Environmental asbestos exposure and lung cancer.

Apart from living near an asbestos industry site, mine, or in an asbestos-contaminated house, environmental asbestos exposure is observed in certain regions where the (natural) soil is 'contaminated' with asbestos (fibers). In this essay, we review the association between environmental asbestos exposure and lung cancer in Turkey. Other studies have also suggested that environmental asbestos exposure is able to increase the risk of lung cancer. Lung cancer associated with environmental asbestos exposure seems to be diagnosed at a younger age, and the risk for women is in the same range as that for men. Our data indicate that the relationship between exposure dose and risk is linear and that a safe threshold cannot be established. Therefore, people living in areas with increased chances of environmental asbestos exposure should be mentored to take part in smoking cessation programs and considered candidates for inclusion in lung cancer screening programs. There is an obvious need for additional studies on this topic.

Image-Assisted Pleural Needle Biopsy or Medical Thoracoscopy: Which Method for Which Patient? A Randomized Controlled Trial.

BACKGROUND: Image-guided or assisted needle biopsies and the increasing use of medical thoracoscopy (MT) have increased the diagnostic accuracy of pleural diseases significantly. However, no consensus exists regarding which patients with pleural effusion should undergo MT and which patients should undergo image-guided or assisted needle biopsy as the first procedure to ensure greater diagnostic accuracy. RESEARCH QUESTION: Which biopsy method is more appropriate for which patient to provide the highest diagnostic accuracy in the diagnosis of pleural effusion? STUDY DESIGN AND METHODS: This prospective, randomized, parallel study included 228 patients with undiagnosed exudative pleural effusion. Patients were divided into two groups based on CT scan findings. Group 1 included patients with pleural effusion only. Group 2 included patients with pleural thickening or lesion in addition to pleural effusion. Patients in each group were assigned randomly to an image-assisted Abrams needle pleural biopsy (IA-ANPB) or MT arm. The diagnostic sensitivity, reliability, and safety were determined for both groups. RESULTS: The false-negative rate was 30.3% for the IA-ANPB arm and 3.1% for the MT arm in group 1. The same rates were 11.9% for IA-ANPB and 4.7% for MT in group 2. In group 1, the sensitivity for the IA-ANPB arm was 69.7%, and the negative likelihood ratio was 0.30. The same rates for the MT arm were 96.9% and 0.03 (P = .009). In group 2, these values were 88.1% and 0.12 for the IA-ANPB arm and 95.4% and 0.05 for the MT arm (P = .207). The rate of complications between the two biopsy methods was not different (8.5% and 15.8%, respectively; P = .107). INTERPRETATION: MT showed a high diagnostic success in all patients with pleural fluid. However, IA-ANPB showed similar diagnostic success as MT in patients with pleural effusion and associated pleural thickening or lesions. Therefore, in the latter case, IA-ANPB could be preferable to MT. TRIAL REGISTRY: ClinicalTrials.gov; No.: NCT05428891; URL: www. CLINICALTRIALS: gov.

Complex Genomic Rearrangement Patterns in Malignant Pleural Mesothelioma due to Environmental Asbestos Exposure.

Malignant pleural mesothelioma (MPM) is a rare type of cancer, and its main risk factor is exposure to asbestos. Accordingly, our knowledge of the genomic structure of an MPM tumor is limited when compared to other cancers. In this study, we aimed to characterize complex genomic rearrangement patterns and variations to better understand the genomics of MPM tumors. We comparatively scanned 3 MPM tumor genomes by Whole-Genome Sequencing and High-Resolution SNP array. We also used various computational algorithms to detect both CNAs and complex chromosomal rearrangements. Genomic data obtained from each bioinformatics tool are interpreted comparatively to better understand CNAs and cancer-related Nucleotide variations in MPM tumors. In patients 1 and 2, we found pathogenic nucleotide variants of BAP1, RB1, and TP53. These two MPM genomes exhibited a highly rearranged chromosomal rearrangement pattern resembling Chromomanagesis particularly in the form of Chromoanasynthesis. In patient 3, we found nucleotide variants of important cancer-related genes, including TGFBR1, KMT2C, and PALLD, to have lower chromosomal rearrangement complexity compared with patients 1 and 2. We also detected several actionable nucleotide variants including XRCC1, ERCC2. We also discovered the SKA3-DDX10 fusion in two MPM genomes, which is a novel finding for MPM. We found that MPM genomes are very complex, suggesting that this highly rearranged pattern is strongly related to driver mutational status like BAP1, TP53 and RB1.

BAP1, Wilms' tumor 1, and calretinin in predicting survival and response to first-line chemotherapy in patients with pleural mesothelioma.

PURPOSE: There are currently no methods to predict response to chemotherapy in pleural mesothelioma (PM). The aim of this study is to investigate the predictive and prognostic role of BAP1, WT1 and calretinin expression and their combinations in pre-treatment tumor samples by immunohistochemical (IHC) staining. METHODS: The study included consecutive PM patients treated with chemotherapy alone at a University hospital between 2009 and 2020. BAP1 analyses were performed on formalin-fixed, paraffin-embedded tumor tissue samples of the patients, while WT1 and calretinin information were obtained from the histopathological diagnosis records. RESULTS: Of the total 107 patients included, 64% had loss of BAP1 expression, whereas 77% had WT1 and 86% had calretinin expression. Patients with the presence of BAP1 expression, one or both of the other two markers, or loss of expression of all three markers (unfavorable status) were more likely to not respond to chemotherapy than those with the presence of all three markers or loss of BAP1 expression and expression of one or two other markers (favorable status) (p = 0.001). Median survival time of patients with favorable and unfavorable status was 15 ± 1.7 and 8.0 ± 2.4 months, respectively (p = 0.027). After adjustment for histopathology and stage, loss of BAP1 (HR = 0.54, 95%CI 0.35-0.83), WT1 (1.75, 1.06-2.90), calretinin (2.09, 1.14-3.84) expression and favourable panel (0.50, 0.27-0.92) was associated with prognosis. CONCLUSIONS: The IHC biomarkers BAP1, WT1, and calretinin, used in the routine diagnosis of PM and their combinations, are the first biomarkers associated with response to chemotherapy and may be a useful tool to select patients for first-line platinum pemetrexed treatment in PM patients. Validation in a large cohort is ongoing.

Investigation of MTAP and BAP1 staining loss and P16/CDKN2A deletion in pleural cytology specimens and its role in the diagnosis of mesothelioma.

BACKGROUND: Mesothelioma is a malignant neoplasm with a poor survival rate. We aimed to investigate the importance of BAP1, MTAP (IHC), and p16/CDKN2A homozygous deletion (FISH) in cytologic material obtained from pleural effusion sampling, which is a less invasive procedure in the diagnosis of mesothelioma. METHODS: Our study discussed pleural cytology samples of cases with histopathologically proven mesothelioma diagnoses between 2017 and 2022. As the control group, materials that had pleural effusion sampling for other reasons and reactive mesothelial hyperplasia were included in the study. Cell blocks prepared from these materials were subjected to fluorescent in situ hybridization for p16/CDKN2A homozygous deletion and immunohistochemistry for BAP1 and MTAP. RESULTS: The specificity of the P16/CDKN2A homozygous deletion in diagnosing mesothelioma is 100%. Its sensitivity is 68.75%. The specificity of BAP1 immunohistochemical nuclear expression loss is 95%, while the sensitivity is 60%. Loss of nuclear expression of MTAP alone has the lowest specificity and sensitivity, with a specificity of 86% and a sensitivity of 43%. The highest sensitivity is reached when BAP1 loss and p16/CDKN2A homozygous deletion are evaluated together, increasing to 81%. The specificity is 95%. CONCLUSION: It has been determined that any marker alone cannot be used for a definitive mesothelioma diagnosis in pleural effusion cytological specimens; however, sensitivity increases in some combinations. The combination of BAP1 immunohistochemistry and p16/CDKN2A homozygous deletion detected by FISH, which has a higher specificity and sensitivity, can be routinely used in the diagnosis of mesothelioma under the guidance of clinical and radiologic information.

Longitudinal monitoring of response to chemotherapy in patients with malignant pleural mesothelioma by biomarkers.

BACKGROUND: The aim of the study was to longitudinally investigate the serum levels of mesothelin, sestrin1, hyaluronan synthase 2 (HAS2), midkine, and high mobility group box 1 (HMGB1) before and after chemotherapy and at the time of relapse in malignant pleural mesothelioma (MPM) patients treated with chemotherapy and to compare the changes in biomarker levels with radiological treatment outcome. METHODS: A total of 64 MPM patients treated with chemotherapy were enrolled in the study and longitudinally followed for changes in biomarker levels in response to treatment. Biomarkers levels were measured in serum using a human ELISA kit. Relative and absolute changes in biomarker levels were compared with the best radiological overall response at each time point. RESULTS: Median survival was 20.0 ± 2.4 (15.3-24.7) months in patients with partial and complete response, 17.0 ± 1.0 (15.0-19.0) months in patients with stable disease, and 9.0 ± 1.0 (7.0-11.0) months in patients with progressive disease. A significant decrease in serum levels of mesothelin, midkine, and HMGB1 was observed in patients with radiologically partial and complete responses to chemotherapy (p< 0.001, p= 0.016, and p= 0.039, respectively). In these patients, mesothelin levels decreased by 15%, midkine levels by 7%, and HMGB1 levels by 15%. In addition, HMGB1 serum levels were found to significantly increase by 15% in patients with radiologically progressive responses to chemotherapy compared to pretreatment serum levels (p= 0.035). In patients with partial and complete response to chemotherapy, mesothelin levels increased by 15%, midkine by 12%, and sestrin1 by 8% when the disease recurred (p= 0.004, p= 0.004 and p= 0.044, respectively). CONCLUSION: Biomarkers may be useful in the longitudinal monitoring of response to treatment in MPM. However, the results of our study should be validated in larger groups with sufficient case numbers from multicenter institutions.

Prognostic value of midkine, syndecan-1, hyaluronan synthase-2, sestrin-1, laminin subunit alpha-4 and fibulin-3 for malignant pleural mesothelioma.

Introduction: The prognosis of malignant pleural mesothelioma (MPM) is poor, with a limited survival time. In this study, we aimed to examine expression levels of genes selected from relevant literature and to utilize in silico methods to determine genes whose expression could reflect the prognosis of patients with MPM by ex-vivo validation experiments. Material and methods: The study group consisted of 54 MPM patients treated with chemotherapy. Expression of 6 genes - midkine (MDK), syndecan-1 (SDC1), hyaluronan synthase-2 (HAS2), sestrin-1 (SESN1), laminin subunit alpha-4 (LAMA4), and fibulin-3 (FBLN3) - was examined by qPCR in tumor tissues. Sestrin-1 and LAMA4 were identified using an in house R-based script: Unsupervised Survival Analysis Tool. Midkine, SDC1, HAS2, and FBLN3 were selected from current literature. We used two housekeeping genes, i.e. glucose-6-phosphate dehydrogenase and TATA-box binding protein, as controls. Results: Of the patients, 43 (79.6%) had epithelioid mesothelioma. The median survival for all patients was 10 (±1.2 SE) months (95% CI: 7.7-12.3). In multivariate analyses, MDK (p = 0.007), HAS2 (p = 0.008) and SESN1 (p = 0.014) expression levels were related to survival time in the whole group. In epithelioid type MPM patients, MDK (p = 0.014), FBLN3 (p = 0.029), HAS2 (p = 0.014) and SESN1 (p = 0.045) expression was related to survival time in multivariate analyses. Conclusions: High HAS2 and SESN1 expressions and low MDK are potential biomarkers of good prognosis in MPM. High HAS2 and SESN1 expression and low MDK and FBLN3 can also be utilized as biomarkers of good prognosis for epithelioid MPM. Those results should be further investigated in sera, plasma, and pleural effusions.

Genetic analysis of familial predisposition in the pathogenesis of malignant pleural mesothelioma.

PURPOSE: Mesothelioma is the primary tumor of the mesothelial cell membrane. The most important etiology is asbestos exposure. The development of malignant mesothelioma in very few of the population exposed to asbestos and its frequent occurrence in some families may be significant in terms of genetic predisposition. Again, the presence of relatives with mesothelioma who did not have asbestos contact strengthens this argument. This disease, which has limited treatment options and has a poor prognosis, revealing a genetic predisposition, if any, may prolong survival with early diagnosis and effective treatment. METHODS: Based on the genetic predisposition idea, we diagnosed and followed a total of ten individuals of relatives with mesothelioma. DNA was isolated from peripheral blood and whole genome sequencing analysis was done. Common gene mutations in ten individuals were filtered using bioinformatics. After this filter, from the remaining variants, very rare in the population and damaging mutations are selected. RESULTS: Eight thousand six hundred and twenty-two common variants have been identified in ten individuals with this analysis. In total, 120 variants were found on 37 genes in 15 chromosomes. These genes are PIK3R4, SLC25A5, ITGB6, PLK2, RAD17, HLA-B, HLA-DRB1, HLA-DQB1, GRM, IL20RA, MAP3K7, RIPK2, and MUC16. CONCLUSION: Our finding, PIK3R4 gene, is directly associated with mesothelioma development. Twelve genes, which are associated with cancer, were detected in literature. Additional studies, which scan first-degree relatives of individual, are needed to find the specific gene region.

Gene Variations of Chemokine and Chemokine Receptor CXCL12/CXCR4 in Lung Cancer.

Lung cancer is the most common type of cancer in the world and about 1 million people die from lung cancer every year in the world. Inflammation is an important factor in the onset, progression and metastasis of lung cancer. The most important regulators of inflammation are chemokines and chemokine receptors. Chemokines induce the proliferation of cancer cells and prevent their apoptosis. Chemokines may indirectly affect tumor growth by inducing growth and release of angiogenic factors from cells in the tumor microenvironment. CXCL12/CXCR4 are chemokine and chemokine receptors predicted to be involved in lung cancer pathogenesis. This study aimed to determine the relationship between CXCL12/CXCR4 gene variations and CXCL12 serum levels in disease pathogenesis in lung cancer. For this purpose, DNA samples isolated from 90 lung cancer patients (36 squamous cell carcinomas, 18 small cell carcinomas and 36 adenocarcinomas) and 90 control individuals were genotyped by PCR-RFLP method for CXCL12 (rs1801157) and CXCR4 (rs2228014). CXCL12 protein levels were determined from serum samples by the enzyme-linked immuno-sorbent assay (ELISA) method. Results were evaluated using IBM SPSS Statistics 21 software and FINNETI program. As a result, there was no significant difference between the genotype frequencies of the CXCL12 rs1801157 variant and the risk of lung cancer (P = 0.396). CXCR4 rs2228014 genotypes were significantly associated with lung cancer risk (P < 0.001). Lung cancer patients had significantly elevated serum CXCL12 levels than controls (P < 0.001). In conclusion, the rs2228014 variants localized on the chemokine receptors CXCR4 gene was found to be closely related to lung cancer risk.

Evaluation of Exudative Pleural Effusions: A Multicenter, Prospective, Observational Study.

PURPOSE: The aim of this study is to determine the diagnostic performances of pleural procedures in undiagnosed exudative pleural effusions and to evaluate factors suggestive of benign or malignant pleural effusions in tertiary care centers. METHODS: This was a multicenter prospective observational study conducted between January 1 and December 31, 2018. A total of 777 patients with undiagnosed exudative pleural effusion after the initial work-up were evaluated. The results of diagnostic procedures and the patients' diagnoses were prospectively recorded. Sensitivity, specificity, and accuracy estimates with 95% confidence intervals were used to examine the performance of pleural procedures to detect malignancy. RESULTS: The mean age ± SD of the 777 patients was 62.0 ± 16.0 years, and 68.3% of them were male. The most common cause was malignancy (38.3%). Lung cancer was the leading cause of malignant pleural effusions (20.2%). The diagnostic sensitivity and accuracy of cytology were 59.5% and 84.3%, respectively. The diagnostic sensitivity of image-guided pleural biopsy was 86.4%. The addition of image-guided pleural biopsy to cytology increased diagnostic sensitivity to more than 90%. Thoracoscopic biopsy provided the highest diagnostic sensitivity (94.3%). The highest diagnostic sensitivity of cytology was determined in metastatic pleural effusion from breast cancer (86.7%). CONCLUSION: The diagnostic performance increases considerably when cytology is combined with image-guided pleural biopsy in malignant pleural effusions. However, to avoid unnecessary interventions and complications, the development of criteria to distinguish patients with benign pleural effusions is as important as the identification of patients with malignant pleural effusions.

Serum Expression Levels of Certain miRNAs in Predicting Diagnosis, Prognosis, and Response to Chemotherapy in Malignant Pleural Mesothelioma

Background: miRNAs are involved in tumor pathogenesis and can therefore be determined in the primary tumor, plasma and serum, and body fluids. As in various cancers, their role in the diagnosis, prognosis, and treatment of patients with malignant pleural mesothelioma (MPM) may be important. Aims: To analyze the predictive value of miR-16-5p, miR-29c-3p, miR-31-5p, miR-125a-5p, miR-320a, miR-484 and miR-532-5p expressions for diagnosis, prognosis and response to treatment in patients with MPM. Study Design: Prospective case-control study. Methods: In the first phase of the study, blood samples were collected from 101 MPM patients before chemotherapy and from 24 healthy donors (HDs). In the second phase, the blood samples were collected from 74 MPM patients who had received chemotherapy when the best overall response and disease recurrence were determined. A quantitative real-time polymerase chain reaction was undertaken to detect the miRNA expression levels. The miRNA expression profiles of MPM patients were compared with those of HDs. The associations between the expression levels of miRNAs and prognosis and response to treatment were then evaluated. Results: All miRNAs, except miR-31-5p, were expressed differently in MPM relative to that in HDs. The expression level of miR-16-5p decreased when compared with that of HDs, and the expression levels of miR-29c-3p, miR-125a-5p, miR-320a, miR-484, and miR-532-5p increased when compared with that of HDs. The sensitivity and specificity values of miR-29c-3p, miR-125a-5p, miR-320a, miR-484, and miR-532-5p for discriminating MPM from HDs were 85.9% and 59.1%, 95.1% and 62.5%, 87.1% and 79.2%, 82.2% and 58.3%, and 69.3% and 82.6%, respectively. After adjusting for the histological subtype, stage, and treatment, the miR-29c-3p, miR-125a-5p, and miR-484 were associated with longer survival. The miRNA expression levels did not change longitudinally for the determination of chemotherapy response and recurrence. Conclusion: miRNAs may be useful in diagnosing patients with MPM and provides helpful information in determining the prognosis of patients.

Medical and Surgical Care of Patients With Mesothelioma and Their Relatives Carrying Germline BAP1 Mutations.

The most common malignancies that develop in carriers of BAP1 germline mutations include diffuse malignant mesothelioma, uveal and cutaneous melanoma, renal cell carcinoma, and less frequently, breast cancer, several types of skin carcinomas, and other tumor types. Mesotheliomas in these patients are significantly less aggressive, and patients require a multidisciplinary approach that involves genetic counseling, medical genetics, pathology, surgical, medical, and radiation oncology expertise. Some BAP1 carriers have asymptomatic mesothelioma that can be followed by close clinical observation without apparent adverse outcomes: they may survive many years without therapy. Others may grow aggressively but very often respond to therapy. Detecting BAP1 germline mutations has, therefore, substantial medical, social, and economic impact. Close monitoring of these patients and their relatives is expected to result in prolonged life expectancy, improved quality of life, and being cost-effective. The co-authors of this paper are those who have published the vast majority of cases of mesothelioma occurring in patients carrying inactivating germline BAP1 mutations and who have studied the families affected by the BAP1 cancer syndrome for many years. This paper reports our experience. It is intended to be a source of information for all physicians who care for patients carrying germline BAP1 mutations. We discuss the clinical presentation, diagnostic and treatment challenges, and our recommendations of how to best care for these patients and their family members, including the potential economic and psychosocial impact.

What has changed in malignant mesothelioma between 1990 and 2019? A time- series analyses in Turkey.

OBJECTIVES: To investigate the changes in epidemiological and survival characteristics of malignant mesothelioma (MM) cases diagnosed in a 30-year period between 1990 and 2019. METHODS: Data were analyzed considering three time periods (1990-1999, 2000-2009, 2010-2019) when treatment practices changed. The Join point Regression Program was used to analyze the change in clinical and epidemiological characteristics of the cases. Kaplan-Meier analysis was used to calculate the overall survival of the patients. Cox regression analysis was used to determine the effect of variables on survival. RESULTS: The study group consisted of 928 MM patients. During the study period, the mean age of the patients and the percentage of epithelioid subtype increased, while the percentage of female and histopathologically unidentified cases decreased. The median survival (95%CI) of patients according to the study periods was 9.0 (7.2-10.9), 9.0 (7.6-10.4) and 12.0 (10.5-13.5) months, respectively. A significant increase in overall survival was observed in the time trend (p = 0.013). There was no significant change in overall survival in patients receiving best supportive care over the 30-year period (p = 0.060), but an improvement of 1.4 (95%CI 0.2 to 2.7) months (p = 0.027) was observed in patient receiving chemotherapy. An improvement in overall survival of 4.8 (1.2 to 8.4) months was also observed in patients receiving multimodality treatment during 2000-2019 (p = 0.014). MM patients who were younger, female, diagnosed after 2000, epithelioid subtype, early stage, and received chemotherapy or multimodal treatment had longer survival. CONCLUSIONS: It was found that histopathological diagnosis and treatment success in MM have improved over the years.

Evaluation of the contribution of fine-needle non-aspiration cytology to diagnosis in cases with pulmonary malignant lesions.

BACKGROUND: Fine-needle non-aspiration cytology (FNNAC) is an easy-to-apply, minimally invasive diagnostic method that contributes to the diagnosis and staging of lung cancer. FNNAC can be performed from peripheral lymph nodes as well as in peripheral lung lesions. This study aimed to evaluate the contribution of FNNAC performed from peripheral lesions or lymph nodes to diagnosis in patients with pulmonary malignant lesions. METHODS: FNNAC was applied from a peripherally located mass in the lung, chest wall lesion, or peripheral lymph node using a needle without an injector or active suction. The collected material was evaluated using the cytoblock method. The FNNAC accuracy was obtained by dividing the true positivity value by a number of needle biopsies performed. The 95% confidence interval of the obtained rate was also calculated. RESULTS: The mean age of 56 patients, two female (3.6%) and 54 male (96.4%), was 63.9 ± 9.1 (38-80) years. FNNAC was performed from the peripheral lymph node in 48 patients, the peripheral pulmonary lesion in four, and the accompanying chest wall lesion in four. While true positivity was present in 42 patients, two patients had true negativity, and 12 had false negativity. In five of the 12 cases reported as false negative, the collected material was evaluated as insufficient, while the malignant diagnoses of the remaining seven cases were confirmed by other diagnostic methods. The diagnostic success of FNNAC was determined as 78.57% (95% CI: 65.56-88.41). FNNAC was more successful in diagnosis when performed from the peripheral lymph node compared to the peripheral pulmonary lesion (p=0.033).

Mesothelioma in immigrants from Turkey: Genes have a minor role.

OBJECTIVE: To examine the incidence and epidemiology of malignant mesothelioma in immigrants from Karain where there is an extraordinarily high incidence of mesothelioma, Cappadocia, Turkey, to Stockholm, Sweden, and their children over 20 years of age born in Stockholm, i.e. two genetically similar populations with and without erionite exposure. METHODS: This survey was conducted as a retrospective cohort study. Standardized average annual mesothelioma incidence rates (AAMIRs) and mesothelioma standardized incidence ratio (mSIR) were calculated. Cox regression analysis was used to determine the importance of different factors related to mesothelioma risk. RESULTS: The cohort consisted of 337 people, 203 of whom were born and/or lived in Karain before immigrating to Sweden (erionite-exposed), and 134 who were born in Stockholm (erionite-unexposed). There were 69 deaths, 42 (61%) due to mesothelioma, and two patients with the disease who were still alive. Of these 44 patients, 22 were men. All mesothelioma patients were in the erionite-exposed group. In the age group 30-49 years, mesothelioma developed in 11 of 38 (29%) with erionite exposure, while there were no cases among 86 persons in the non-exposed group. For men, the AAMIR was 253.9 per 100,000 persons in the whole cohort, and for women, it was 350.9. The mSIR was 71.9 for men and 393.1 for women. Exposure to erionite exceeding 20 years and age over 40 years were associated with increased mesothelioma risk. CONCLUSION: Exposure to erionite is the leading cause of mesothelioma in Karain villagers, and genetic factors are probably of minor importance.

Liquid Biopsies from Pleural Effusions and Plasma from Patients with Malignant Pleural Mesothelioma: A Feasibility Study.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a fatal tumor with a poor prognosis. The recent developments of liquid biopsies could provide novel diagnostic and prognostic tools in oncology. However, there is limited information about the feasibility of this technique for MPMs. Here, we investigate whether cancer-specific DNA sequences can be detected in pleural fluids and plasma of MPM patients as free circulating tumor DNA (ctDNA). METHODS: We performed whole-exome sequencing on 14 tumor biopsies from 14 patients, and we analyzed 20 patient-specific somatic mutations with digital droplet PCR (ddPCR) in pleural fluids and plasma, using them as cancer-specific tumor biomarkers. RESULTS: Most of the selected mutations could be detected in pleural fluids (94%) and, noteworthy, in plasma (83%) with the use of ddPCR. Pleural fluids showed similar levels of somatically mutated ctDNA (median = 12.75%, average = 16.3%, standard deviation = 12.3) as those detected in solid biopsies (median = 21.95%; average = 22.21%; standard deviation = 9.57), and their paired difference was weakly statistically significant (p = 0.048). On the other hand, the paired difference between solid biopsies and ctDNA from plasma (median = 0.29%, average = 0.89%, standard deviation = 1.40) was highly statistically significant (p = 2.5 × 10-7), corresponding to the important drop of circulating somatically mutated DNA in the bloodstream. However, despite the tiny amount of ctDNA in plasma, varying from 5.57% down to 0.14%, the mutations were detectable at rates similar to those possible for other tumors. CONCLUSIONS: We found robust evidence that mutated DNA is spilled from MPMs, mostly into pleural fluids, proving the concept that liquid biopsies are feasible for MPM patients.

Prediction of Radiation Pneumonitis With Machine Learning in Stage III Lung Cancer: A Pilot Study.

BACKGROUND: Radiation pneumonitis (RP) is a dose-limiting toxicity in lung cancer radiotherapy (RT). As risk factors in the development of RP, patient and tumor characteristics, dosimetric parameters, and treatment features are intertwined, and it is not always possible to associate RP with a single parameter. This study aimed to determine the algorithm that most accurately predicted RP development with machine learning. METHODS: Of the 197 cases diagnosed with stage III lung cancer and underwent RT and chemotherapy between 2014 and 2020, 193 were evaluated. The CTCAE 5.0 grading system was used for the RP evaluation. Synthetic minority oversampling technique was used to create a balanced data set. Logistic regression, artificial neural networks, eXtreme Gradient Boosting (XGB), Support Vector Machines, Random Forest, Gaussian Naive Bayes and Light Gradient Boosting Machine algorithms were used. After the correlation analysis, a permutation-based method was utilized for as a variable selection. RESULTS: RP was seen in 51 of the 193 cases. Parameters affecting RP were determined as, total(t)V5, ipsilateral lung Dmax, contralateral lung Dmax, total lung Dmax, gross tumor volume, number of chemotherapy cycles before RT, tumor size, lymph node localization and asbestos exposure. LGBM was found to be the algorithm that best predicted RP at 85% accuracy (confidence interval: 0.73-0.96), 97% sensitivity, and 50% specificity. CONCLUSION: When the clinical and dosimetric parameters were evaluated together, the LGBM algorithm had the highest accuracy in predicting RP. However, in order to use this algorithm in clinical practice, it is necessary to increase data diversity and the number of patients by sharing data between centers.

The role of volumetric method in the assessment of chemotherapy response and predicting survival in malignant pleural mesothelioma.

BACKGROUND: Malignant pleural mesothelioma (MPM) is a pleural tumor with high mortality rate and short-term survival expectancy after diagnosis. Assessment of the response to chemotherapy, which is the first choice in treatment of MPM, is important for the transition to alternative chemotherapy protocols and immunotherapy. There is no clarity in the response to chemotherapy treatment. OBJECTIVE: Our study aims to compare the assessment of chemotherapy response using the Modified Response Evaluation Criteria in Solid Tumors (mRECIST) criteria and volumetric measurements and to correlate with median survival. MATERIALS AND METHODS: Thirty-two patients (16 females and 16 males) were included in the study, and their ages ranged from 28 to 78 years. Chemotherapy response was determined by both mRECIST and volumetric approach. Tumor volume was measured by linear interpolation and semi-automatic segmentation. Log-rank multiple cutoff analysis was used to determine appropriate cutoff values of volumetric response criteria. RESULTS: According to both mRECIST and volumetric approach, median survival times in partial response, stable disease, and progressive disease groups were 24, 15, and 9 months, respectively. The survival times of the three groups were different (logrank: 17.76; P < 0.001) by mRECIST. The survival of the progressive disease group was shorter than that of the other groups (logrank: 18.91; P < 0.001) by volumetric approach. CONCLUSIONS: In the assessment of chemotherapy response, even though classifications obtained according to the mRECIST criteria and volumetric measurements are statistically compatible, we think that the measurement of the volumetric values will increase the standardization. In our study, threshold values for volumetric measurements were determined; however, these values should be supported by large-scale multicenter studies.

Syndecan-1 Overexpressing Mesothelioma Cells Inhibit Proliferation, Wound Healing, and Tube Formation of Endothelial Cells.

Malignant mesothelioma (MM) is an aggressive tumor of the serosal cavities. Angiogenesis is important for mesothelioma progression, but so far, anti-angiogenic agents have not improved patient survival. Our hypothesis is that better understanding of the regulation of angiogenesis in this tumor would largely improve the success of such a therapy. Syndecan-1 (SDC-1) is a transmembrane heparan sulfate proteoglycan that acts as a co-receptor in various cellular processes including angiogenesis. In MM, the expression of SDC-1 is generally low but when present, SDC-1 associates to epithelioid differentiation, inhibition of tumor cell migration and favorable prognosis, meanwhile SDC-1 decrease deteriorates the prognosis. In the present study, we studied the effect of SDC-1 overexpression and silencing on MM cells ability to secrete angiogenic factors and monitored the downstream effect of SDC-1 modulation on endothelial cells proliferation, wound healing, and tube formation. This was done by adding conditioned medium from SDC-1 transfected and SDC-1 silenced mesothelioma cells to endothelial cells. Moreover, we investigated the interplay and molecular functional changes in angiogenesis in a co-culture system and characterized the soluble angiogenesis-related factors secreted to the conditioned media. We demonstrated that SDC-1 over-expression inhibited the proliferation, wound healing, and tube formation of endothelial cells. This effect was mediated by a multitude of angiogenic factors comprising angiopoietin-1 (Fold change ± SD: 0.65 ± 0.07), FGF-4 (1.45 ± 0.04), HGF (1.33 ± 0.07), NRG1-ß1 (1.35 ± 0.08), TSP-1 (0.8 ± 0.02), TIMP-1 (0.89 ± 0.01) and TGF-ß1 (1.35 ± 0.01). SDC-1 silencing increased IL8 (1.33 ± 0.06), promoted wound closure, but did not influence the tube formation of endothelial cells. Pleural effusions from mesothelioma patients showed that Vascular Endothelial Growth Factor (VEGF) levels correlate to soluble SDC-1 levels and have prognostic value. In conclusion, SDC-1 over-expression affects the angiogenic factor secretion of mesothelioma cells and thereby inhibits endothelial cells proliferation, tube formation, and wound healing. VEGF could be used in prognostic evaluation of mesothelioma patients together with SDC-1.