Major response of a peritoneal mesothelioma to nivolumab and ipilimumab: a case report, molecular analysis and review of literature.

Malignant peritoneal mesothelioma (MPM) is a rare tumor associated with a poor prognosis and a lack of consensus regarding treatment strategies. While the Checkmate 743 trial demonstrated the superiority of first-line nivolumab and ipilimumab over chemotherapy in malignant pleural mesothelioma (MPlM), few studies have assessed the effectiveness of immunotherapy against MPM, due to its rarity. Here, we report a major and sustained 12-month response in a 74-year-old female patient who received the anti-PD-1 nivolumab and the anti-CTLA4 ipilimumab as first-line therapy for diffuse MPM. PD-L1 was expressed and BAP1 expression was lost, as shown by immunohistochemistry, however the BAP1 gene was not mutated. Our findings suggest a role for ICI in non-resectable diffuse MPM exhibiting PD-L1 overexpression and loss of BAP1 expression, and instill new hope in their treatment. To our knowledge, this is the second reported case of dual immunotherapy used as first-line in MPM with a major clinical response. To investigate the clinical outcome, we conducted additional molecular analyses of the MPM tumor and we reviewed the literature on immunotherapy in MPM to discuss the role of PD-L1 and BAP1.

Development in the Study of Natural Killer Cells for Malignant Peritoneal Mesothelioma Treatment.

Malignant peritoneal mesothelioma (MPeM) is a rare primary malignant tumor originating from peritoneal mesothelial cells. Insufficient specificity of the symptoms and their frequent reappearance following surgery make it challenging to diagnose, creating a need for more efficient treatment options. Natural killer cells (NK cells) are part of the innate immune system and are classified as lymphoid cells. Under the regulation of activating and inhibiting receptors, NK cells secrete various cytokines to exert cytotoxic effects and participate in antiforeign body, antiviral, and antitumor activities. This review provides a comprehensive summary of the specific alterations observed in NK cells following MPeM treatment, including changes in cell number, subpopulation distribution, active receptors, and cytotoxicity. In addition, we summarize the impact of various therapeutic interventions, such as chemotherapy, immunotherapy, and targeted therapy, on NK cell function post-MPeM treatment.

Sarcomatoid Mesothelioma With New Pancreatic Lesions Presenting As Acute Pancreatitis: A Case Report.

Sarcomatoid mesothelioma is a rare, aggressive malignancy that usually follows asbestos exposure. It is the least common subtype of mesotheliomas, following epithelial and biphasic subtypes. Pleural mesothelioma can metastasize, with the liver, kidneys, adrenal glands, and opposite lungs being the most commonly reported sites for metastasis. Metastasis of the pancreas is extremely rare, which is why the authors of this case report intend to present the case of a 78-year-old male who was found to have acute pancreatitis, most likely secondary to metastatic lesions.

Asbestos Surveillance Program Aachen (ASPA): Cancer mortality among asbestos exposed power industry workers.

BACKGROUND: The time between initial asbestos exposure and asbestos-related disease can span several decades. The Asbestos Surveillance Program aims to detect early asbestos-related diseases in a cohort of 8,565 power industry workers formerly exposed to asbestos. RESEARCH QUESTION: How does asbestos exposure patterns affect cancer mortality and the duration of latency until death? METHODS: A mortality follow-up was conducted with available vital status for 8,476 participants (99 %) and available death certificates for 89.9 % of deceased participants. Standardised mortality ratios (SMR) were calculated for asbestos-related cancers. The SMR of mesothelioma and lung cancer were stratified by exposure duration, cumulative asbestos exposure and smoking. The effect of age at first exposure, cumulative asbestos exposure and smoking on the duration of latency until death was examined using multiple linear regression analysis. RESULTS: The mortality risk of mesothelioma (n = 104) increased with cumulative asbestos exposure but not with exposure duration; the highest mortality (SMR: 23.20; 95 % CI: 17.62-29.99) was observed in participants who performed activities with short extremely high exposures (steam turbine revisions). Lung cancer mortality (n = 215) was not increased (SMR: 1.03; 95 % CI: 0.89-1.17). Median latency until death was 46 (15-63) years for mesothelioma and 44 (15-70) years for lung cancer and deaths occurred between age 64 and 82 years. Latency until death was not influenced by age at first exposure, cumulative exposure, or smoking. CONCLUSION: Cumulative dose seems to be more appropriate than exposure duration for estimating the risk of mesothelioma death. Additionally, exposure with high cumulative doses in short time should be considered. Since only lung cancer mortality, not incidence, was recorded in this study, lung cancer risk associated with asbestos exposure could not be assessed and the lung cancer mortality was lower than expected probably due to screening effects and improved treatments. The critical time window of death from asbestos-related cancer is between the seventh and ninth decade of life. Future studies should further explore the concept of latency, especially since large ranges are reported throughout the literature.

Identification of resistance mechanisms to small-molecule inhibition of TEAD-regulated transcription.

The Hippo tumor suppressor pathway controls transcription by regulating nuclear abundance of YAP and TAZ, which activate transcription with the TEAD1-TEAD4 DNA-binding proteins. Recently, several small-molecule inhibitors of YAP and TEADs have been reported, with some entering clinical trials for different cancers with Hippo pathway deregulation, most notably, mesothelioma. Using genome-wide CRISPR/Cas9 screens we reveal that mutations in genes from the Hippo, MAPK, and JAK-STAT signaling pathways all modulate the response of mesothelioma cell lines to TEAD palmitoylation inhibitors. By exploring gene expression programs of mutant cells, we find that MAPK pathway hyperactivation confers resistance to TEAD inhibition by reinstating expression of a subset of YAP/TAZ target genes. Consistent with this, combined inhibition of TEAD and the MAPK kinase MEK, synergistically blocks proliferation of multiple mesothelioma and lung cancer cell lines and more potently reduces the growth of patient-derived lung cancer xenografts in vivo. Collectively, we reveal mechanisms by which cells can overcome small-molecule inhibition of TEAD palmitoylation and potential strategies to enhance the anti-tumor activity of emerging Hippo pathway targeted therapies.

Chemotherapy increases CDA expression and sensitizes malignant pleural mesothelioma cells to capecitabine treatment.

The combination of cisplatin and pemetrexed remains the gold standard chemotherapy for malignant pleural mesothelioma (MPM), although resistance and poor response pose a significant challenge. Cytidine deaminase (CDA) is a key enzyme in the nucleotide salvage pathway and is involved in the adaptive stress response to chemotherapy. The cytidine analog capecitabine and its metabolite 5'-deoxy-5-fluorocytidine (5'-DFCR) are converted via CDA to 5-fluorouracil, which affects DNA and RNA metabolism. This study investigated a schedule-dependent treatment strategy, proposing that initial chemotherapy induces CDA expression, sensitizing cells to subsequent capecitabine treatment. Basal CDA protein expression was low in different mesothelioma cell lines but increased in the corresponding xenografts. Standard chemotherapy increased CDA protein levels in MPM cells in vitro and in vivo in a schedule-dependent manner. This was associated with epithelial-to-mesenchymal transition and with HIF-1alpha expression at the transcriptional level. In addition, pretreatment with cisplatin and pemetrexed in combination sensitized MPM xenografts to capecitabine. Analysis of a tissue microarray (TMA) consisting of samples from 98 human MPM patients revealed that most human MPM samples had negative CDA expression. While survival curves based on CDA expression in matched samples clearly separated, significance was not reached due to the limited sample size. In non-matched samples, CDA expression before but not after neoadjuvant therapy was significantly associated with worse overall survival. In conclusion, chemotherapy increases CDA expression in xenografts, which is consistent with our in vitro results in MPM and lung cancer. A subset of matched patient samples showed increased CDA expression after therapy, suggesting that a schedule-dependent treatment strategy based on chemotherapy and capecitabine may benefit a selected MPM patient population.

Peritoneal Dissemination in Patients with Recurrence After Post-pleurectomy/decortication for Pleural Mesothelioma.

BACKGROUND: In clinical practice, peritoneal dissemination after curative-intent surgery for pleural mesothelioma occasionally recurs. This study investigated the risk factors and prognosis associated with post-pleurectomy/decortication peritoneal dissemination in pleural mesothelioma, which are rarely reported. METHODS: This retrospective review included 160 patients who experienced recurrence after pleurectomy/decortication for pleural mesothelioma between January 2011 and December 2021. Patients with recurrence were classified according to the initial recurrence pattern. The P group experienced recurrence with peritoneal dissemination, and the non-P group experienced recurrence without peritoneal dissemination. The analysis determined the risk factors for peritoneal dissemination using multivariable logistic regression analysis. Survival was analyzed using the Kaplan-Meier method and the log-rank test. RESULTS: Of the 160 patients, 20 (12.5%) exhibited peritoneal dissemination and were assigned to the P group, whereas 140 (87.5%) had recurrence without peritoneal dissemination and were assigned to the non-P group. Multivariable logistic regression analysis showed that diaphragm reconstruction (odds ratio [OR], 2.8; 95% confidence interval [CI], 1.0-8.0; p = 0.048) and female sex (OR, 3.7; 95% CI 1.26-10.8; p = 0.017) were associated with the P group. Post-recurrence survival was worse in the P group than in the non-P group (1-year post-recurrence survival: 22.2% vs. 65.3%; median: 6.7 months vs. 19.4 months; p = 0.0013). CONCLUSIONS: Peritoneal dissemination occurred in approximately one of every eight patients with recurrence after pleurectomy/decortication for pleural mesothelioma, and the incidence was significantly higher among females and patients undergoing diaphragm reconstruction. Moreover, postoperative recurrence of peritoneal dissemination was associated with a poor prognosis.

[Erionite, an exposure factor linked to pleural mesothelioma]. / L'érionite, un facteur expositionnel lié au mésothéliome pleural.

Mesotheliomas are neoplasia developed from the mesothelium, a layer covering the viscera (visceral layer) and the cavity where the organs are (parietal layer). The best known, and the most frequently encountered is the pleural mesothelioma. This disease has a close link with exposure to asbestos, a mineral fibre now banned in several countries. However, other exposure factors have also been incriminated, including another one recognised as a certain carcinogenic agent for several years now : erionite. We present the case of a patient with pleural mesothelioma whose exposure to erionite could be demonstrated. The presentation of this clinical case will be complemented by a literature review on this less known and mostly environmental exposure, contrary to asbestos which is mostly professional.

Les mésothéliomes sont des néoplasies se développant à partir du mésothélium, feuillet recouvrant, d'une part, les viscères (feuillet viscéral) et, d'autre part, la cavité où se trouvent les organes (feuillet pariétal). Le plus connu, et le plus fréquemment rencontré, est le mésothéliome pleural. Cette maladie a un lien étroit avec l'exposition à l'amiante, fibre minérale maintenant interdite dans plusieurs pays. Cependant, d'autres facteurs expositionnels ont également été incriminés, dont un autre reconnu comme cancérogène certain depuis plusieurs années : l'érionite. Nous présentons le cas d'un patient atteint d'un mésothéliome pleural pour lequel une exposition à l'érionite a pu être étayée. La présentation du cas clinique sera complétée d'une revue de la littérature sur cette exposition particulière moins connue et majoritairement environnementale, contrairement à l'amiante dont l'exposition est majoritairement professionnelle.

[Malignant mesothelioma of the vaginal testis: diagnostic and therapeutic considerations]. / Le mésothéliome malin de la vaginale testiculaire : aspects diagnostiques et thérapeutiques.

Mesothelioma of the testicular vagina is a rare malignant tumour, most often discovered by chance. The rarity of this type of tumour has not led to the development of specific guidelines. Median survival is estimated at 30 months. The lack of data and official recommendations makes surgical and medical management and follow-up difficult. Men who have not undergone radical orchiectomy die very rapidly after diagnosis. The remission rate at 1 year post-orchidectomy is 47 %, the recurrence rate at 1 year is 53 % and 92 % of relapses occur within 5 years post-operatively. The treatment option of hemiscrotectomy in the first instance has rarely been used; a second-look resection with negative margins may be proposed. The usefulness of adjuvant chemotherapy and/or radiotherapy has not been clearly demonstrated. Local recurrence is accompanied by metastasis in 85 % of cases. In the case of metastatic cancer (15 %), the retro-peritoneal, inguinal and iliac lymph nodes may be invaded. Follow-up by injected thoraco-abdomino-pelvic CT scan is recommended every 3 months for 2 years, then once a year for 3 years, for a total of 5 years of close follow-up. The long-term recurrence rate is 3 %.

Le mésothéliome de la vaginale testiculaire est une tumeur maligne rare et souvent de découverte fortuite. Sa rareté d'apparition n'a pas permis de développer des recommandations spécifiques. La survie médiane est estimée à 30 mois. Le manque de recommandations officielles rend sa prise en charge chirurgicale, médicale et son suivi difficiles. Les hommes n'ayant pas bénéficié d'orchidectomie radicale décèdent très rapidement après le diagnostic. Le taux de rémission à 1 an post-orchidectomie est de 47 %, le taux de récurrence à 1 an est de 53 % et 92 % des rechutes se font endéans les 5 ans post-opératoires. L'option thérapeutique par hémi-scrotectomie en première intention a rarement été pratiquée, une résection de «second look¼ en marges saines peut être proposée. L'utilité d'une chimiothérapie et/ou d'une radiothérapie adjuvante n'a pas été clairement démontrée. Une rechute locale est accompagnée de métastases dans 85 % des cas. En cas de cancer d'emblée métastatique (15 %), les relais ganglionnaires rétro-péritonéaux, inguinaux et iliaques peuvent être envahis. Un suivi par scanner thoraco-abdomino-pelvien injecté est recommandé tous les 3 mois pendant 2 ans, puis 1 fois par an pendant 3 ans pour un total de 5 ans. Le taux de récidive au long cours est de 3 %.

Are there features that can predict the unresectability of pleural mesothelioma?

INTRODUCTION: The current clinical staging of pleural mesothelioma (PM) is often discordant with the pathologic staging. This study aimed to identify clinical and radiological features that could help predict unresectability in PM. METHODS: Twenty-two descriptive radiologic features were retrospectively evaluated on preoperative computed tomography (CT) and/or positron emission tomography/CT (PET/CT) performed in patients with presumably resectable PM who underwent surgery. Measurements of maximum and sum pleural thickness at three levels of the thorax (upper, middle, and lower) were taken and stratified based on the cutpoints provided by the International Association for the Study of Lung Cancer (IASLC). Clinical and radiological features, including clinical-stage, were compared between resectable and unresectable tumors by univariate analysis and logistic regression modeling. RESULTS: Of 133 patients, 69/133 (52%) had resectable and 64/133 (48%) had unresectable PM. Asbestos exposure (p = 0.005), neoadjuvant treatment (p = 0.001), clinical T-stage (p < 0.0001), all pleural thickness measurements (p < 0.05), pleural thickness pattern (p < 0.0001) and degree (p = 0.033), lung invasion (p = 0.004), extrapleural space obliteration (p < 0.0001), extension to subphrenic space (p = 0.0004), and two combination variables representing extensive diaphragmatic contact and/or chest wall involvement (p = 0.002) and mediastinal invasion (p < 0.0001) were significant predictors at univariate analysis. At multivariable analysis, all models achieved a strong diagnostic performance (area under the curve (AUC) > 0.8). The two best-performing models were one that included the upper-level maximum pleural thickness, extrapleural space obliteration, and mediastinal infiltration (AUC = 0.876), and another that integrated clinical variables and radiological assessment through the clinical T-stage (AUC = 0.879). CONCLUSION: Selected clinical and radiologic features, including pleural thickness measurements, appear to be strong predictors of unresectability in PM. CLINICAL RELEVANCE STATEMENT: A more accurate prediction of unresectability in the preoperative assessment of patients with pleural mesothelioma may avoid unnecessary surgery and prompt initiation of nonsurgical treatments. KEY POINTS: About half of pleural mesothelioma patients are reported to receive an incorrect disease stage preoperatively. Eleven features identified as predictors of unresectability were included in strongly performing predictive models. More accurate preoperative staging will help clinicians and patients choose the most appropriate treatments.

Case report: ATM A1159T mutation in malignant peritoneal mesothelioma may be associated with tumor recurrence.

Malignant peritoneal mesothelioma is an exceedingly rare malignant tumor. Herein, we present a case of malignant peritoneal mesothelioma in a 59-year-old Chinese female patient who was stable after treatment for multiple relapses. Imaging revealed massive ascites and an irregular thickening of the peritoneal mesangium. Laparoscopic biopsy revealed heterogeneous cell nests in the parietal peritoneal fibrous tissue, which were confirmed by immunohistochemical staining for Calretinin, WT-1, and D2-40. In terms of genetic screening, BAP1, CSF1R, and other key driver gene variants closely related to malignant peritoneal mesothelioma have been explored in tumor tissues. Notably, CARD11 driver mutation was first found in all malignant peritoneal mesothelioma patients, and ATM A1159T gene mutation found in recurrent focal tissue may be associated with recurrent tumor recurrence.

Primary extraskeletal osteosarcomas of the pleura: A clinicopathological, immunohistochemical, and molecular analysis of 4 cases.

Four primary extraskeletal osteosarcomas of the pleura are presented. The patients were men between the ages of 63 and 78 years (average: 70.5 years) who presented with symptoms of chest pain, cough, and shortness of breath. Diagnostic imaging showed variably calcified, pleural-based masses and/or diffuse pleural thickening, clinically mimicking mesothelioma. Thoracoscopic surgical material was obtained for histopathological diagnosis. Histological findings showed the presence of a neoplastic spindle cell proliferation composed of fusiform cells with scant cytoplasm, elongated nuclei and inconspicuous nucleoli. Mitotic activity was easily identified. Additionally, all tumors showed extensive osseous differentiation in the form of osteoid matrix production; one tumor demonstrated additional chondrosarcomatous elements and another showed focal myxoid changes. Immunohistochemical analysis revealed that the tumor cells were uniformly negative for a wide variety of antibodies, including keratin AE1/AE3, keratin 5/6, D2-40, EMA, calretinin, WT-1, BerEP4, and HEG1; BAP1 was retained in all cases. In addition, fluorescence in situ hybridization for CDKN2A (p16) was negative for homozygous deletion in all tumors. Clinical follow-up showed that one patient had died 8 months after diagnosis and one had remained alive with short post-diagnostic follow-up. The tumors herein described highlight a challenging issue in the separation of mesothelioma with heterologous elements from true osteosarcomas of pleural origin. We propose that a diagnosis of extraskeletal osteosarcoma of the pleura is rendered for tumors with malignant osseous and/or cartilaginous differentiation in which comprehensive immunohistochemical studies and FISH analysis have failed to provide support for a diagnosis of mesothelioma with heterologous elements.

Primary Intrahepatic Mesothelioma: Case Series and Systematic Review of Literature.

BACKGROUND: Primary intrahepatic mesothelioma (PIHMM) has been rarely reported. Its typical clinical presentation, radiological features and pathology have not been defined. Here, we aimed to summarize its diagnosis and treatment. METHODS: We conducted a retrospective analysis of three cases of PIHMM in the First Affiliated Hospital of Zhejiang University School of Medicine and reviewed the current literature to investigate the clinical and pathological characteristics and prognosis of PIHMM. RESULTS: Based on our case series and the literature, the mean age of PIHMM was 59.7 (41-83) years. Most patients present with nonspecific symptoms such as abdominal pain, fever, weight loss and weakness. On imaging, PIHMM usually presented as a solid, heterogeneous soft tissue mass with irregular margins and significant enhancement of the margins in the arterial phase. Immunohistochemical markers such as calretinin, cytokeratin (CK)5/6, D2-40, WT-1, mesothelin CK and vimentin may be useful for diagnosis. The 3-year relapse-free survival rate (RFS) was 51.85%, the 3-year overall survival (OS) rate was 83.33% and the 3-year postoperative overall survival rate was 100%. CONCLUSION: PIHMM can only be diagnosed by careful postoperative pathology, because of its nonspecific clinical presentations, serological indicators or imaging features. Immunohistochemical staining is very useful to distinguish this tumor from other liver tumors. Surgery is the mainstay of treatment.

Unleashing precision: A review of targeted approaches in pleural mesothelioma.

This review delves into the intricate landscape of pleural mesothelioma (PM), emphasizing the need for nuanced therapeutic strategies. While platinum-based chemotherapy remains a cornerstone, the advent of immune checkpoint inhibitors (ICIs), notably through the Checkmate 743 trial, has reshaped treatment paradigms. Challenges persist due to patient heterogeneity and a lack of specific biomarkers. Targeting genotypic and phenotypic alterations emerges as a promising avenue, demanding precision oncology in this rare disease. CDKN2A loss, prevalent in PM, may respond to CDK4/6 inhibitors. Defects in MMR and HR suggest tailored approaches with ICI or PARP inhibitors, respectively. Ongoing trials explore novel inhibitors and promising targets like mesothelin. Implementing these strategies requires overcoming challenges in patient selection, combination therapies, biomarker identification, and cost considerations. Collaboration is crucial for transforming these insights into impactful clinical interventions, heralding the era of personalized and precision medicine for PM.

Volatile Organic Compound Analysis of Malignant Pleural Mesothelioma Chorioallantoic Membrane Xenografts.

Malignant pleural mesothelioma (MPM) is an aggressive cancer associated with asbestos exposure. MPM is often diagnosed late, at a point where limited treatment options are available, but early intervention could the chances of successful treatment for MPM patients. Biomarkers to detect MPM in at-risk individuals are needed to implement early diagnosis technologies. Volatile organic compounds (VOCs) have previously shown diagnostic potential as biomarkers when analysed in MPM patient breath. In this study, chorioallantoic membrane (CAM) xenografts of MPM cell lines were used as models of MPM tumour development for VOC biomarker discovery with the aim of generating targets for investigation in breath, biopsies or other complex matrices. VOC headspace analysis of biphasic MESO-7T, epithelioid MESO-8T and MESO-12T MPM CAM xenografts was performed using solid-phase microextraction and gas chromatography-mass spectrometry. We successfully demonstrated the capture, analysis and separation of VOC signatures from CAM xenografts and controls. A panel of VOCs was identified that showed discrimination between MPM xenografts generated from biphasic and epithelioid cells and CAM controls. This is the first application of the CAM xenograft model for the discovery of VOC biomarkers associated with MPM histological subtypes. These findings support the potential utility of non-invasive VOC profiling from breath or headspace analysis of tissues for detection and monitoring of MPM.

Isolation and whole genomic analysis of mesophilic bacterium Pseudoglutamicibacter cumminsii in epithelial mesothelioma.

The relationship between bacteria and tumors has been the hot spot of clinical research in recent years. Pseudoglutamicibacter cumminsii is an aerobic Gram-positive bacterium commonly found in soil. Recent studies have identified P. cumminsii in patients with cutaneous and urinary tract infections. However, little is known on its pathogenesis as well as involvement in other clinical symptoms. In this study, we first report the isolation of P. cumminsii in blood of an epithelial mesothelioma patient. The clinical and laboratory characteristics of P. cumminsii were first described and evaluated. The pure colony of P. cumminsii was then identified using automated microorganism identification system and mass spectrum. The whole genome of the newly identified strain was sequenced with third generation sequencing (TGS). The assembled genome was further annotated and analyzed. Whole genomic and comparative genomic analysis revealed that the isolated P. cumminsii strain in this study had a genome size of 2,179,930 bp and had considerable unique genes compared with strains reported in previous findings. Further phylogenetic analysis showed that this strain had divergent phylogenetic relationship with other P. cumminsii strains. Based on these results, the newly found P. cumminsii strain was named P. cumminsii XJ001 (PC1). Virulence analysis identified a total of 71 pathogenic genes with potential roles in adherence, immune modulation, nutrition/metabolism, and regulation in PC1. Functional analysis demonstrated that the annotated genes in PC1 were mainly clustered into amino acid metabolism (168 genes), carbohydrate metabolism (107 genes), cofactor and vitamin metabolisms (98 genes), and energy metabolism (68 genes). Specifically, six genes including yodJ, idh, katA, pyk, sodA, and glsA were identified within cancer pathways, and their corresponding homologous genes have been documented with precise roles in human cancer. Collectively, the above results first identified P. cumminsii in the blood of tumor patients and further provide whole genomic landscape of the newly identified PC1 strain, shedding light on future studies of bacteria in tumorigenesis.

Lung cancer (internet-based) Delphi (LUCiD): A modified eDelphi consensus process to establish Australasian clinical quality indicators for thoracic cancer.

BACKGROUND AND OBJECTIVE: Approximately 16,000 new cases of lung cancer are diagnosed each year in Australia and Aotearoa New Zealand, and it is the leading cause of cancer death in the region. Unwarranted variation in lung cancer care and outcomes has been described for many years, although clinical quality indicators to facilitate benchmarking across Australasia have not been established. The purpose of this study was to establish clinical quality indicators applicable to lung and other thoracic cancers across Australia and Aotearoa New Zealand. METHODS: Following a literature review, a modified three round eDelphi consensus process was completed between October 2022 and June 2023. Participants included clinicians from all relevant disciplines, patient advocates, researchers and other stakeholders, with representatives from all Australian states and territories and Aotearoa New Zealand. Consensus was set at a threshold of 70%, with the first two rounds conducted as online surveys, and the final round held as a hybrid in person and virtual consensus meeting. RESULTS: The literature review identified 422 international thoracic oncology indicators, and a total of 71 indicators were evaluated over the course of the Delphi consensus. Ultimately, 27 clinical quality indicators reached consensus, covering the continuum of thoracic oncologic care from diagnosis to first line treatment. Indicators benchmarking supportive care were poorly represented. Attendant numeric quality standards were developed to facilitate benchmarking. CONCLUSION: Twenty-seven clinical quality indicators relevant to thoracic oncology care in Australasia were developed. Real world implementation will now be explored utilizing a prospective dataset collected across Australia.

Outcome prediction based on [18F]FDG PET/CT in patients with pleural mesothelioma treated with ipilimumab and nivolumab +/- UV1 telomerase vaccine.

PURPOSE: The introduction of immunotherapy in pleural mesothelioma (PM) has highlighted the need for effective outcome predictors. This study explores the role of [18F]FDG PET/CT in predicting outcomes in PM treated with immunotherapy. METHODS: Patients from the NIPU trial, receiving ipilimumab and nivolumab +/- telomerase vaccine in second-line, were included. [18F]FDG PET/CT was obtained at baseline (n = 100) and at week-5 (n = 76). Metabolic tumour volume (MTV) and peak standardised uptake value (SUVpeak) were evaluated in relation to survival outcomes. Wilcoxon rank-sum test was used to assess differences in MTV, total lesion glycolysis (TLG), maximum standardised uptake value (SUVmax) and SUVpeak between patients exhibiting an objective response, defined as either partial response or complete response according to the modified Response Criteria in Solid Tumours (mRECIST) and immune RECIST (iRECIST), and non-responders, defined as either stable disease or progressive disease as their best overall response. RESULTS: Univariate Cox regression revealed significant associations of MTV with OS (HR 1.36, CI: 1.14, 1.62, p < 0.001) and PFS (HR 1.18, CI: 1.03, 1.34, p = 0.02), while multivariate analysis showed a significant association with OS only (HR 1.35, CI: 1.09, 1.68, p = 0.007). While SUVpeak was not significantly associated with OS or PFS in univariate analyses, it was significantly associated with OS in multivariate analysis (HR 0.43, CI: 0.23, 0.80, p = 0.008). Objective responders had significant reductions in TLG, SUVmax and SUVpeak at week-5. CONCLUSION: MTV provides prognostic value in PM treated with immunotherapy. High SUVpeak was not associated with inferior outcomes, which could be attributed to the distinct mechanisms of immunotherapy. Early reductions in PET metrics correlated with treatment response. STUDY REGISTRATION: The NIPU trial (NCT04300244) is registered at clinicaltrials.gov. https://classic. CLINICALTRIALS: gov/ct2/show/NCT04300244?cond=Pleural+Mesothelioma&cntry=NO&draw=2&rank=4.