Pulmonary loose tumor tissue fragments and spread through air spaces (STAS): Invasive pattern or artifact? A critical review

The concept of loose tumor tissue fragments as a pattern of invasion in lung carcinoma has recently been proposed and is included in the 2015 WHO fascicle on the classification of lung tumors, so-called "spread through airs paces" or STAS. This inclusion is controversial, as there are significant data to support that this histologic finding represents an artifact of tissue handling and processing rather than a pattern of invasion. These data are summarized in this review. These data are summarized in this review and support the conclusion that the inclusion of STAS in the WHO classification for lung cancer as a pattern of invasion was premature and erroneous. In our opinion, these tumor cell clusters or loose cells appear to be simply an artifact, although one which may or may not pinpoint to a high-grade tumor with discohesive cells and adverse prognosis.

Immunohistochemistry of Pulmonary Biomarkers: A Perspective From Members of the Pulmonary Pathology Society

The use of immunohistochemistry for the determination of pulmonary carcinoma biomarkers is a well-established and powerful technique. Immunohistochemisty is readily available in pathology laboratories, is relatively easy to perform and assess, can provide clinically meaningful results very quickly, and is relatively inexpensive. Pulmonary predictive biomarkers provide results essential for timely and accurate therapeutic decision making; for patients with metastatic non-small cell lung cancer, predictive immunohistochemistry includes ALK and programmed death ligand-1 (PD-L1) (ROS1, EGFR in Europe) testing. Handling along proper methodologic lines is needed to ensure patients receive the most accurate and representative test outcomes.

Beneficial Outcome of Losartan Therapy Depends on Type of FBN1 Mutation in Marfan Syndrome

BACKGROUND

It has been shown that losartan reduces aortic dilatation in patients with Marfan syndrome. However, treatment response is highly variable. This study investigates losartan effectiveness in genetically classified subgroups.

METHODS AND RESULTS

In this predefined substudy of COMPARE, Marfan patients were randomized to daily receive losartan 100 mg or no losartan. Aortic root dimensions were measured by MRI at baseline and after 3 years. FBN1 mutations were classified based on fibrillin-1 protein effect into (1) haploinsufficiency, decreased amount of normal fibrillin-1, or (2) dominant negative, normal fibrillin-1 abundance with mutant fibrillin-1 incorporated in the matrix. A pathogenic FBN1 mutation was found in 117 patients, of whom 79 patients were positive for a dominant negative mutation (67.5%) and 38 for a mutation causing haploinsufficiency (32.5%). Baseline characteristics between treatment groups were similar. Overall, losartan significantly reduced aortic root dilatation rate (no losartan, 1.3±1.5 mm/3 years, n=59 versus losartan, 0.8±1.4 mm/3 years, n=58; P=0.009). However, losartan reduced only aortic root dilatation rate in haploinsufficient patients (no losartan, 1.8±1.5 mm/3 years, n=21 versus losartan 0.5±0.8 mm/3 years, n=17; P=0.001) and not in dominant negative patients (no losartan, 1.2±1.7 mm/3 years, n=38 versus losartan 0.8±1.3 mm/3 years, n=41; P=0.197).

CONCLUSIONS

Marfan patients with haploinsufficient FBN1 mutations seem to be more responsive to losartan therapy for inhibition of aortic root dilatation rate compared with dominant negative patients. Additional treatment strategies are needed in Marfan patients with dominant negative FBN1 mutations.

CLINICAL TRIAL REGISTRATION

http://www.trialregister.nl/trialreg/index.asp; Unique Identifier: NTR1423.

No beneficial effect of general and specific anti-inflammatory therapies on aortic dilatation in Marfan mice

Aims

Patients with Marfan syndrome have an increased risk of life-threatening aortic complications, mostly preceded by aortic dilatation. In the FBN1^C1039G/+ Marfan mouse model, losartan decreases aortic root dilatation. We recently confirmed this beneficial effect of losartan in adult patients with Marfan syndrome. The straightforward translation of this mouse model to man is reassuring to test novel treatment strategies. A number of studies have shown signs of inflammation in aortic tissue of Marfan patients. This study examined the efficacy of anti-inflammatory therapies in attenuating aortic root dilation in Marfan syndrome and compared effects to the main preventative agent, losartan.

Methods and Results

To inhibit inflammation in FBN1^C1039G/+ Marfan mice, we treated the mice with losartan (angiotensin II receptor type 1 inhibitor), methylprednisolone (corticosteroid) or abatacept (T-cell-specific inhibitor). Treatment was initiated in adult Marfan mice with already existing aortic root dilatation, and applied for eight weeks. Methylprednisolone- or abatacept-treated mice did not reveal a reduction in aortic root dilatation. In this short time frame, losartan was the only treatment that significantly reduced aorta inflammation, transforming growth factor-beta (TGF-β) signaling and aortic root dilatation rate in these adult Marfan mice. Moreover, the methylprednisolone-treated mice had significantly more aortic alcian blue staining as a marker for aortic damage.

Conclusion

Anti-inflammatory agents do not reduce the aortic dilatation rate in Marfan mice, but possibly increase aortic damage. Currently, the most promising therapeutic drug in Marfan syndrome is losartan, by blocking the angiotensin II receptor type 1 and thereby inhibiting pSmad2 signaling.

Aortic disease in patients with Marfan syndrome: aortic volume assessment for surveillance

PURPOSE

To assess the reproducibility of aortic volume estimates and to serially test their use in patients with Marfan syndrome.

MATERIALS AND METHODS

The study was approved by the medical ethics committee and all subjects gave written informed consent. In 81 patients with Marfan syndrome and seven healthy control subjects, aortic volumes and diameters at baseline were estimated by means of contrast material-enhanced magnetic resonance (MR) imaging. At 3 years of follow-up, aortic expansion rate were calculated in a subgroup of 22 patients with Marfan syndrome. Total aortic volume was defined as volume measurement from the level of the aortic annulus to the aortic bifurcation. Intra- and interobserver agreement of aortic volume were calculated by using the intraclass correlation coefficient. Differences in variables were analyzed with the Student t test and logistic regression. Effect size was calculated.

RESULTS

Intra- and interobserver agreement of aortic volume calculation was 0.996 and 0.980, respectively. Mean aortic volume was significantly greater in patients with Marfan syndrome than in control subjects (104 mL/m(2); 95% confidence interval [CI]: 95, 114 mL/m(2) vs 74 mL/m(2); 95% CI: 62, 87 mL/m(2); P < .001). In 22 patients with Marfan syndrome, mean aortic volume was increased at 3 years of follow-up (17 mL; 95% CI: 8, 26 mL; P = .001; effect size, 0.29), while mean aortic diameter did not increase significantly (0.4 mm; 95% CI: 0.0, 0.9 mm; P = .171; effect size, 0.13).

CONCLUSION

Assessment of aortic volume is highly reproducible and may be suited for use in the detection of aortic expansion in patients with Marfan syndrome.

SUPPLEMENTAL MATERIAL

http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.13122310/-/DC1.

Circulating transforming growth factor-β as a prognostic biomarker in Marfan syndrome

BACKGROUND

Patients with Marfan syndrome (MFS) are at risk for cardiovascular disease. Marfan associated mutations in the FBN1 gene lead to increased transforming growth factor-β (TGF-β) activation. The aim of this study was to investigate the role of plasma TGF-β as a biomarker for progressive aortic root dilatation and dissection.

METHODS

Plasma TGF-β level and aortic root diameter by means of echocardiography were assessed in 99 MFS patients. After 38 months of follow-up measurement of the aortic root was repeated and individual aortic root growth curves were constructed. Clinical events were evaluated. The primary composite endpoint was defined as aortic dissection and prophylactic aortic root replacement.

RESULTS

TGF-β levels were higher in MFS patients as compared to healthy controls (109 pg/ml versus 54 pg/ml, p<0.001). Higher plasma TGF-β levels correlated with larger aortic root dimensions (r=0.26, p=0.027), previous aortic root surgery (161 pg/ml versus 88 pg/ml, p=0.007) and faster aortic root growth rate (r=0.42, p<0.001). During 38 months of follow-up, 17 events were observed (four type B dissections and 13 aortic root replacements). Patients with TGF-β levels above 140 pg/ml had a 6.5 times higher risk of experiencing the composite endpoint compared to patients with TGF-β levels below 140 pg/ml (95% CI: 2.1 to 20.1, p=0.001) with 65% sensitivity and 78% specificity.

CONCLUSION

Elevated TGF-β level in patients with Marfan syndrome is correlated with larger aortic root diameters and faster aortic root growth. Level of plasma TGF-β predicts cardiovascular events and might serve as a prognostic biomarker in MFS.

Mental quality of life is related to a cytokine genetic pathway

BACKGROUND

Quality of life (QoL) in patients with chronic disease is impaired and cannot be solely explained by disease severity. We explored whether genetic variability and activity contributes to QoL in patients with Marfan syndrome (MFS), a genetic connective tissue disorder.

METHODOLOGY/PRINCIPAL FINDINGS

In 121 MFS patients, patient characteristics (i.e. demographics and MFS-related symptoms) were assessed. Patients completed the SF-36 to measure QoL. In addition, transcriptome wide gene expression and 484 Single Nucleotide Polymorphysms (SNPs) in cytokine genes were available. QoL was first analyzed and associated with patient characteristics. Patients' physical QoL was impaired and weakly related with age and scoliosis, whereas mental quality of life (MCS) was normal. To explain a largely lacking correlation between disease severity and QoL, we related genome wide gene expression to QoL. Patients with lower MCS scores had high expression levels of CXCL9 and CXCL11 cytokine-related genes (p=0.001; p=0.002); similarly, patients with low vitality scores had high expression levels of CXCL9, CXCL11 and IFNA6 cytokine-related genes (p=0.02; p=0.02; p=0.04), independent of patient characteristics. Subsequently, we associated cytokine related SNPs to mental QoL (MCS and vitality). SNP-cluster in the IL4R gene showed a weak association with MCS and vitality (strongest association p=0.0017). Although overall mental QoL was normal, >10% of patients had low scores for MCS and vitality. Post-hoc analysis of systemic inflammatory mediators showed that patients with lowest MCS and vitality scores had high levels of CCL11 cytokine (p=0.03; p=0.04).

CONCLUSIONS/SIGNIFICANCE

Variation in the cytokine genetic pathway and its activation is related to mental QoL. These findings might allow us to identify and, ultimately, treat patients susceptible to poor QoL.

MRI-assessed regional pulse wave velocity for predicting absence of regional aorta luminal growth in marfan syndrome

BACKGROUND

In patients with Marfan syndrome (MFS), increased aortic wall stiffening may lead to progressive aortic dilatation. Aortic Pulse Wave Velocity (PWV), a marker of wall stiffness can be assessed regionally, using in-plane multi-directional velocity-encoded MRI. This study examined the diagnostic accuracy of regional PWV for prediction of regional aortic luminal growth during 2-year follow-up in MFS patients.

METHODS

In twenty-one MFS patients (mean age 36 ± 15 years, 11 male) regional PWV and aortic luminal areas were assessed by 1.5 T MRI. At 2-year follow-up, the incidence of luminal growth, defined as mean luminal diameter increase >2mm was determined for five aortic segments (S1, ascending aorta; S2, aortic arch; S3, thoracic descending aorta, S4, supra-renal and S5, infra-renal abdominal aorta). Regional PWV at baseline was considered increased when exceeding age-related normal PWV (healthy volunteers (n=26; mean age 30 ± 10 years, 15 male)) by two standard-errors. Sensitivity and specificity of regional PWV-testing for prediction of regional luminal growth were determined.

RESULTS

Regional PWV at baseline was increased in 17 out of 102 segments (17%). Significant luminal growth at follow-up was reported in 14 segments (14%). The specificity of regional PWV-testing was ≥ 78% for all aortic segments, sensitivity was ≤ 33%.

CONCLUSIONS

Regional PWV was significantly increased in MFS patients as compared to healthy volunteers within similar age range, in all aortic segments except the ascending aorta. Furthermore, regional PWV-assessment has moderate to high specificity for predicting absence of regional aortic luminal growth for all aortic segments in MFS patients.

Evaluation of sampling density on the accuracy of aortic pulse wave velocity from velocity-encoded MRI in patients with Marfan syndrome

PURPOSE

To evaluate the effect of spatial (ie, number of sampling locations along the aorta) and temporal sampling density on aortic pulse wave velocity (PWV) assessment from velocity-encoded MRI in patients with Marfan syndrome (MFS).

MATERIALS AND METHODS

Twenty-three MFS patients (12 men, mean age 36 ± 14 years) were included. Three PWV-methods were evaluated: 1) reference PWV(i.p.) from in-plane velocity-encoded MRI with dense temporal and spatial sampling; 2) conventional PWV(t.p.) from through-plane velocity-encoded MRI with dense temporal but sparse spatial sampling at three aortic locations; 3) EPI-accelerated PWV(t.p.) with sparse temporal but improved spatial sampling at five aortic locations with acceleration by echo-planar imaging (EPI).

RESULTS

Despite inferior temporal resolution, EPI-accelerated PWV(t.p.) showed stronger correlation (r = 0.92 vs. r = 0.65, P = 0.03) with reference PWV(i.p.) in the total aorta, with less error (8% vs. 16%) and variation (11% vs. 27%) as compared to conventional PWV(t.p.) . In the aortic arch, correlation was comparable for both EPI-accelerated and conventional PWV(t.p.) with reference PWV(i.p.) (r = 0.66 vs. r = 0.67, P = 0.46), albeit 92% scan-time reduction by EPI-acceleration.

CONCLUSION

Improving spatial sampling density by adding two acquisition planes along the aorta results in more accurate PWV assessment, even when temporal resolution decreases. For regional PWV assessment in the aortic arch, EPI-accelerated and conventional PWV assessment are comparably accurate. Scan-time reduction makes EPI-accelerated PWV assessment the preferred method of choice.

Inflammation aggravates disease severity in Marfan syndrome patients

Background

Marfan syndrome (MFS) is a pleiotropic genetic disorder with major features in cardiovascular, ocular and skeletal systems, associated with large clinical variability. Numerous studies reveal an involvement of TGF-β signaling. However, the contribution of tissue inflammation is not addressed so far.

Methodology/Principal Findings

Here we showed that both TGF-β and inflammation are up-regulated in patients with MFS. We analyzed transcriptome-wide gene expression in 55 MFS patients using Affymetrix Human Exon 1.0 ST Array and levels of TGF-β and various cytokines in their plasma. Within our MFS population, increased plasma levels of TGF-β were found especially in MFS patients with aortic root dilatation (124 pg/ml), when compared to MFS patients with normal aorta (10 pg/ml; p = 8×10⁻⁶, 95% CI: 70–159 pg/ml). Interestingly, our microarray data show that increased expression of inflammatory genes was associated with major clinical features within the MFS patients group; namely severity of the aortic root dilatation (HLA-DRB1 and HLA-DRB5 genes; r = 0.56 for both; False Discovery Rate(FDR) = 0%), ocular lens dislocation (RAET1L, CCL19 and HLA-DQB2; Fold Change (FC) = 1.8; 1.4; 1.5, FDR = 0%) and specific skeletal features (HLA-DRB1, HLA-DRB5, GZMK; FC = 8.8, 7.1, 1.3; FDR = 0%). Patients with progressive aortic disease had higher levels of Macrophage Colony Stimulating Factor (M-CSF) in blood. When comparing MFS aortic root vessel wall with non-MFS aortic root, increased numbers of CD4+ T-cells were found in the media (p = 0.02) and increased number of CD8+ T-cells (p = 0.003) in the adventitia of the MFS patients.

Conclusion/Significance

In conclusion, our results imply a modifying role of inflammation in MFS. Inflammation might be a novel therapeutic target in these patients.

RNA isolation for transcriptomics of human and mouse small skin biopsies

Background

Isolation of RNA from skin biopsies presents a challenge, due to the tough nature of skin tissue and a high presence of RNases. As we lacked the dedicated equipment, i.e. homogenizer or bead-beater, needed for the available RNA from skin isolation methods, we adapted and tested our zebrafish single-embryo RNA-isolation protocol for RNA isolation from skin punch biopsies.

Findings

We tested our new RNA-isolation protocol in two experiments: a large-scale study with 97 human skin samples, and a small study with 16 mouse skin samples. Human skin was sampled with 4.0 mm biopsy punches and for the mouse skin different punch diameter sizes were tested; 1.0, 1.5, 2.0, and 2.5 mm. The average RNA yield in human samples was 1.5 μg with an average RNA quality RIN value of 8.1. For the mouse biopsies, the average RNA yield was 2.4 μg with an average RIN value of 7.5. For 96% of the human biopsies and 100% of the mouse biopsies we obtained enough high-quality RNA. The RNA samples were successfully tested in a transcriptomics analysis using the Affymetrix and Roche NimbleGen platforms.

Conclusions

Using our new RNA-isolation protocol, we were able to consistently isolate high-quality RNA, which is apt for further transcriptomics analysis. Furthermore, this method is already useable on biopsy material obtained with a punch diameter as small as 1.5 mm.

Critical appraisal of the revised Ghent criteria for diagnosis of Marfan syndrome

Marfan syndrome (MFS) is a connective tissue disorder with major features in cardiovascular, ocular and skeletal systems. Recently, diagnostic criteria were revised where more weight was given to the aortic root dilatation. We applied the revised Marfan nosology in an established adult Marfan population to define practical repercussions of novel criteria for clinical practice and individual patients. Out of 180 MFS patients, in 91% (n = 164) the diagnosis of MFS remained. Out of 16 patients with rejected diagnosis, four patients were diagnosed as MASS (myopia, mitral valve prolapse, borderline non-progressive aortic root dilatation, skeletal findings and striae) phenotype, three as ectopia lentis syndrome and in nine patients no alternative diagnosis was established. In 13 patients, the diagnosis was rejected because the Z-score of the aortic root was <2, although the aortic diameter was larger than 40 mm in six of them. In three other patients, the diagnosis of MFS was rejected because dural ectasia was given less weight in the revised nosology. Following the revised Marfan nosology, the diagnosis of MFS was rejected in 9% of patients, mostly because of the absence of aortic root dilatation defined as Z-score ≥2. Currently used Z-scores seem to underestimate aortic root dilatation, especially in patients with large body surface area (BSA). We recommend re-evaluation of criteria for aortic root involvement in adult patients with a suspected diagnosis of MFS.

Losartan therapy in adults with Marfan syndrome: study protocol of the multi-center randomized controlled COMPARE trial

BACKGROUND

Marfan syndrome (MFS) is one of the most common systemic disorders of connective tissue with the incidence of approximately 2-3 per 10 000 individuals. Aortic disease, leading to progressive aneurysmal dilatation and dissection is the main cause of morbidity and mortality of Marfan patients. Current treatment (e.g. beta blockers and elective surgery) does postpone but cannot prevent aortic complications in these patients. Recent studies have found transforming growth factor beta (TGF beta) to be involved in the aortic aneurysm formation. Losartan, an angiotensin II type 1 receptor blocker inhibits TGFbeta in a mouse model of Marfan syndrome leading to inhibition of aortic growth. The main objective of this trial is to assess whether losartan treatment leads to a clinically relevant decrease of aortic dilatation in adult patients with Marfan syndrome.

METHODS/DESIGN

COMPARE study (COzaar in Marfan Patients Reduces aortic Enlargement) is an open-label, randomized, controlled trial with blinded end-points. Treatment with losartan will be compared with no additional treatment after 3 years of follow-up. We will enroll 330 patients with MFS who will be randomly assigned to receive losartan or not. Patients taking beta-blockers will continue taking their standard treatment. The primary end-point is the largest change in aortic diameter at any aortic level measured by means of MRI. Secondary end-points are change in mortality, incidence of dissection, elective aortic surgery, aortic volume, aortic stiffness and ventricular function. We will also investigate gene and protein expression change in the skin under losartan therapy and create prediction models for losartan-treatment response and aortic dilatation.

DISCUSSION

The COMPARE study will provide important evidence of effects of losartan treatment in adult Marfan patient population. We expect losartan to significantly reduce the occurrence and progression of aortic dilatation. This trial investigates a wide spectrum of clinical, genetic and biochemical effects of losartan aiming to provide further insight in the pathogenesis and treatment of Marfan syndrome.

TRIAL REGISTRATION

Netherlands Trial Register NTR1423.