized that neo-adjuvant immunotherapy is a feasible, safe and effective treatment (Tx) for early stage NSCLC. Methods: MK3475-223 is an ongoing phase I study of neoadjuvant pembrolizumab in stage I-II NSCLC. All Pembro Txs are 200mg q 3 weeks (wks). Objectives: determine safety; recommended phase 2 dose/schedule; pathological & radiological response. Doses-schedule limiting toxicities (DLT) were defined as significant surgical complications (bleeding, delayed wound healing, ARDS, prolonged air-leak) or a significant delay of surgery. The doses-schedule escalation cohorts were (i) single pembro dose 3 wk prior to surgery; (ii) 2 pembro doses, 2 wks later surgery; (iii) 2 pembro doses, 1 wk later surgery. Expansion cohort received the doses-schedule of cohort (iii). Percentages of remaining viable tumor in the post-Tx were assessed, 10% or less was considered amajor pathological response (MPR). IHC for pre-Tx PDL1 was done. Efficacy was evaluated for the patients who had received 2 doses of pembrolizumab. Results: No DLT occurred in the dose-schedule escalation cohorts. 10 patients received 2 cycles of neo-adjuvant pembrolizumab. 4 patients achieved a MPR (4/10 who received 2 cycles of pembro; 40%; 95% C.I. 16.7-68.8%). No correlation is seen between the levels of PDL1 pre-Tx and the pathologic response. Size of the tumor and N status was also not in any apparent correlation with MPR (data not shown). Interestingly, all of the MPR cases had a relatively long interval from 1st Tx till surgery. Clinical trial information: NCT02938624. Conclusions: Neo-adjuvant pembro is safe and feasible. A promising sign of efficacy is seen. Achieving MPR might require a longer 1st-Tx-surgery interval. Predictive biomarkers for response might be different from those in advanced disease. Recruitment and correlative studies are ongoing.[Table: see text]

Flexible bronchoscopy and cryoextraction for critical airway obstruction caused by an endobronchial angioleiomyoma

Angioleiomyomas are rare airway tumours with potential to cause central airway obstruction or haemoptysis. Methods described to manage them include surgical resection, or rigid bronchoscopy and thermal ablation techniques. We describe a case presenting with central airway obstruction, safely and effectively treated with cryoextraction of the tumour using flexible bronchoscopy.

Comparative effectiveness of intensity modulated radiation therapy to 3-dimensional conformal radiation in locally advanced lung cancer: pathological and clinical outcomes

OBJECTIVE

Intensity-modulated radiotherapy (IMRT) has better normal-tissue sparing compared with 3-dimensional conformal radiation (3DCRT). We sought to assess the impact of radiation technique on pathological and clinical outcomes in locally advanced non-small cell lung cancer (LANSCLC) treated with a trimodality strategy.

METHODS

Retrospective review of LANSCLC patients treated from August 2012 to August 2018 at Sheba Medical Center, Israel. The trimodality strategy consisted of concomitant chemoradiation to 60 Gray (Gy) followed by completion surgery. The planning target volume (PTV) was defined by co-registered PET/CT. Here we compare the pathological regression, surgical margin status, local control rates (LC), disease free (DFS) and overall survival (OS) between 3DCRT and IMRT.

RESULTS

Our cohort consisted of 74 patients with mean age 62.9 years, male in 51/74 (69%), adenocarcinoma in 46/74 (62.1%), stage 3 in 59/74 (79.7%) and chemotherapy in 72/74 (97.3%). Radiation mean dose: 59.2 Gy (SD ± 3.8). Radiation technique : 3DCRT in 51/74 (68.9%), IMRT in 23/74 (31%). Other variables were similar between groups.Major pathological response (including pathological complete response or less than 10% residual tumor cells) was similar: 32/51 (62.7%) in 3DCRT and 15/23 (65.2%) in IMRT, p=0.83. Pathological complete response (pCR) rates were similar: 17/51 (33.3%) in 3DCRT and 8/23 (34.8%) in IMRT, p=0.9. Surgical margins were negative in 46/51 (90.1%) in 3DCRT vs. 17/19 (89.4%) in IMRT (p=1.0).The 2-year LC rates were 81.6% (95% CI 69-89.4%); DFS 58.3% (95% CI 45.5-69%) and 3-year OS 70% (95% CI57-80%). Comparing radiation techniques, there were no significant differences in LC (p=0.94), DFS (p=0.33) and OS (p=0.72).

CONCLUSION

When used to treat LANSCLC in the neoadjuvant setting, both IMRT and 3DCRT produce comparable pathological and clinical outcomes.

ADVANCES IN KNOWLEDGE

This study validates the real-world effectiveness of IMRT compared to 3DCRT.

Recurrent acute cellular rejection graded ISHLT 1R early after heart transplantation negatively affects long-term outcomes: The prognostic significance of 1990 ISHLT grades 1B and 2

PURPOSE

We investigated the implications of early recurrent 1R rejections for long-term outcomes after heart transplantation (HT) and evaluated the prognostic significance of 1990 ISHLT grading 1B/2 versus 1A.

METHODS

Data on all patients who underwent HT between 1992 and 2017 were reviewed. Patients with ≥2 endomyocardial biopsies graded 1R in the first 3 months were classified as "recurrent 1R." Those patients were further categorized according to 1A vs. 1B/2. Outcomes (>3 months) were long-term rejections and the combined endpoint of cardiac allograft vasculopathy (CAV) and cardiovascular (CV) mortality.

RESULTS

Sixty-nine out of 228 patients were classified as recurrent grade 1R. In the recurrent 1R group, 2R rejection rate was significantly higher (2.6 ± 0.6 vs 1.2 ± 0.4, p = 0.03), while survival free of rejections was lower (5-year: 57.1% vs. 72.3%, p = 0.022). Multivariate analysis showed that early recurrent 1R rejection was associated with a 30% increased risk for subsequent major rejection. Among 28 patients classified as 1B/2 of the recurrent group, rejection scores were higher, while survival free of rejections was lower, compared to 37 patients of the recurrent group classified as 1A (5-year: 57.1% vs. 72.7%, p = 0.013). Kaplan-Meier analysis showed that CAV/CV mortality at 10 years of follow-up was significantly higher among the recurrent 1R group (38% vs. 18% p < 0.05). Multivariate analysis showed that early recurrent 1R rejections were associated with a 2.5-fold increased risk for CAV/CV mortality.

CONCLUSION

Early recurrent grade 1R rejections negatively affect long-term outcomes. The adverse outcomes are experienced mainly by 1R patients subcategorized as1B/2 and not 1A.

Risk of early, intermediate, and late rejection following heart transplantation: Trends over the past 25 years and relation to changes in medical management. Tertiary center experience: The Sheba Heart Transplantation Registry

AIM

To explore the trends in the risk for rejection following heart transplantation (HT) over the past 25 years, and their relation to changes in medical management.

METHODS

The study population comprised 216 HT patients. Rejection periods were defined as follows: 0-3 months (early), 3-12 months (intermediate), and 12+ months (late). HT era was dichotomized as follows: 1991-1999 (remote era) and 2000-2016 (recent era). Medication combination was categorized as newer (TAC, MMF, and everolimus) vs older therapies (AZA, CSA).

RESULTS

Multivariate analysis showed that patients who underwent HT during the recent era experienced a significant reduction in the risk for major rejection. These findings were consistent for early (OR = 0.44 [95% CI 0.22-0.88]), intermediate (OR = 0.02 [95% CI 0.003-0.11]), and late rejections (OR = 0.18 [95% CI 0.05-0.52]). Using the year of HT as a continuous measure showed that each 1-year increment was independently associated with a significant reduction in the risk for early, intermediate, and late rejections (5%, 21%, 18%, respectively). In contrast, the risk reduction associated with newer types of immunosuppressive therapies was not statistically significant after adjustment for the treatment period.

CONCLUSIONS

Major rejection rates following HT have significantly declined over the past 2 decades even after adjustment for changes in immunosuppressive therapies, suggesting that other factors may also play a role in the improved outcomes of HT recipients.

A novel immune resistance mechanism of melanoma cells controlled by the ADAR1 enzyme

The blossom of immunotherapy in melanoma highlights the need to delineate mechanisms of immune resistance. Recently, we have demonstrated that the RNA editing protein, adenosine deaminase acting on RNA-1 (ADAR1) is down-regulated during metastatic transition of melanoma, which enhances melanoma cell proliferation and tumorigenicity. Here we investigate the role of ADAR1 in melanoma immune resistance.Importantly, knockdown of ADAR1 in human melanoma cells induces resistance to tumor infiltrating lymphocytes in a cell contact-dependent mechanism. We show that ADAR1, in an editing-independent manner, regulates the biogenesis of miR-222 at the transcription level and thereby Intercellular Adhesion Molecule 1 (ICAM1) expression, which consequently affects melanoma immune resistance. ADAR1 thus has a novel, pivotal, role in cancer immune resistance. Corroborating with these results, the expression of miR-222 in melanoma tissue specimens was significantly higher in patients who had no clinical benefit from treatment with ipilimumab as compared to patients that responded clinically, suggesting that miR-222 could function as a biomarker for the prediction of response to ipilimumab.These results provide not only novel insights on melanoma immune resistance, but also pave the way to the development of innovative personalized tools to enable optimal drug selection and treatment.

Lack of Microsomal Prostaglandin E 2 Synthase-1 in Bone Marrow–Derived Myeloid Cells Impairs Left Ventricular Function and Increases Mortality After Acute Myocardial Infarction

Background—

Microsomal prostaglandin E 2 synthase-1 (mPGES-1), encoded by the Ptges gene, catalyzes prostaglandin E 2 biosynthesis and is expressed by leukocytes, cardiac myocytes, and cardiac fibroblasts. Ptges −/− mice develop more left ventricle (LV) dilation, worse LV contractile function, and higher LV end-diastolic pressure than Ptges +/+ mice after myocardial infarction. In this study, we define the role of mPGES-1 in bone marrow–derived leukocytes in the recovery of LV function after coronary ligation.

Methods and Results—

Cardiac structure and function in Ptges +/+ mice with Ptges +/+ bone marrow ( BM +/+ ) and Ptges +/+ mice with Ptges −/− BM ( BM −/− ) were assessed by morphometric analysis, echocardiography, and invasive hemodynamics before and 7 and 28 days after myocardial infarction. Prostaglandin levels and prostaglandin biosynthetic enzyme gene expression were measured by liquid chromatography–tandem mass spectrometry and real-time polymerase chain reaction, immunoblotting, immunohistochemistry, and immunofluorescence microscopy, respectively. After myocardial infarction, BM −/− mice had more LV dilation, worse LV systolic and diastolic function, higher LV end-diastolic pressure, more cardiomyocyte hypertrophy, and higher mortality but similar infarct size and pulmonary edema compared with BM +/+ mice. BM −/− mice also had higher levels of COX-1 protein and more leukocytes in the infarct, but not the viable LV, than BM +/+ mice. Levels of prostaglandin E 2 were higher in the infarct and viable myocardium of BM −/− mice than in BM +/+ mice.

Conclusions—

Lack of mPGES-1 in bone marrow–derived leukocytes negatively regulates COX-1 expression, prostaglandin E 2 biosynthesis, and inflammation in the infarct and leads to impaired LV function, adverse LV remodeling, and decreased survival after acute myocardial infarction.

The effects of subjectively significant stimuli on subsequent cognitive brain activity

OBJECTIVE

To study brain activity modulation by preceding subjectively significant stimuli. Brain activity related to emotional and cognitive processing has been typically traced with fMRI's temporal resolution of seconds. In this study, the time course of activation in the brain areas involved was traced with millisecond temporal resolution.

METHODS

Electrophysiological brain activity was recorded while 12 normal subjects performed an auditory cued attention task, with subjectively significant verbal distracters. Verbal distracters, administered at different times between the cue and the target in one third of the trials, were first names, whose subjective significance was individually assessed after the experiment using a validated questionnaire. Intracranial sources of scalp-recorded electrical activity were estimated and statistical comparisons were conducted to assess the effects and interactions of (1) cue validity; and (2) subjective significance of distracters, on brain activity evoked by the targets.

RESULTS

Significant cue validity effects were found. Language-related areas were most involved following neutral distracters. Emotion-related areas were most involved following subjectively significant distracters. Thus, cue validity and distracter effects seem to have distinct effects.

SIGNIFICANCE

The results indicate an effect of subjectively significant distracters on subsequent brain activity with an interaction between cognitive and emotional processes.

Wet SEM: A Novel Method for Rapid Diagnosis of Brain Tumors

The authors present the application of wet SEM for histopathological assessment, a technology for imaging fully hydrated samples at atmospheric pressure in a scanning electron microscope (SEM). Both transmission and scanning electron microscopy techniques usually require long and complex sample preparation of the tissues. In marked contrast, a rapid preparation of tissues is described for evaluation by SEM imaging. The wet SEM technology successfully demonstrated both histological and ultrastructural features of several CNS tumors: Rosette formation and intracytoplasmic lumens were observed in ependymoma; numerous fibrillary processes in fibrillary astrocytoma; and focal rosette formation with no intracytoplasmic lumens in medulloblastoma. Application of this method simultaneously with frozen section may improve rapid intraoperative diagnosis of these intracranial tumors.

The expression of three genes in primary non-small cell lung cancer is associated with metastatic spread to the brain

PURPOSE

Brain metastases affect 25% of patients with non-small cell lung cancer (NSCLC). We hypothesized that the expression of genes in primary NSCLC tumors could predict brain metastasis and be used for identification of high-risk patients, who may benefit from prophylactic therapy.

EXPERIMENTAL DESIGN

The expression of 12 genes was measured by real-time quantitative reverse transcriptase PCR in 142 frozen NSCLC tissue samples. Univariate and multivariate Cox regression analysis was used to analyze the correlation between gene expression and the occurrence of brain metastasis. Immunohistochemistry on independent samples was used to verify the findings.

RESULTS

A score based on the expression levels of three genes, CDH2 (N-cadherin), KIFC1, and FALZ, was highly predictive of brain metastasis in early and advanced lung cancer. The probability of remaining brain metastasis-free at 2 years after diagnosis was 90.0+/-9.5% for patients with stage I/stage II tumors and low score compared with 62.7+/-12% for patients with high score (P<0.01). In patients with more advanced lung cancer, the brain metastasis-free survival at 24 months was 89% for patients with low score compared with only 37% in patients with high score (P<0.02). These results were confirmed by immunohistochemical detection of N-cadherin in independent cohort of primary NSCLC.

CONCLUSIONS

The expression levels of three genes in primary NSCLC tumors may be used to identify patients at high risk for brain metastasis who may benefit from prophylactic therapy to the central nervous system.

PROGNOSTIC VALUE OF hMLH1 AND hMSH2 IMMUNOHISTOCHEMICAL EXPRESSION IN NON-SMALL CELL LUNG CANCER. A TISSUE MICROARRAY STUDY

BACKGROUND

hMLH1 and hMSH2 genes are both known to play a role in DNA mismatch repair. Nonetheless, the clinical significance of hMLH1 and hMSH2 protein expression in lung cancers remains unclear.

AIM

The aim of this study was to investigate the immunohistochemical expression of hMLH1 and hMSH2 proteins in tumor specimens from 179 non-small cell lung cancer (NSCLC) patients using a tissue microarray technique and to correlate these results with other clinicopathological variables, including the disease specific and overall survivals.

METHOD

hMLH1 and hMSH2 protein expression was evaluated by immunohistochemistry using monoclonal antibodies G168-728 for hMLH1 and FE11 for hMSH2 protein expression analysis. The Pearson chi2 test was used to compare the hMLH1 and hMSH2 alterations among the cases and between various clinical and laboratory variables. P < or = 0.05 was considered statistically significant.

RESULTS

Alteration of hMLH1 and hMSH2 protein expression was observed in 10 % of patients. No significant correlation was found between the protein expression and patient age, smoking status, tumor histology or disease stage and disease free and overall survival.

CONCLUSIONS

Alterations in the expression of hMLH1 and hMSH2 proteins did not have any prognostic value in stage III. NSCLC patients.

Relativistic ejecta from X-ray flash XRF 060218 and the rate of cosmic explosions

Over the past decade, long-duration gamma-ray bursts (GRBs)--including the subclass of X-ray flashes (XRFs)--have been revealed to be a rare variety of type Ibc supernova. Although all these events result from the death of massive stars, the electromagnetic luminosities of GRBs and XRFs exceed those of ordinary type Ibc supernovae by many orders of magnitude. The essential physical process that causes a dying star to produce a GRB or XRF, and not just a supernova, is still unknown. Here we report radio and X-ray observations of XRF 060218 (associated with supernova SN 2006aj), the second-nearest GRB identified until now. We show that this event is a hundred times less energetic but ten times more common than cosmological GRBs. Moreover, it is distinguished from ordinary type Ibc supernovae by the presence of 10(48) erg coupled to mildly relativistic ejecta, along with a central engine (an accretion-fed, rapidly rotating compact source) that produces X-rays for weeks after the explosion. This suggests that the production of relativistic ejecta is the key physical distinction between GRBs or XRFs and ordinary supernovae, while the nature of the central engine (black hole or magnetar) may distinguish typical bursts from low-luminosity, spherical events like XRF 060218.

From a radial operating theatre to a self-contained operating table

Equipment congestion and a disarray of wires, tubes and lines (the spaghetti syndrome) is a common scenario in operating theatres. The radial arrangement of input and output signals and their interconnecting lines has been identified as the main source of clutter and congestion in this environment. Our aim was to present a comprehensive design concept for reducing electrical and physical clutter in the operating theatre. Data were collected from different operating theatres, including identification and sorting of equipment, cables, tubes and lines according to the direction and the features of the transmitted information and materials. We suggest a concept of a self-contained, 'built-in' operating table as a design solution for avoiding the clutter and congestion caused by the radial configuration. The operating table will function as a central integrated unit for management of the entire process of patient flow and control of supply systems and environmental conditions.

Fulminant vasculitis: a rare fatal complication of lymphoma

Vasculitis is rarely associated with lymphoma; however, most cases associated with lymphoma are cutaneous. Systemic vasculitis in association with lymphoma is usually an indolent and non-fatal complication. Two patients presented to our department with fulminant vasculitis with a fatal course and were later diagnosed with lymphoma. A search of the literature for systemic fulminant vasculitis in association with lymphoma disclosed eight case reports. We suggest that lymphoma should be considered as a possible etiology in patients with fulminant systemic vasculitis. The therapeutic implications of such an association are discussed.

Neurophysiological correlates of subjective significance

OBJECTIVE

The neural substrates of emotional response have traditionally been studied using universal sets of emotionally loaded stimuli, regardless of their subjective significance for the individual subject. Related brain activity has been typically traced with fMRI's temporal resolution of seconds. In this study, unique brain responses to subjectively significant stimuli were analyzed and traced with millisecond temporal resolution.

METHODS

Electrical brain activity (event related potentials) was recorded from 16 normal subjects, to subjectively significant auditory stimuli and its brain sources were imaged. Subjective significance of the stimuli was individually assessed for each subject.

RESULTS

Unique and significant brain activity to subjectively significant stimuli began as early as 200 ms after stimulus onset, with increased brain activity in the vicinity of several brain areas, including frontal gyri, Broca's area, Wernicke's area, insula, precuneus and cingulate gyri. The time course of activity in these areas was traced and found concurrent.

CONCLUSIONS

Although the subjectively significant stimuli of this study were not divided according to their positive or negative affective valence, they elicited a distinct brain response compared to neutral stimuli, with a uniform pattern across subjects.

SIGNIFICANCE

These results demonstrate that subjectively significant stimuli are associated with characteristic brain activity, that studying the neural substrate and time course of processing subjectively significant stimuli is feasible and that the neurophysiological manifestations of emotions are attainable.

Ear advantage and attention: an ERP study of auditory cued attention

The neurophysiological manifestations of left ear advantage to tonal stimuli and its interaction with attention have rarely been studied. Cued attention is a behavioral paradigm to assess the behavioral benefits and costs of allocating attention. In this task a cue predicts the location of a subsequent target to which the subject responds. In most cases the cue correctly predicts the target (valid cues) but at times it does not (invalid cues). Cued attention is a spatial paradigm with stimuli presented to either side. The objectives of this study were: (1) to find the neurophysiological correlates of the ear advantage phenomenon and (2) to assess the interaction of the stimulated side (right vs. left ear advantage) with attention, in a cued attention task. Significant effects on event-related potentials (ERPs) in the cued attention task indicated left ear and right hemisphere advantage. Effects were mostly confined to the right hemisphere. The results indicate interactions among left ear advantage, attention and dominant hand utilization. Ear advantage and attention may involve the same neural mechanisms. In spite of the left ear advantage effect on ERP components, hand dominance determines the final behavioral results (reaction times).