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Mesothelioma is a poor prognosis cancer of the mesothelial lining that develops in response to exposure to various agents including asbestos. Actin-Like Protein 6A (ACTL6A, BAF53a) is a SWI/SNF regulatory complex protein that is elevated in cancer cells and has been implicated as a driver of cancer cell survival and tumor formation. In the present study, we show that ACTL6A drives mesothelioma cancer cell proliferation, spheroid formation, invasion, and migration, and that these activities are markedly attenuated by ACTL6A knockdown. ACTL6A expression reduces the levels of the p21Cip1 cyclin-dependent kinase inhibitor and tumor suppressor protein. DNA binding studies show that ACTL6A interacts with Sp1 and p53 binding DNA response elements in the p21Cip1 gene promoter and that this is associated with reduced p21Cip1 promoter activity and p21Cip1 mRNA and protein levels. Moreover, ACTL6A suppression of p21Cip1 expression is required for maintenance of the aggressive mesothelioma cancer cell phenotype suggesting that p21Cip1 is a mediator of ACTL6A action. p53, a known inducer of p21Cip1 expression, is involved ACTL6A in regulation of p21Cip1 in some but not all mesothelioma cells. In addition, ACTL6A knockout markedly reduces tumor formation and this is associated with elevated tumor levels of p21Cip1. These findings suggest that ACTL6A suppresses p21Cip1 promoter activity to reduce p21Cip1 protein as a mechanism to maintain the aggressive mesothelioma cell phenotype.

Glutamine addiction is an important phenotype displayed in some types of cancer. In these cells, glutamine depletion results in a marked reduction in the aggressive cancer phenotype. Mesothelioma is an extremely aggressive disease that lacks effective therapy. In the present study we show that mesothelioma tumors are glutamine addicted suggesting that glutamine depletion may be a potential therapeutic strategy. We show that glutamine restriction, by removing glutamine from the medium or treatment with inhibitors that attenuate glutamine uptake (V-9302) or conversion to glutamate (CB-839), markedly reduces mesothelioma cell proliferation, spheroid formation, invasion and migration. Inhibition of the SLC1A5 glutamine importer, by knockout or treatment with V-9302, an SLC1A5 inhibitor, also markedly reduces mesothelioma cell tumor growth. A relationship between glutamine utilization and YAP1/TEAD signaling has been demonstrated in other tumor types, and the YAP1/TEAD signaling cascade is active in mesothelioma cells and drives cell survival and proliferation. We therefore assessed the impact of glutamine depletion on YAP1/TEAD signaling. We show that glutamine restriction, SLC1A5 knockdown/knockout, or treatment with V-9302 or CB-839, reduces YAP1 level, YAP1/TEAD-dependent transcription, and YAP1/TEAD target protein (e.g., CTGF, cyclin D1, COL1A2, COL3A1, etc.) levels. These changes are observed in both cells and tumors. These findings indicate that mesothelioma is a glutamine addicted cancer, show that glutamine depletion attenuates YAP1/TEAD signaling and tumor growth, and suggests that glutamine restriction may be useful as a mesothelioma treatment strategy.

Dosimetry for photodynamic therapy is dependent on multiple parameters. Critically, in vivo tissue optical properties and hemodynamics must be determined carefully to calculate the total delivered light dose.Spectroscopic analysis of diffuse reflectance measurements of tissues taken during a clinical trial of 2-(1-hexyloxyethyl)-2-devinyl pyropheophorbide-a-mediated photodynamic therapy for pleural malignancies.Diffuse reflectance measurements were taken immediately before and after photodynamic therapy. Measurements were analyzed with a nonlinearly constrained multiwavelength, multi-distance algorithm to extract tissue optical properties, tissue oxygen saturation, StO2, and total hemoglobin concentration (THC).A total of 25 patients were measured, 23 of which produced reliable fits for optical property extraction. For all tissue types, StO2 ranged through [24, 100]% and [22, 97]% for pre-photodynamic therapy (PDT) and post-PDT conditions, respectively. Mean THC ranged through [ 69,152 ] μM and [ 48,111 ] μM, for pre-PDT and post-PDT, respectively. Absorption coefficients, μa, ranged through [ 0.024 , 3.5 ] cm - 1 and [ 0.039 , 3 ] cm - 1 for pre-PDT and post-PDT conditions, respectively. Reduced scattering coefficients, μs', ranged through [ 1.4 , 73.4 ] cm - 1 and [ 1.2 , 64 ] cm - 1 for pre-PDT and post-PDT conditions, respectively.There were similar pre- and post-PDT tissue optical properties and hemodynamics. The high variability in each parameter for all tissue types emphasizes the importance of these measurements for accurate PDT dosimetry.

Mesothelioma is a highly aggressive cancer of the mesothelial lining that is caused by exposure to asbestos. Surgical resection followed by chemotherapy is the current treatment strategy, but this is marginally successful and leads to drug-resistant disease. We are interested in factors that maintain the aggressive mesothelioma cancer phenotype as therapy targets. Protein arginine methyltransferase 5 (PRMT5) functions in concert with the methylosome protein 50 (MEP50) cofactor to catalyze symmetric dimethylation of key arginine resides in histones 3 and 4 which modifies the chromatin environment to alter tumor suppressor and oncogene expression and enhance cancer cell survival. Our studies show that PRMT5 or MEP50 loss reduces H4R3me2s formation and that this is associated with reduced cancer cell spheroid formation, invasion, and migration. Treatment with sulforaphane (SFN), a diet-derived anticancer agent, reduces PRMT5/MEP50 level and H4R3me2s formation and suppresses the cancer phenotype. We further show that SFN treatment reduces PRMT5 and MEP50 levels and that this reduction is required for SFN suppression of the cancer phenotype. SFN treatment also reduces tumor formation which is associated with reduced PRMT5/MEP50 expression and activity. These findings suggest that SFN may be a useful mesothelioma treatment agent that operates, at least in part, via suppression of PRMT5/MEP50 function.

Objectives Soluble mesothelin-related protein (SMRP) and fibulin-3 serum levels may serve as diagnostic and prognostic biomarkers of malignant pleural mesothelioma (MPM). Here, we evaluate these markers for correlation to tumor volume, prognosis and response assessment in a clinical trial of immunogene therapy in combination with chemotherapy. Materials and methods Serial serum levels of SMRP and fibulin-3 were measured in adult patients with biopsy-proven MPM enrolled in two prospective clinical trials. Pre-therapy computed tomography (CT) measurements of tumor burden were calculated and correlated with pre-therapy serum SMRP and fibulin-3 levels in these two trials. Serological data were also correlated with radiological assessment of response using Modified RECIST criteria over the first 6 months of intrapleural delivery of adenovirus-IFN alpha (Ad.IFN-α) combined with chemotherapy. Results A cohort of 58 patients who enrolled in either a photodynamic therapy trial or immunotherapy clinical trial had available imaging and SMRP serological data for analysis of whom 45 patients had serological fibulin-3 data. The cohort mean total tumor volume was 387 cm3 (STD 561 cm3). Serum SMRP was detectable in 57 of 58 patients (mean 3.8 nM, STD 6.0). Serum fibulin-3 was detected in 44 of 45 patients (mean 23 ng/mL, STD 14). At pre-therapy baseline in these two trials, there was a strong correlation between tumor volume and serum SMRP levels (r = 0.61, p Conclusions Although our data show correlations of SMRP and fibulin-3 with initial tumor volumes as measured by CT scanning, the use of SMRP and fibulin-3 as serological biomarkers in the immunotherapy trial were not useful in following tumor response longitudinally.

Lymph node (LN) involvement is a poor prognostic factor for malignant pleural mesothelioma (MPM). However, to our knowledge, postresection outcomes of node-negative (cN0/pN0), occult pathologic nodal disease (cN0/pN+), and clinical node-positive disease (cN+) have not been compared to date.The National Cancer Data Base was queried for newly diagnosed, resected MPM with known clinical/pathologic LN information. Three cohorts were compared: cN0/pN0, cN+, and cN0/pN+. Multivariable logistic regression examined predictors of pathologic nodal upstaging. Kaplan-Meier analysis with propensity matching assessed overall survival (OS); multivariate Cox proportional hazards modeling examined predictors thereof.Of 1369 patients, 687 (50%) had cN0/pN0, 457 (33%) cN+, and 225 (16%) cN0/pN+ disease. Median follow-up was 29 months. In patients with cN0 disease, factors associated with pathologic nodal upstaging were younger age, greater number of examined LNs, and nonsarcomatoid histology (P .05 for all). Relative to pN0 cases, occult LN involvement (65% being pN2) was associated with 51% higher hazard of mortality on multivariate analysis (P = .005). Following propensity matching, the OS of cN0/pN+ was similar to cN+ cases (P = .281). On multivariate analysis, the number of involved LNs (continuous variable, P = .013), but not nodal tumor, node, metastasis (TNM) classification or LN ratio (P.05 for both), was associated with OS.Detecting occult nodal disease during resection for cN0 MPM is associated with poorer prognosis, with similar survival as cN+ cases, underscoring the importance of routine preoperative pathologic nodal assessment for potentially resectable MPM. The number of involved LNs (rather than current location-based classification) may provide more robust prognostic stratification for future TNM staging.

The distributions of light and tissue oxygenation (St O2 ) within the chest cavity were determined for 15 subjects undergoing macroscopic complete resection followed by intraoperative photodynamic therapy (PDT) as part of a clinical trial for the treatment of malignant pleural mesothelioma (MPM). Over the course of light delivery, detectors at each of eight different sites recorded exposure to variable fluence rate. Nevertheless, the treatment-averaged fluence rate was similar among sites, ranging from a median of 40-61 mW cm-2 during periods of light exposure to a detector. St O2 at each tissue site varied by subject, but posterior mediastinum and posterior sulcus were the most consistently well oxygenated (median St O2 >90%; interquartile ranges ~85-95%). PDT effect on St O2 was characterized as the St O2 ratio (post-PDT St O2 /pre-PDT St O2 ). High St O2 pre-PDT was significantly associated with oxygen depletion (St O2 ratio < 1), although the extent of oxygen depletion was mild (median St O2 ratio of 0.8). Overall, PDT of the thoracic cavity resulted in moderate treatment-averaged fluence rate that was consistent among treated tissue sites, despite instantaneous exposure to high fluence rate. Mild oxygen depletion after PDT was experienced at tissue sites with high pre-PDT St O2 , which may suggest the presence of a treatment effect.

Uniform light fluence distribution for patients undergoing photodynamic therapy (PDT) is critical to ensure predictable PDT outcomes. However, current practice when delivering intrapleural PDT uses a point source to deliver light that is monitored by seven isotropic detectors placed within the pleural cavity to assess its uniformity. We have developed a real-time infrared (IR) tracking camera to follow the movement of the light point source and the surface contour of the treatment area. The calculated light fluence rates were matched with isotropic detectors using a two-correction factor method and an empirical model that includes both direct and scattered light components. Our clinical trial demonstrated that we can successfully implement the IR navigation system in 75% (15/20) of the patients. Data were successfully analyzed in 80% (12/15) patients because detector locations were not available for three patients. We conclude that it is feasible to use an IR camera-based system to track the motion of the light source during PDT and demonstrate its use to quantify the uniformity of light distribution, which deviated by a standard deviation of 18% from the prescribed light dose. The navigation system will fail when insufficient percentage of light source positions is obtained (

Nodal involvement in malignant pleural mesothelioma (MPM) is a poor prognostic factor, and management remains highly debated. Because there are no prospective trials for this population, this investigation addressed a major knowledge gap by examining national practice patterns as well as survival outcomes. The National Cancer Database was queried for newly diagnosed cN1-3M0 MPM. Multivariable logistic regression ascertained factors associated with administering surgery. Kaplan-Meier analysis assessed overall survival (OS); multivariable Cox proportional hazards modeling examined factors associated with OS. No statistical intergroup comparisons were made herein. This was primarily owing to undeniable selection biases in these heterogeneous datasets; the presence of incomplete and inadequately granular clinical information (eg, intent and selection of treatment, preoperative assessment) cannot be accounted for by propensity matching or other such algorithms, thus potentially leading to misinterpretation. Of 2548 patients, 20%, 70%, and 9% had N1, N2, and N3 disease, respectively. Overall, 13% received surgery/chemotherapy, 47% underwent chemotherapy alone, 30% were observed, and 5% received resection without chemotherapy (5% had unknown treatment information). The median OS for all patients was 9.2 months. Relative to N1 cases, N2+ subjects were less likely to undergo resection, and they also experienced lower OS (P0.05 for both). The median OS in N1, N2, and N3 patients was 10.0, 9.1, and 8.5 months, respectively. In summary, nodal status is a prognostic factor in cN+ MPM. Expected outcomes for the overall population and by nodal classification are described, which should be considered when patients and multidisciplinary providers jointly weigh management options. Careful patient selection in this population is necessary, encompassing factors such as histology, age, performance status, and location(s) of nodal burden.

Transglutaminase 2 (TG2) is an important mesothelioma cancer cell survival protein. However, the mechanism whereby TG2 maintains mesothelioma cell survival is not well understood. We present studies showing that TG2 drives hepatocyte growth factor (HGF)-dependent MET receptor signaling to maintain the aggressive mesothelioma cancer phenotype. TG2 increases HGF and MET messenger RNA and protein levels to enhance MET signaling. TG2 inactivation reduces MET tyrosine kinase activity to reduce cancer cell spheroid formation, invasion and migration. We also confirm that HGF/MET signaling is a biologically important mediator of TG2 action. Reducing MET level using genetic methods or treatment with MET inhibitors reduces spheroid formation, invasion and migration and this is associated with reduced MEK1/2 and ERK1/2. In addition, MEK1/2 and ERK1/2 inhibitors suppress the cancer phenotype. Moreover, MET knockout mesothelioma cells form 10-fold smaller tumors compared to wild-type cells and these tumors display reduced MET, MEK1/2, and ERK1/2 activity. These findings suggest that TG2 maintains HGF and MET levels in cultured mesothelioma cells and tumors to drive HGF/MET, MEK1/2, and ERK1/2 signaling to maintain the aggressive mesothelioma cancer phenotype.

This article is a joint effort arising from a task force formed at a National Cancer Institute-International Association for the Study of Lung Cancer-Mesothelioma Applied Research Foundation Mesothelioma Clinical Trials Planning Meeting, held at the NIH in March 2017. Malignant pleural mesothelioma remains one of the most virulent and recalcitrant malignancies, still considered incurable, and in desperate need of clinical trials in order to make progress for our patients. Although not standard of care, there is compelling evidence that a select subgroup of mesothelioma patients benefit from a surgery-based multimodal approach. As it is not possible to achieve a microscopically complete resection with mesothelioma, there appears to be no role for surgery alone. Thus, it is anticipated that significant strides in the surgery-based treatment of this cancer will require trials that determine which complementary treatments best augment the cytoreductive efficacy of surgery. Although lung-sacrificing surgery for mesothelioma is fairly standardized, approaches to lung-sparing surgery are highly variable and lung sparing surgery is emerging internationally as the dominant extirpative procedure for this cancer. It is not currently possible to rigorously assess the contribution of the adjuvant treatments combined with surgery because of the variability in procedures used to debulk this cancer, the extreme variability of the cancer itself, the variability in patient selection, the variability in treatment of the inevitable recurrence, and even the variability in follow up schedules. This article is an effort to address these problems by suggesting a more uniform approach to the surgical procedure and also proposing a series of data collection forms that could be adopted immediately, with any eye toward collecting the information that will be necessary to facilitate patient selection and determine which aspects of mesothelioma surgery can and should be standardized - with the goal being extension of life while maintaining quality of life as an equal priority. Furthermore, a completely original contribution in this manuscript is the proposal of a grading system that takes the information from the surgical procedure data forms and generates a completeness of resection score. This is the initial effort to establish a common denominator for mesothelioma surgery that will allow for more accurate comparison between surgical series and better assessment of the impact of the treatments combined with surgery.

The median age at diagnosis for malignant pleural mesothelioma (MPM) is approximately 72 years. Elderly patients pose unique management challenges because of the increased risk of therapy-related toxicities and mortality. Because there are no high-volume retrospective studies, prospective trials, or dedicated treatment recommendations for this population, this investigation addresses a major knowledge gap by examining national practice patterns and postoperative/survival outcomes in elderly MPM patients. The National Cancer Database was queried for patients aged ≥ 80 years with newly diagnosed nonmetastatic MPM. Multivariable logistic regression ascertained factors associated with observation and surgery. Kaplan–Meier analysis assessed overall survival (OS), and multivariable Cox proportional hazards modeling examined factors associated with OS. Survival was also calculated following propensity matching. Additionally, postoperative outcomes were evaluated in surgical patients. Of 4526 patients, 2% received surgery and chemotherapy, 22% underwent chemotherapy alone, and 63% were observed. Respective median OS was 12.2, 9.5, and 4.1 months (p

Background Stereotactic body radiation therapy (SBRT) is standard for medically inoperable stage I non–small-cell lung cancer (NSCLC) and is emerging as a surgical alternative in operable patients. However, limited long-term outcomes data exist, particularly according to operability. We hypothesized long-term local control (LC) and cancer-specific survival (CSS) would not differ by fractionation schedule, tumor size or location, or operability status, but overall survival (OS) would be higher for operable patients. Patients and Methods All consecutive patients with stage I (cT1-2aN0M0) NSCLC treated with SBRT from June 2009 to July 2013 were assessed. Thoracic surgeon evaluation determined operability. Local failure was defined as growth following initial tumor shrinkage or progression on consecutive scans. LC, CSS, and OS were calculated using Cox proportional hazards regression. Results A total of 186 patients (204 lesions) were analyzed. Most patients were inoperable (82%) with Eastern Cooperative Oncology Group performance status of 1 (59%) or 2 (26%). All lesions received biological effective doses ≥ 100 Gy most commonly (94%) in 3 to 5 fractions. The median follow-up was 4.0 years. LC at 2 and 5 years were 95.6% (95% confidence interval, 92%-99%) and 93.7% (95% confidence interval, 90%-98%), respectively. Compared with operable patients, inoperable patients did not have significant differences in 5-year LC (93.1% vs. 96.7%; P = .49), nodal failure (31.4% vs. 11.0%; P = .12), distant failure (12.2% vs. 10.4%; P = .98), or CSS (80.6% vs. 91.0%; P = .45) but trended towards worse OS (34.2% vs. 45.3%; P = .068). Tumor size, location, and fractionation did not significantly influence outcomes. Conclusions SBRT has excellent, durable LC and CSS rates for early-stage NSCLC, although inoperable patients had somewhat lower OS than operable patients, likely owing to greater comorbidities.

Mesothelioma is a poor prognosis cancer of the mesothelial lining that develops in response to exposure to various agents including asbestos. Actin-Like Protein 6A (ACTL6A, BAF53a) is a SWI/SNF regulatory complex protein that is elevated in cancer cells and has been implicated as a driver of cancer cell survival and tumor formation. In the present study, we show that ACTL6A drives mesothelioma cancer cell proliferation, spheroid formation, invasion, and migration, and that these activities are markedly attenuated by ACTL6A knockdown. ACTL6A expression reduces the levels of the p21Cip1 cyclin-dependent kinase inhibitor and tumor suppressor protein. DNA binding studies show that ACTL6A interacts with Sp1 and p53 binding DNA response elements in the p21Cip1 gene promoter and that this is associated with reduced p21Cip1 promoter activity and p21Cip1 mRNA and protein levels. Moreover, ACTL6A suppression of p21Cip1 expression is required for maintenance of the aggressive mesothelioma cancer cell phenotype suggesting that p21Cip1 is a mediator of ACTL6A action. p53, a known inducer of p21Cip1 expression, is involved ACTL6A in regulation of p21Cip1 in some but not all mesothelioma cells. In addition, ACTL6A knockout markedly reduces tumor formation and this is associated with elevated tumor levels of p21Cip1. These findings suggest that ACTL6A suppresses p21Cip1 promoter activity to reduce p21Cip1 protein as a mechanism to maintain the aggressive mesothelioma cell phenotype.

Pleural effusions are common in patients with malignant pleural mesothelioma. They can cause dyspnea, decreased quality of life, and may even contribute to weight loss. Palliation, whether as a bridge to treatment or part of a definitive plan, should always be considered. Options for management reside in either pleurodesis or placement of a tunneled pleural catheter. Herein, we discuss the advantages and limitations of each along with current and evolving treatment paradigms to provide evidence to aid in the comprehensive decision management of these patients.

BACKGROUND: For malignant pleural mesothelioma (MPM), the benefit of resection, as well as the optimal surgical technique, remain controversial. In efforts to better refine patient selection, this retrospective observational cohort study queried the National Cancer Database in an effort to quantify and evaluate predictors of 30- and 90-day mortality between extrapleural pneumonectomy (EPP) and pleurectomy/decortication (P/D), as well as nonoperative management. METHODS: After applying selection criteria, cumulative incidences of mortality by treatment paradigm were graphed for the unadjusted and propensity-matched populations, as well as for six a priori age-based intervals (≤60, 61–65, 66–70, 71–75, 76–80, and ≥81 years). The interaction between age and hazard ratio (HR) for mortality between treatment paradigms was also graphed. Cox multivariable analysis ascertained factors independently associated with 30- and 90-day mortality. RESULTS: Of 10,723 patients, 2,125 (19.8%) received resection (n=438 EPP, n=1,687 P/D) and 8,598 (80.2%) underwent nonoperative management. The unadjusted 30/90-day mortality for EPP, P/D, and all operated cases was 3.0%/8.0%, 5.4%/14.1%, and 4.9%/12.8%, respectively. There were no short-term mortality differences between EPP and P/D following propensity-matching, within each age interval, or between age subgroups on interaction testing (P>0.05 for all). Nonoperative patients had a crude 30- and 90-day mortality of 9.9% and 24.6%, respectively. Several variables were identified as predictors of short-term mortality, notably patient age (HR 1.022, P

Background An electrical storm (ES) is a life-threatening condition that affects up to 20% of patients with implantable cardioverter defibrillators. In this small retrospective study, we report our results with left video-assisted thoracoscopic sympathectomy/ganglionectomy (VATSG) to treat refractory ES in low–ejection fraction patients who were not candidates for catheter ablation. Methods We identified 12 patients who presented with ES and underwent a total of 14 video-assisted thoracoscopic sympathectomy/ganglionectomy, including 3 patients on venoarterial extracorporeal membrane oxygenation. We reviewed demographic data, survival to discharge, number of cardioversions (before and after VATSG), need for readmissions, and need for right-sided procedures. Results In the 30 days before a left VATSG, mean number of shocks was 22.67 for all patients. For the patients who survived to discharge, the mean was 3.55 since surgery and the median was zero shocks after a median follow-up of 358 days. Six patients did not experience further cardioversions since the last VATSG and 5 were not readmitted for ventricular tachycardia. Two patients had staged bilateral procedures owing to recurrences; of those, 1 did not require further cardioversions. Conclusions Limited left VATSG is an appropriate and effective initial treatment for ES patients who are not candidates for catheter ablation, including those on venoarterial extracorporeal membrane oxygenation for hemodynamic support.

For the 3 histologic subtypes of malignant pleural mesothelioma (MPM)-epithelioid, sarcomatoid, and biphasic-the magnitude of benefit with surgical management remains underdefined.The National Cancer Data Base was queried for newly diagnosed nonmetastatic MPM with known histology. Patients in each histologic group were dichotomized into those receiving gross macroscopic resection versus lack thereof/no surgery. Kaplan-Meier analysis evaluated overall survival (OS) between cohorts; multivariable Cox proportional hazards modeling assessed factors associated with OS. After propensity matching, survival was evaluated for each histologic subtype with and without surgery.Overall, 4207 patients (68% epithelioid, 18% sarcomatoid, 13% biphasic) met the study criteria. Before propensity matching, patients with epithelioid disease experienced the highest median OS (14.4 months), followed by biphasic (9.5 months) and sarcomatoid (5.3 months) disease; this also persisted after propensity matching (P .001). After propensity matching, surgery was associated with significantly improved OS for epithelioid (20.9 vs. 14.7 months, P .001) and biphasic (14.5 vs. 8.8 months, P = .013) but not sarcomatoid (11.2 vs. 6.5 months, P = .140) disease. On multivariable analysis, factors predictive of poorer OS included advanced age, male gender, uninsured status, urban residence, treatment at community centers, and T4/N2 disease (all P .05). Chemotherapy and surgery were independently associated with improved OS, as was histology (all P .001).This large investigation evaluated surgical practice patterns and survival by histology for MPM and found that histology independently affects survival. Gross macroscopic resection is associated with significantly increased survival in epithelioid and biphasic, but not sarcomatoid, disease. However, the decision to perform surgery should continue to be individualized in light of available randomized data.

This study of a large, contemporary national database evaluated postoperative outcomes and overall survival (OS) for malignant pleural mesothelioma (MPM) by facility volume.The National Cancer Database was queried for newly-diagnosed non-metastatic MPM undergoing definitive surgery (extrapleural pneumonectomy (EPP) or pleurectomy/decortication (P/D)). Patients were dichotomized into those receiving therapy at a high-volume facility (HVF), defined a priori at the 90th percentile of case volume, with all others categorized as lower-volume facilities (LVFs). Statistics included multivariable logistic regression, Kaplan-Meier analysis, propensity-matching, and multivariable Cox proportional hazards modeling. Sensitivity analysis varied the dichotomized HVF-LVF cutoff and evaluated effects on postoperative outcomes and OS.Of 1307 patients, 621 (48%) were treated at LVFs and 686 (52%) at HVFs. HVFs were more often in the Middle/South Atlantic regions, and less likely in New England, South, and Midwest. Notably, 75% of procedures at HVFs were P/Ds, versus 84% at LVFs (p 0.001). Patients treated at HVFs experienced shorter length of postoperative hospitalization (p = 0.035), lower 30-day readmission rates (4.6% vs. 6.1%, p = 0.021), and lower 90-day mortality rates (10.0% vs. 14.6%, p = 0.029). Median OS for respective groups were 18 versus 15 months (p = 0.010), which were not significant following propensity-matching (p = 0.540). On multivariable analysis, facility volume did not independently predict for OS. Sensitivity analyses confirmed the postoperative outcomes and OS findings.This is the largest investigation to date assessing facility volume and outcomes following surgery for MPM. Although no independent effects on OS were observed, postoperative outcomes were more favorable at HVFs. These findings have implications for postoperative management, patient counseling, referring providers, and cost-effectiveness.

Purpose To determine, in a retrospective analysis of a large cohort of stage III non-small cell lung cancer patients treated with curative intent at our institution, whether having a pathologic complete response (pCR) influenced overall survival (OS) or freedom from recurrence (FFR) in patients who underwent definitive (≥60 Gy) neoadjuvant doses of chemoradiation (CRT). Methods and Materials At our institution, 355 patients with locally advanced non-small cell lung cancer were treated with curative intent with definitive CRT (January 2000-December 2013), of whom 111 underwent mediastinal reassessment for possible surgical resection. Ultimately 88 patients received trimodality therapy. Chi-squared analysis was used to compare categorical variables. The Kaplan-Meier analysis was performed to estimate OS and FFR, with Cox regression used to determine the absolute hazards. Results Using high-dose neoadjuvant CRT, we observed a mediastinal nodal clearance (MNC) rate of 74% (82 of 111 patients) and pCR rate of 48% (37 of 77 patients). With a median follow-up of 34.2 months (range, 3-177 months), MNC resulted in improved OS and FFR on both univariate (OS: hazard ratio [HR] 0.455, 95% confidence interval [CI] 0.272-0.763, P = .004; FFR: HR 0.426, 95% CI 0.250-0.726, P = .002) and multivariate analysis (OS: HR 0.460, 95% CI 0.239-0.699, P = .001; FFR: HR 0.455, 95% CI 0.266-0.778, P = .004). However, pCR did not independently impact OS (P = .918) or FFR (P = .474). Conclusions Mediastinal nodal clearance after CRT continues to be predictive of improved survival for patients undergoing trimodality therapy. However, a pCR at both the primary and mediastinum did not further improve survival outcomes. Future therapies should focus on improving MNC to encourage more frequent use of surgery and might justify use of preoperative CRT over chemotherapy alone.

Mesothelioma is an aggressive and fatal cancer of the mesothelial lining which is caused by asbestos exposure. The current treatment strategy is surgical resection followed by chemotherapy, but this is marginally successful and leads to drug resistant and recurrent disease. Mesothelioma cancer stem cells (MCS cells) comprise an important subpopulation of highly aggressive mesothelioma tumor cells that maintain tumor formation and mediate drug resistance. Our goal is to identify proteins that maintain the MCS cell and non-stem cancer cell survival as therapy targets. Protein arginine methyltransferase 5 (PRMT5) functions with the MEP50 cofactor to catalyze symmetric dimethylation of specific arginine resides in histones 3 and 4 to silence tumor suppressor gene expression and enhance cancer cell survival. Our studies show that loss of PRMT5 or MEP50 reduces H4R3me2s formation in MCS cells and that this is associated with a reduction in MCS cell spheroid formation, invasion and migration. Additionally, treatment with sulforaphane (SFN), a promising diet-derived cancer prevention and therapy agent, reduces PRMT5/MEP50 level and H4R3me2s formation, and suppresses the MCS cell phenotype. Moreover, forced expression of PRMT5/MEP50 antagonizes SFN suppression of the MCS cell phenotype, suggesting that loss of PRMT5/MEP50 is required for SFN action. SFN treatment also markedly reduces tumor formation and this is associated with reduced PRMT5/MEP50 expression and H4R3me2s formation. These findings suggest that SFN suppresses PRMT5/MEP50 function to attenuate the MCS cell phenotype and reduce tumor formation, and that SFN may be a useful mesothelioma prevention and therapy agent. Citation Format: Geraldine C. Ezeka, Gautam Adhikary, Sivaveera Kandasamy, Joseph Friedberg, Richard Eckert. Sulforaphane suppression of Prmt5 and Mep50 function suppresses the mesothelioma cancer stem cell phenotype [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB192.

Postsurgical empyema with bronchopleural fistula can be difficult to manage. We present a patient with postoperative empyema with bronchopleural fistula who was successfully treated nonoperatively by placing an intrabronchial valve to address the bronchopleural fistula, which allowed for safe administration of intrapleural fibrinolytics and antibiotics for definitive treatment of the empyema. Although the presence of a bronchopleural fistula is considered a contraindication to the administration of intrapleural tissue plasminogen activator and deoxyribonuclease, this case demonstrates a novel use of the intrabronchial valve that allowed these medications to be used.

Mesothelioma is an aggressive cancer that has a poor prognosis. Tumors develop in the mesothelial lining of the pleural and peritoneal cavities in response to asbestos exposure. Surgical debulking followed by chemotherapy is initially effective, but this treatment ultimately selects for resistant cells that form aggressive and therapy-resistant recurrent tumors. Mesothelioma cancer stem cells (MCS) are a highly aggressive subpopulation present in these tumors that are responsible for tumor maintenance and drug resistance. In this article, we examine the impact of targeting YAP1/TAZ/TEAD signaling in MCS cells. YAP1, TAZ, and TEADs are transcriptional mediators of the Hippo signaling cascade that activate gene expression to drive tumor formation. We show that two YAP1 signaling inhibitors, verteporfin and CA3, attenuate the MCS cell phenotype. Verteporfin or CA3 treatment reduces YAP1/TEAD level/activity to suppress MCS cell spheroid formation, Matrigel invasion, migration, and tumor formation. These agents also increase MCS cell apoptosis. Moreover, constitutively active YAP1 expression antagonizes inhibitor action, suggesting that loss of YAP1/TAZ/TEAD signaling is required for response to verteporfin and CA3. These agents are active against mesothelioma cells derived from peritoneal (epithelioid) and patient-derived pleural (sarcomatoid) mesothelioma, suggesting that targeting YAP1/TEAD signaling may be a useful treatment strategy. Implications: These studies suggest that inhibition of YAP1 signaling may be a viable approach to treating mesothelioma.

Posterior intercostal lymph nodes, previously undescribed for cancer staging, are part of the lymphatic drainage of the pleural space. This study assessed the impact of posterior intercostal lymph nodes on survival in patients undergoing extended pleurectomy/decortication for malignant pleural mesothelioma.As part of the thoracic lymphadenectomy, posterior intercostal lymph nodes were accessed by incising the endothoracic fascia at the level of the rib heads. These nodes were systematically harvested in 56 consecutive patients undergoing extended pleurectomy decortication in a clinical trial. The impact of these nodes on progression-free (PFS) and overall survival (OS) was analyzed by multiple statistical methods.Median PFS and OS were 11.6 and 25.5 months, respectively. In 6 of 56 patients (11%), posterior intercostal lymph nodes were the only positive nodes, and overall, 48.2% had posterior intercostal lymph node metastases. Patients with N2 disease had significantly poorer prognosis if the posterior intercostal lymph nodes were involved: PFS (7.3 vs 14.9 months, P = .002) and OS (14.4 vs 26.1 months, P = .028). In the multivariable models, after adjustment for nodal stage and other prognostic factors, intercostal nodes remained associated with a 2.5-fold elevated risk of progression (P.001) and a 2.3-fold elevated risk of death (P.001).Metastases to posterior intercostal lymph nodes independently more than doubled the risk of progression and death and were the only site of nodal metastases in 11% of patients. These nodes warrant further investigation, including nonoperative techniques to identify and factor them into treatment decision making.

Caring for patients undergoing lung-sparing surgery for malignant pleural mesothelioma is clinically challenging. It takes an experienced, highly skilled, and dedicated multidisciplinary team of thoracic surgery experts to care for these patients and their families. There are inherent challenges associated with the preoperative and postoperative care of patients undergoing lung-sparing surgery, beyond those commonly experienced in the general thoracic surgery patient population. Meticulous attention to every detail of their care and anticipating the common problems encountered postoperatively will support a patient’s successful recovery and ensure that they are safely discharged home from the hospital. This chapter will focus on the key elements the surgical team needs to focus on before, during, and after lung-sparing surgery for malignant pleural mesothelioma.

Purpose: “In situ vaccination” using immunogene therapy has the ability to induce polyclonal antitumor responses directed by the patient's immune system. Experimental Design: Patients with unresectable malignant pleural mesothelioma (MPM) received two intrapleural doses of a replication-defective adenoviral vector containing the human IFNα2b gene (Ad.IFN) concomitant with a 14-day course of celecoxib followed by chemotherapy. Primary outcomes were safety, toxicity, and objective response rate; secondary outcomes included progression-free and overall survival. Biocorrelates on blood and tumor were measured. Results: Forty subjects were treated: 18 received first-line pemetrexed-based chemotherapy, 22 received second-line chemotherapy with pemetrexed (n = 7) or gemcitabine (n = 15). Treatment was generally well tolerated. The overall response rate was 25%, and the disease control rate was 88%. Median overall survival (MOS) for all patients with epithelial histology was 21 months versus 7 months for patients with nonepithelial histology. MOS in the first-line cohort was 12.5 months, whereas MOS for the second-line cohort was 21.5 months, with 32% of patients alive at 2 years. No biologic parameters were found to correlate with response, including numbers of activated blood T cells or NK cells, regulatory T cells in blood, peak levels of IFNα in blood or pleural fluid, induction of antitumor antibodies, nor an immune-gene signature in pretreatment biopsies. Conclusions: The combination of intrapleural Ad.IFN, celecoxib, and chemotherapy proved safe in patients with MPM. OS rate was significantly higher than historical controls in the second-line group. Results of this study support proceeding with a multicenter randomized clinical trial of chemo-immunogene therapy versus standard chemotherapy alone. Clin Cancer Res; 22(15); 3791–800. ©2016 AACR.

DR. PASS: The topic for this roundtable discussions for Seminars in Thoracic and Cardiovascular Surgery is going to be surgery for mesothelioma. Our participants are Joe Friedberg, University of Maryland; Andrea Wolf, Icahn School of Medicine at Mount Sinai; David Rice, MD Anderson Cancer Center; and Wickii Vigneswaran, Loyola University Health System. All 4 of these surgeons were trained and are presently at high volume mesothelioma centers. Drs. Wolf and Friedberg were trained by Dr. Sugarbaker. Dr. Vigneswaran was trained at Mayo, and performed a large volume of surgical cases at the University of Chicago where he has a lot of cases that are both surgical as well as medical. Dr. Rice practices at MD Anderson and was one of the innovators of postoperative intensity-modulated radiotherapy (IMRT).

Introduction The lymphangitic carcinomatosis (LC) pattern of metastatic malignancy is associated with a poor prognosis but is currently not well defined in malignant pleural mesothelioma (MPM). Here, we report the incidence and prognostic significance of the radiographic development of LC in MPM following extended pleurectomy/decortication (EPD). Methods Consecutive patients with biopsy-proven MPM undergoing EPD with intraoperative photodynamic therapy (PDT) at our institution from 2008 to 2014 were included in this retrospective study. Patients without available post-surgical clinical or imaging data for direct review were excluded. CT images were reviewed by an experienced, board-certified thoracic radiologist and confirmed by consensus review. Overall survival (OS) and progression-free survival (PFS) were calculated by Kaplan Meier methodology. Hazard ratios were compared with a cox proportional hazard model. Results 44 patients underwent EPD with PDT during the study period and had available clinical and imaging data. During the follow-up period (median 34 months), 17 patients (39%) developed LC at a median of 10 months after surgery (IQR 5–21 months). 16 of the 17 patients who developed LC (94%) died during the follow-up period, compared to 17 of the 27 who did not develop LC (63%). OS for the LC versus non-LC group was 53% versus 93% at 1 year and 18% versus 67% at 3 years. LC was significantly associated with a lower OS (HR 4.07; 95% confidence interval 1.44–11.48; p = 0.008). PFS for the LC group versus non-LC group was 8 months (IQR 5–9 months) compared to 17 months (IQR 11–24 months) (p Conclusion LC is a common form of failure in MPM following EPD and is associated with a poor prognosis. Thus, further studies are warranted to determine if any evidence of preoperative LC should be an absolute contraindication to EPD and may warrant an EPP or no surgery at all.

On March 28- 29, 2017, the National Cancer Institute (NCI) Thoracic Malignacy Steering Committee, International Association for the Study of Lung Cancer, and Mesothelioma Applied Research Foundation convened the NCI-International Association for the Study of Lung Cancer- Mesothelioma Applied Research Foundation Mesothelioma Clinical Trials Planning Meeting in Bethesda, Maryland. The goal of the meeting was to bring together lead academicians, clinicians, scientists, and the U.S. Food and Drug Administration to focus on the development of clinical trials for patients in whom malignant pleural mesothelioma has been diagnosed. In light of the discovery of new cancer targets affecting the clinical development of novel agents and immunotherapies in malignant mesothelioma, the objective of this meeting was to assemble a consensus on at least two or three practice-changing multimodality clinical trials to be conducted through NCI's National Clinical Trials Network.

Objective Inflammation is a well-known consequence of surgery. Although surgical debulking of tumor is beneficial to patients, the onset of inflammation in injured tissue may impede the success of adjuvant therapies. One marker for postoperative inflammation is IL-6, which is released as a consequence of surgical injuries. IL-6 is predictive of response to many cancer therapies, and it is linked to various molecular and cellular resistance mechanisms. The purpose of this study was to establish a murine model by which therapeutic responses to photodynamic therapy (PDT) can be studied in the context of surgical inflammation. Materials and methods Murine models with AB12 mesothelioma tumors were treated with either surgical resection or sham surgery with tumor incision but no resection. The timing and extent of IL-6 release in the tumor and/or serum was measured using enzyme-linked immunosorbent assay (ELISA) and compared to that measured in the serum of 27 consecutive, prospectively enrolled patients with malignant pleural mesothelioma (MPM) who underwent macroscopic complete resection (MCR). Results MPM patients showed a significant increase in IL-6 at the time MCR was completed. Similarly, IL-6 increased in the tumor and serum of mice treated with surgical resections. However, investigations that combine resection with another therapy make it necessary to grow tumors for resection to a larger volume than those that receive secondary therapy alone. As the larger size may alter tumor biology independent of the effects of surgical injury, we assessed the tumor incision model. In this model, tumor levels of IL-6 significantly increased after tumor incision. Conclusion The tumor incision model induces IL-6 release as is seen in the surgical setting, yet it avoids the limitations of surgical resection models. Potential mechanisms by which surgical induction of inflammation and IL-6 could alter the nature and efficacy of tumor response to PDT are reviewed. These include a wide spectrum of molecular and cellular mechanisms through which surgically-induced IL-6 could change the effectiveness of therapies that are combined with surgery. The tumor incision model can be employed for novel investigations of the effects of surgically-induced, acute inflammation on therapeutic response to PDT (or potentially other therapies). Lasers Surg. Med. 50:440-450, 2018. © 2018 Wiley Periodicals, Inc.

Mesothelioma is a rare cancer of the mesothelial cell layer of the pleura, peritoneum, pericardium and tunica vaginalis. It is typically caused by asbestos, notoriously resistant to chemotherapy and generally considered incurable with a poor life expectancy. Transglutaminase 2 (TG2), a GTP binding regulatory protein, is an important cancer stem cell survival and therapy resistance factor. We show that TG2 is highly expressed in human mesothelioma tumors and in mesothelioma cancer stem cells (MCS cells). TG2 knockdown or TG2 inhibitor treatment reduces MCS cell spheroid formation, matrigel invasion, migration and tumor formation. Time to tumor first appearance is doubled in TG2 knockout cells as compared to wild-type. In addition, TG2 loss is associated with reduced expression of stemness, and epithelial mesenchymal transition markers, and enhanced apoptosis. These studies indicate that TG2 is an important MCS cell survival protein and suggest that TG2 may serve as a mesothelioma cancer stem cell therapy target.

Objectives Hyperthermic pleural lavage with povidone-iodine (PVP-I) is utilized to control micrometastatic disease following cytoreductive surgery for thymic epithelial tumours (TETs). Our objective was to investigate whether PVP-I demonstrates direct cytotoxicity against human TET cells. Methods Human Met-5A (immortalized mesothelial cell), IU-TAB-1 (thymoma) and Ty-82 (thymic carcinoma) cell lines were treated with serial dilutions of PVP-I (0.01-10%) for 5, 30 and 60 min at 37°C and 42°C. MTT assays and flow cytometry were used to evaluate cell death and apoptosis. Membrane permeability was assayed by intracellular staining of cleaved poly-ADP-ribose polymerase. Cellular fixation was evaluated by membrane disruption of dead cells by dimethylsulphoxide and by comparing cleaved poly-ADP-ribose polymerase staining following PVP-I with known fixatives. Results MTT assays demonstrated that PVP-I concentrations greater than 0.5% led to rapid cell death in both TET cell lines regardless of temperature. IC50 values following 5 min of exposure to PVP-I were 8.4 mM (0.3%) and 13.3 mM (0.48%) for IU-TAB-1 and Ty-82, respectively and 8.9 mM (0.32%) for MeT-5A. Flow cytometry demonstrated that 5-min exposure of either cell line to 1% PVP-I resulted in profound cell death: 74% and 58% at 5 min and 97% and 95% at 30 min, for IU-TAB-1 and Ty-82 cells, respectively. Resistance of PVP-I-treated cells to dimethylsulphoxide lysis and similar cleaved poly-ADP-ribose polymerase expression following PVP-I and known fixatives revealed cellular fixation as the mechanism of death following PVP-I exposure. Conclusions PVP-I results in rapid death of human TET cells and normal mesothelial cells through a cellular fixation mechanism and may, therefore, favourably impact the control of micrometastatic disease following resection of TETs with pleural dissemination.