Prognostic Score of Long-Term Survival After Surgery for Malignant Pleural Mesothelioma: A Multicenter Analysis

Long-Term Survival Analysis of Pleural Mesothelioma Patients Undergoing Surgery: Brief Report From a Tertiary Referral Centre

OBJECTIVES

to date, no consensus has been reached on the surgical gold-standard in pleural mesothelioma (PM). We retrospectively reviewed our experience as a tertiary referral centre, to compare short- and long-term survival of PM patients undergoing different types of surgery.

METHODS

in retrospective, observational, single-centre study, we analysed all the patients histologically diagnosed with PM undergoing surgical procedures with palliative or curative intent at IRCCS Istituto Nazionale dei Tumori of Milan, Italy, from January 2003 to December 2020. The primary study endpoint was 10-year overall survival (OS) in three different types of resections: extra-pleural-pneumonectomy (EPP), pleurectomy/decortication (P/D), partial-pleurectomy/pleural-biopsy (PP/B). Secondary endpoints were postoperative hospital stay and postoperative 30-day and 90-day mortality rates. The survival function was estimated using Kaplan-Meier, and the Log-rank test was used for testing differences. Univariable and Multivariable Cox regression models were implemented to estimate Hazard Ratio (HR) for all variables of interest.

RESULTS

243 consecutive patients were enrolled, EPP was performed in 49 (20.2%), P/D in 58 (23.8%), PP/B in 136 (56.0%) patients. The median follow-up time was 19.8 months. 10-year OS was significantly better for P/D group (16%, Log-Rank test p<0.0001) compared to PP/B (1.8%) and EPP (0%). No statistically significant differences were found among the 3 surgical groups in 30- and 90-day mortality rates. At multivariable analysis, gender (male, HR=1.58), type of resection (P/D, HR=0.55) and surgery date (recent years, HR=0.61) were found to be independent prognostic factors for OS.

CONCLUSIONS

in PM, lung-sparing curative approach (e.g. P/D) should be preferred in highly selected patients and in highly experienced centres, whenever appropriate. Anyway, when P/D is not indicated, adopting palliative/conservative management (e.g. PP/B) could ensure comparable results as extremely aggressive surgeries (e.g. EPP). The aim of surgery in PM should not be reaching complete resection, but rather accomplishing significant resection allowing to complete the multimodality treatment in highly selected patients in experienced centers.

Reliability of assessing morphologic features with prognostic significance in cytology specimens of epithelioid diffuse pleural mesothelioma and implications for cytopathology reporting

BACKGROUND

The World Health Organization incorporates morphologic features with prognostic significance in the 2021 classification of epithelioid diffuse pleural mesothelioma (E-DPM). Although cytology specimens are often the first and occasionally the only specimen available for patients with DPM, these features have not yet been investigated in cytology.

METHODS

Nuclear atypia, pleomorphic features, necrosis, and architectural patterns were retrospectively assessed in 35 paired cytology and concurrent/consecutive surgical pathology specimens of E-DPM. Agreement between pairs was determined via unweighted κ scores. Discordant cases were re-reviewed to determine the reasons for disagreement.

RESULTS

Interpretation of nuclear atypia in cytology was concordant with histology in all cases (κ = 1.000; p < .001). The presence of pleomorphic features and necrosis was concordant in 97.1% (κ = 0.842; p < .001) and 85.7% (κ = 0.481; p = .001) of paired cases, respectively. Assessment of architectural patterns in cytology showed only slight agreement with histology (κ = 0.127; p = .037). In cytology cases (n = 23) with cell block material available, assessment of nuclear atypia and the presence of pleomorphic features showed perfect agreement (κ = 1.000; p < .001, each), the presence of necrosis showed moderate agreement (κ = 0.465; p = .008), and assessment of architectural patterns showed slight agreement (κ = 0.162; p = .15) in paired specimens. Most disagreements were due to sampling differences between cytology and histology specimens.

CONCLUSIONS

Although complete nuclear grading of E-DPM is not possible given the unreliability of mitotic counts in cytology, assessment of nuclear atypia in cytology specimens is shown to be reliable. Identification of pleomorphic features and necrosis is also reliable despite occasional sampling issues. Assessment of architectural patterns is more limited in cytology.

Predicting survival for patients with mesothelioma: development of the PLACE prognostic model

INTRODUCTION

The overall survival of patients with mesothelioma is poor and heterogeneous. At present, the prediction model for Chinese patients needs to be improved. We sought to investigate predictors of survival in malignant pleural mesothelioma and develop prognostic prediction models.

METHODS

This Two-center retrospective cohort study recruited patients with pathologically diagnosed mesothelioma at Beijing Chao-Yang Hospital and Beijing Tong-Ren Hospital. We developed a new prognostic prediction model based on COX multivariable analysis using data from patients who were recruited from June 1, 2010 to July 1, 2021 in Beijing Chao-Yang Hospital (n = 95, development cohort) and validated this model using data from patients recruited from July 18, 2014 to May 9, 2022 in Beijing Tong-Ren Hospital (n = 23, validation cohort). Receiver operating characteristic analysis was used to estimate model accuracy.

RESULTS

The parameters in this new model included PLT > 289.5(10^9/L) (1 point), Lymphocyte > 1.785(10^9/L) (-1point), Age > 73 years old (1 point), Calcium > 2.145(mmol/L) (-1point), Eastern Cooperative Oncology Group performance status (ECOG PS) > 2 (2 points). When the sum of scores < 0, it is recognized as a low-risk group; when the score is 0 ~ 3, it is recognized as a high-risk group. The survival rate of patients in the high-risk group was significantly lower than that in the low-risk group (hazard ratio [HR], 3.878; 95% confidence interval [CI], 2.226-6.755; P < 0.001). The validation group had similar results (HR,3.574; 95%CI,1.064-12.001; P = 0.039). Furthermore, the areas under the curve 6 months after diagnosis in the two cohorts were 0.900 (95% CI: 0.839-0.962) and 0.761 (95% CI: 0.568-0.954) for development and validation cohorts, respectively.

CONCLUSION

We developed a simple, clinically relevant prognostic prediction model for PLACE by evaluating five variables routinely tested at the time of diagnosis. The predictive model can differentiate patients of Chinese ethnicity into different risk groups and further guide prognosis.

Contemporary issues in the surgical management of pleural mesothelioma

The surgical management of pleural mesothelioma (PM) can be divided into diagnostic, staging, palliation, and cytoreductive surgery. In the cytoreductive surgical setting, the combination of different treatment modalities has led to better outcomes than surgery alone. The scarcity of high-quality studies has led to heterogeneity in management of PM across the mesothelioma treatment centers. Here, we review the literature regarding the most important open questions and ongoing clinical trials.

Survival analysis and development of a prognostic nomogram for patients with malignant mesothelioma in different anatomic sites

Background

Malignant mesothelioma (MMe) is a rare and fatal cancer with a poor prognosis. Our study aimed to compare the overall survival (OS) of MMe patients across various sites and develop a prognostic model to provide a foundation for individualized management of MMe patients.

Methods

From the Surveillance, Epidemiology, and End Results (SEER) database, 1,772 individuals with malignant mesothelioma (MMe) were identified. The X-tile software was used to identify the optimal cut-off point for continuous variables. The Kaplan–Meier method was employed to compare the survival of MMe across different sites. The Cox proportional hazards model was applied to identify the independent risk factors of overall survival (OS) and a nomogram was constructed.

Results

In the survival analysis, MMe originating from the reproductive organs and hollow organs showed a relatively better prognosis than those originating from soft tissue, solid organs, and pleura. Age, gender, location, histological type, grade of differentiation, extent of disease, lymph node status, lymph node ratio (LNR), and chemotherapy were all found to be independent risk variables for the prognosis of MMe patients (P&lt;0.05) in a multivariate Cox analysis and were included in the construction of nomogram. In the training and testing sets, the C-index of the nomogram was 0.701 and 0.665, respectively, and the area under the ROC curve (AUROC) of the 1-, 3-, and 5-year overall survival rate was 0.749, 0.797, 0.833 and 0.730, 0.800, 0.832, respectively. The calibration curve shows that the nomogram is well-calibrated.

Conclusions

This is the first research to examine the prognosis of MMe patients based on the location. However, previous studies often focused on malignant pleural mesothelioma or malignant peritoneal mesothelioma with high incidence. Furthermore, a nomograph with good prediction efficiency was established according to the variables that influence patient survival outcomes, which provides us with a reference for clinical decision-making.

Preoperative Identification of Benefit from Surgery for Malignant Pleural Mesothelioma

In the absence of standardized treatment algorithms for patients with malignant pleural mesothelioma, one of the main difficulties remains patient allocation to therapies with potential benefit. This article discusses clinical, radiologic, pathologic, and molecular prognostic factors as well as genetic background leading to preoperative identification of benefit from surgery, which have been investigated over the past years to simplify and at the same time specify patient selection for surgical treatment.

Clinical Features in Patients With Malignant Pleural Mesothelioma With 5-Year Survival and Evaluation of Original Diagnoses

INTRODUCTION

Malignant pleural mesothelioma (MPM) is a fatal malignancy strongly associated with previous asbestos exposure. Overall survival remains dismal, partly owing to poor response to available treatment. The aims of this study were to evaluate diagnostic accuracy in a group of patients with MPM with an unusually long survival time and to assess the factors related to this prolonged survival.

MATERIALS AND METHODS

Forty-three patients with overall survival exceeding 5 years were accepted to the long-term survivor (LTS) group, and these patients were compared with 84 patients with epithelial MPM. Data were collected from various national registries and electronic medical records. In addition, all available histopathologic diagnostic samples and computed tomography studies were re-evaluated by experienced specialists.

RESULTS

Our study showed a good diagnostic accuracy, with only 1 (0.5%) patient having an incorrect MPM diagnosis. Two (0.9%) localized malignant mesotheliomas and 2 (0.9%) well-differentiated papillary mesotheliomas were also found. LTS patients were younger, more frequently female, had a better performance status at time of diagnosis, and had less evidence of prior asbestos exposure. In multivariate analysis, we showed tumor size, Eastern Cooperative Oncology Group performance status, and first-line treatment (both surgery and chemotherapy) to be associated with survival time.

CONCLUSION

We confirmed the diagnosis of MPM in an overwhelming majority of patients in the LTS group. An epithelial subtype of MPM behaving clinically more indolently seems to exist, but further tumor and genetic characterization is needed. The prolonged survival time is most likely explained by a combination of tumor-, patient-, and treatment-related factors.

Histopathological features of epithelioid malignant pleural mesotheliomas in patients with extended survival

Diffuse malignant mesothelioma (DMM) of the pleura is a rare and aggressive disease, wherein the long-term survival (LTS) rate is low. The epithelioid subtype is the most prevalent form of DMM with the best prognosis. To study prognostic histopathologic factors associated with extended survival in epithelioid DMM, we examined 43 tumors from patients with survival more than five years (LTSs) and compared the findings with 84 tumors from a reference group (RG) with average survival. We analyzed the tumors considering previously published histopathological prognostic features and attempted to identify additional morphological features predictive of extended survival. Most of the LTS tumors presented with nuclear grade I (n = 34, 90%) and a tubulopapillary growth pattern (n = 30, 70%). One LTS tumor had necrosis. In contrast, nuclear grade II (n = 49, 61%) and solid growth pattern (n = 59, 70%) were more frequent in the RG, and necrosis was present in 16 (19%) tumors. We also evaluated the association of asbestos lung tissue fiber burden quantified from autopsy samples with histopathological features and found that elevated asbestos fiber was associated with higher nuclear grade (P < 0.001) and the presence of necrosis (P = 0.021). In univariate survival analysis, we identified the following three novel morphological features associated with survival: exophytic polypoid growth pattern, tumor density, and single mesothelium layered tubular structures. After adjustments, low nuclear grade (P < 0.001) and presence of exophytic polypoid growth (P = 0.024) were associated with prolonged survival. These results may aid in estimating DMM prognosis.

CDKN2A copy number and p16 expression in malignant pleural mesothelioma in relation to asbestos exposure

Background

Deletion of the CDKN2A locus is centrally involved in the development of several malignancies. In malignant pleural mesothelioma (MPM), it is one of the most frequently reported genomic alteration. MPM is strongly associated with a patients’ asbestos exposure. However, the status of CDKN2A and the expression of the corresponding protein, p16, in relation to MPM patient’s asbestos exposure is poorly known. Copy number alterations in 2p16, 9q33.1 and 19p13 have earlier been shown to accumulate in lung cancer in relation to asbestos exposure but their status in MPM is unclear.

Methods

We studied DNA copy numbers for CDKN2A using fluorescence in situ hybridization (FISH) and p16 expression by immunohistochemistry (IHC) in 92 MPM patients, 75 of which with known asbestos exposure status. We also studied, in MPM, copy number alterations in 2p16, 9q33.1 and 19p13 by FISH.

Results

We were unable to detect an association between p16 expression and pulmonary asbestos fiber count in MPM tumor cells. However, significantly more MPM patients with high pulmonary asbestos fiber count (> 1 million fibers per gram [f/g]) had stromal p16 immunoreactivity than MPM of patients with low exposure (≤ 0.5 million f/g) (51.4% vs 16.7%; p = 0.035, Chi-Square). We found that an abnormal copy number of CDKN2A in MPM tumor cells associated with a high pulmonary asbestos fiber count (p = 0.044, Fisher’s Exact test, two-tailed). In contrast to our earlier findings in asbestos associated lung cancer, DNA copy number changes in 2p16, 9q33 and 19p13 were not frequent in MPM although single cases with variable copy numbers on those regions were seen.

Conclusions

We found two instances where the gene locus CDKN2A or its corresponding protein expression, is associated with high asbestos exposure levels. This suggests that there may be biological differences between the mesotheliomas with high pulmonary asbestos fiber count and those with low fiber count.

Electronic supplementary material

The online version of this article (10.1186/s12885-019-5652-y) contains supplementary material, which is available to authorized users.

Survival analysis via nomogram of surgical patients with malignant pleural mesothelioma in the Surveillance, Epidemiology, and End Results database

Background

Malignant pleural mesothelioma (MPM) is a rare but aggressive tumor that originates from the pleura and has a poor prognosis. Eligible patients can benefit from surgery, but their survival is affected by many factors. Therefore, we created a graphic model that could predict the prognosis of surgically treated patients.

Methods

We retrospectively analyzed data from the Surveillance, Epidemiology, and End Results database from 2004 to 2014 to identify the key factors affecting the prognosis of surgically treated MPM patients. On this basis we built a nomogram to predict survival. We then evaluated the performance of the nomogram in a validation cohort.

Results

In a training cohort of 828 cases, independent prognostic factors, including age, gender, histological type, differentiation, N stage, chemotherapy, type of surgery, and lymph node dissection, were identified. We then developed a nomogram to evaluate individual patient survival. In Kaplan–Meier analysis, a higher score in the nomogram was associated with a worse prognosis. We also used a validation cohort consisting of 312 patients to evaluate the performance of the nomogram, which was well calibrated and had good discrimination ability, with concordance indices of 0.715 and 0.656 for the training and validation cohorts, respectively.

Conclusion

This study has improved our understanding of resected MPM and shown that key factors, including age and histological type, are associated with overall survival. The nomogram is a reliable tool that can help clinicians turn individualized prediction into reality and maximize patient benefit by identifying the most beneficial treatment approach.

Glycodelin is a potential novel follow-up biomarker for malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a rare and aggressive tumor with a short survival time arising from the mesothelial cells of the pleura. Soluble mesothelin-related peptide (SMRP), osteopontin or EFEMP1 (Fibulin-3) are well described biomarkers for malignant mesothelioma with moderate sensitivity and specificity. In this study, we characterized the expression of glycodelin, a marker for risk pregnancy, in MPM by RNA and protein analyses and investigated its potential as a MPM biomarker. We were able to detect glycodelin in the serum of MPM patients. Compared to benign lung diseases, the serum levels were significant increased. Patients with high glycodelin serum levels revealed a worse overall survival. The glycodelin serum levels correlated with the tumor response to treatment. A comparison of SMRP and glycodelin serum measurement in a large patient cohort demonstrated that the detection of both soluble factors can increase the reliable diagnostic of MPM. Glycodelin was highly expressed in MPM tumors. Analyses of a tissue micro array indicated that the immunomodulatory form glycodelin A was expressed in MPM and correlated with the survival of the patients. Altogether, glycodelin seems to be a new potential biomarker for the aggressive malignant pleural mesothelioma.

Minor regression and long-time survival (56 months) in a patient with malignant pleural mesothelioma under Viscum album and Helleborus niger extracts-a case report

Malignant pleural mesothelioma (MPM) is a rare cancer with a dismal prognosis. Viscum album extracts (VAE) have strong immune stimulatory properties, cytotoxic effects, can downregulate cancer genes and inhibit angiogenesis. VAE are often used as an adjunct treatment in cancer patients but have rarely been investigated in MPM. Helleborus niger extracts (HNE) have been used in anticancer therapy since antiquity, and also show tumor specific cytotoxic effects. We present a case of a 64-year old woman with epithelioid MPM of the right chest with node involvement (T2N1M0, stage III). Deciding against the recommended radio-chemotherapy, surgery and pleurodesis, she opted for an integrative treatment approach and was treated with VAE and HNE. After 6 weeks' treatment, the pleural and nodal MPM manifestations were reduced by about 15%. Subsequent tumor growth was slow, and the patient remained in good health, enabling her to remain physically active until shortly before her death 56 months after the initial diagnosis. This is a rare case of an MPM patient not receiving any standard anticancer treatment; it still shows an extraordinary long survival and good performance status. We presume that VAE and HNE might had an impact on this clinically relevant outcome and therefore should be further investigated in MPM.

The revised staging system for malignant pleural mesothelioma based on surveillance, epidemiology, and end results database

BACKGROUND

Several staging systems for MPM have been introduced. However, none of them provide perfect survival stratification among heterogeneous patients. The aim of this population-based cohort study was to propose adjustments to current staging system for malignant pleural mesothelioma (MPM).

METHODS

We retrieved MPM data from Surveillance, Epidemiology, and End Results database (1973-2014). Kaplan-Meier method was derived to examine the prognostic effects of tumor, lymph node, metastasis and histology features. Proportional hazards models guided adjustments to stage groupings. The accuracy of staging systems at predicting survival was evaluated by concordance index and bootstrap resampling.

RESULTS

A total of 1110 MPM cases were extracted from SEER. T stage failed to demonstrate survival difference between adjacent categories with the exception of T3 versus T4 (P < 0.001). Patients in M0 had better prognosis than those in M1 (P < 0.001). Exploratory analyses suggested important survival difference for single-versus multiple-site M1 cases (P < 0.001), but not for different metastatic sites (P = 0.286). Histology subtype was a significant prognostic indicator (P < 0.001). Regrouping of TNM and histology combinations resulted in the best concordance index (0.683), compared with UICC 2010 (0.578) and IASLC 2016 (0.585) staging systems. The revised staging system also improved patients distribution (IA:33.8%, IB:17.0%, II: 20.7%, IIIA:10.6%, IIIB: 6.8%, IV:11.1%). Log-rank analyses and calibration plots both demonstrated the new stage achieved optimal survival prediction and discrimination.

CONCLUSION

The revised staging system improved patients distribution and survival stratification for MPM.

Reproducibility for histologic parameters in peritoneal mesothelioma

Histologic subtype is recognized as a prognostic factor in malignant pleural mesothelioma. Specifically, epithelial morphology is associated with a better prognosis than other subtypes, and the same association is observed in peritoneal malignant mesothelioma. Recently, prognostic differences based on morphologic subtypes of epithelial peritoneal malignant mesothelioma were reported. Herein, we report the interobserver variability across four pathologists at three institutions. The authors independently reviewed 67 cases of malignant peritoneal epithelioid mesotheliomas and subclassified them according to their epithelial subtype: papillary, tubulopapillary, trabecular, micropapillary, solid and/or pleomorphic. The cases were also evaluated by each author for several other histopathologic parameters including depth of invasion, nuclear grade, lymphocytic host response, mitotic count/index, presence of lymphovascular invasion, and stromal desmoplasia. The interobserver agreement for histopathologic parameters was highest for mitotic rate (κ=0.36) and primary epithelial subtype (κ=0.32). The interobserver variability for solid subtype pattern was moderate (κ=0.49). We found that the interobserver variability for most histopathologic parameters is poor.

Extrapleural pneumonectomy (EPP) vs. pleurectomy decortication (P/D)

Surgical techniques for treatment of malignant pleural mesothelioma (MPM) have improved over the decades. The main surgical principle was accepted as macroscopic complete resection. This principle was achieved with extrapleural pneumonectomy (EPP) and extended pleurectomy/decortication (P/D). Mortality and morbidity are higher following EPP with supraventricular arrhythmias, pulmonary embolism, bronchopleural fistula and pulmonary failure being the most common, while prolonged air leak is frequent following P/D. Completion of multimodality treatment was also shown to be a prognostic factor. Many different neoadjuvant and adjuvant protocols were applied with limited effect on prognosis. While locoregional recurrence is more common following P/D, EPP patients typically recur in contralateral hemithorax and abdomen. Hemithoracic radiation following EPP was the only effective technique shown to decrease locoregional recurrence. However, neither surgical technique (EPP vs. P/D), nor types of multimodality treatment protocols were found to be prognostic in MPM. Epithelioid histology, metastasis to extrapleural lymph nodes and completion of multimodality treatment were prognostic in most of the series. In conclusion, based on the current evidence, the choice of a less morbid and mortal procedure (P/D) seems to be the logical choice in the treatment of MPM.

The role of thoracic surgery in the management of mesothelioma: an expert opinion on the limited evidence

Surgery has a key role at different points in the management of Malignant Pleural Mesothelioma. Diagnosis with video assisted thoracoscopy offers excellent sensitivity and specificity and a direct view of the pleural cavity to verify the extent of the tumor. Nodal involvement can be assessed by mediastinoscopy and either talc pleurodesis or partial pleurectomy can be used for symptom control in advanced stage disease. Extra Pleural Pneumonectomy (EPP) and Extended Pleurectomy Decortication (EPD) are used to prolong survival although the benefit of radical surgery has not has been fully clarified; EPP failed to show its benefit in the MARS trial and EPD is currently under investigation in the MARS2 trial. More randomized prospective trial data are needed to fully understand the role of radical surgery in the treatment of pleural mesothelioma.

Mithramycin Depletes Specificity Protein 1 and Activates p53 to Mediate Senescence and Apoptosis of Malignant Pleural Mesothelioma Cells

PURPOSE

Specificity protein 1 (SP1) is an oncogenic transcription factor overexpressed in various human malignancies. This study sought to examine SP1 expression in malignant pleural mesotheliomas (MPM) and ascertain the potential efficacy of targeting SP1 in these neoplasms.

EXPERIMENTAL DESIGN

qRT-PCR, immunoblotting, and immunohistochemical techniques were used to evaluate SP1 expression in cultured MPM cells and MPM specimens and normal mesothelial cells/pleura. MTS, chemotaxis, soft agar, β-galactosidase, and Apo-BrdUrd techniques were used to assess proliferation, migration, clonogenicity, senescence, and apoptosis in MPM cells following SP1 knockdown, p53 overexpression, or mithramycin treatment. Murine subcutaneous and intraperitoneal xenograft models were used to examine effects of mithramycin on MPM growth in vivo. Microarray, qRT-PCR, immunoblotting, and chromatin immunoprecipitation techniques were used to examine gene expression profiles mediated by mithramycin and combined SP1 knockdown/p53 overexpression and correlate these changes with SP1 and p53 levels within target gene promoters.

RESULTS

MPM cells and tumors exhibited higher SP1 mRNA and protein levels relative to control cells/tissues. SP1 knockdown significantly inhibited proliferation, migration, and clonogenicity of MPM cells. Mithramycin depleted SP1 and activated p53, dramatically inhibiting proliferation and clonogenicity of MPM cells. Intraperitoneal mithramycin significantly inhibited growth of subcutaneous MPM xenografts and completely eradicated mesothelioma carcinomatosis in 75% of mice. Mithramycin modulated genes mediating oncogene signaling, cell-cycle regulation, senescence, and apoptosis in vitro and in vivo. The growth-inhibitory effects of mithramycin in MPM cells were recapitulated by combined SP1 knockdown/p53 overexpression.

CONCLUSIONS

These findings provide preclinical rationale for phase II evaluation of mithramycin in patients with mesothelioma.