Extrapleural pneumonectomy for sarcoma: Outcomes of adult patients at a specialized center.

BACKGROUND: Extrapleural pneumonectomy (EPP) is a complex surgical procedure involving en-bloc resection of the parietal and visceral pleura, lung, pericardium, and ipsilateral diaphragm. Small case series of pleural-based sarcoma of predominantly pediatric patients suggest EPP may be a life-prolonging surgical option. We aimed to describe the characteristics and outcomes of adults who underwent EPP at a specialized sarcoma center. METHODS: Clinicopathologic variables, surgical details, and follow-up information were extracted for patients undergoing EPP for pleural-based sarcoma between August 2017 and December 2020. Primary outcomes were event-free survival (EFS) and overall survival (OS) from the date of EPP. Secondary outcomes were disease-free interval (DFI) prior to EPP, and early and late postoperative complications. RESULTS: Eight patients were identified, seven with soft tissue sarcoma and one with bone sarcoma. Patients had either localized disease with a primary thoracic sarcoma, sarcoma recurrent to the thorax, or de novo metastatic disease. All patients underwent resection of their pleural-based sarcoma by an experienced cardiothoracic surgeon, and some patients had pre or postoperative treatment. The perioperative morbidity was comparable with previously published reports of EPP performed in mesothelioma patients. At median follow-up of 22.5 months, median EFS was 6.0 months and OS was 20.7 months. Six patients (75%) had disease recurrence; five (62.5%) died of progressive disease. Two patients (25%) had not recurred: one died of a radiation-related esophageal rupture, and one was alive with no evidence of disease at 37.0 months. Characteristics of those with the longest EFS included low-grade histology and achieving a metabolic response to preoperative chemotherapy. CONCLUSIONS: In adults with pleural-based sarcoma, EPP is rarely curative but appears to be a feasible salvage procedure when performed at specialized centers. Patient selection is critical with strong consideration given to multimodal therapy to optimize patient outcomes. In the absence of a confirmed response to neoadjuvant treatment, long term survival is poor and EPP should not be recommended.

Mesothelioma of the tunica vaginalis testis.

Mesothelioma of the tunica vaginalis testis (MTVT) is a rare tumour and a cause of hydrocele. This case report concerns a 26-year-old male with hydrocele treated with left hydrocelectomy. Histopathology revealed MTVT, and left radical orchiectomy was performed followed by chemotherapy. Fluorescence in situ hybridization, DNA and RNA next-generation sequencing showed no mesothelioma-associated tumour suppressor gene mutations, but deletion of CDKN2A and a rare TFG-ADGRG7 fusion both reported in pleural mesotheliomas, were detected. Clinicians should consider malignancy in case of discrepancy between symptoms and objective findings in scrotal conditions.

Testicular mesothelioma disguised as hydrocele: a case report.

BACKGROUND: Testicular tumors have many different manifestations. The majority of these cases are presented as an incidental finding during hydrocelectomy. Malignant mesotheliomas are uncommon tumours that can arise from the coelomic epithelium of the pleura, peritoneum, pericardium, and tunica vaginalis. CASE PRESENTATION: We present a 51-year-old South Asian (Indian) male patient with a rare case of mesothelioma, presenting with right hydrocele, to whom a right hydrocelectomy was performed. Any history of trauma or asbestos exposure was not present. Histopathological and immunohistochemistry reports revealed a malignant mesothelioma of tunica vaginalis. There was no invasion of the tumour to the epididymis and spermatic cord. Imaging studies showed no signs of metastasis. 1 month later, a high inguinal orchidectomy was performed. The patient underwent adjuvant chemotherapy thereafter and is still on follow-up. CONCLUSION: Although hydrocele is common, detailed evaluation is mandatory to rule out certain rare tumours-testicular and paratesticular variants.

Mesothelioma of Uncertain Malignant Potential (MUMP) of the Tunica Vaginalis: Proposal for Reclassification as "Complex Mesothelial Tumor of the Tunica Vaginalis".

A well-differentiated papillary mesothelial tumor (WDPMT) and malignant mesothelioma are 2 well-recognized entities arising from the testis tunica vaginalis. Another mesothelial lesion exclusively seen at this site is mesothelioma of uncertain malignant potential (MUMP)-a lesion reminiscent of WDPMT yet demonstrating variable proportions of more complex architectural patterns that could be confused with invasion. MUMP was first described in 2010 with a total of 11 cases reported to date. Herein, we describe 19 additional patients who underwent hydrocelectomy, excision, and/or orchiectomy. Novel morphologic patterns found in addition to the 2010 series include spindle cells, keloidal-type collagen, and multicystic architecture lined by bland mesothelial cells. Clinical follow-up in 9 patients for more than 1 year (1.5 to 22.5 y, median 4.5 y) revealed no evidence of disease recurrence or metastases. Despite greater architectural complexity, MUMP has (1) bland cytology; (2) merging in with WDPMT areas; (3) low mitotic rate and Ki-67 nuclear labeling index; (4) retention of MTAP and BAP1 expression; and (5) benign clinical follow-up. If these cases were malignant mesotheliomas, one would have expected at least some of the patients to demonstrate disease recurrence/progression without adjuvant therapy within the available follow-up time, particularly with limited resection in most patients. Thus, we propose that "mesothelioma of uncertain malignant potential" be renamed as "complex mesothelial tumor of the tunica vaginalis." Using the term "complex" draws a contrast with the simple cuboidal lining and simple papillary architecture seen in WDPMT. Also, labeling the lesion as "tumor" removes the stigmata of "uncertain malignant potential" and "mesothelioma" that are alarming to patients and clinicians, and potentially could unduly lead to more extensive surgery in an attempt at "complete" resection. At the same time, not definitively labeling the lesion as benign allows recommendations for follow-up.

A Rare Presentation of Minimally Invasive Mesothelioma as a Large Tension Pneumothorax.

Development of mesothelioma is associated with asbestos exposure. Common presentations are with pleural-based plaques invading the chest wall and/or pleural effusion on chest imaging. The intent of this case report is to describe a rare presentation of mesothelioma, which presented atypically as a large tension pneumothorax. A 93-year-old male presented with a history of dyspnea that started after a coughing episode. On physical examination he was hemodynamically stable, but was hypoxic requiring 2L of supplemental oxygen. Computed tomography of the chest revealed a large right tension pneumothorax. A chest tube was placed and connected to suction (-20cmH20), but he continued to have an unresolving air leak over the following 2-week period. Upon video-assisted thoracotomy there were no blebs or adhesions seen. Right apical wedge resection and talc pleurodesis were performed. Pathologic examination revealed an atypical mesothelial cell proliferation with minimal, focal invasion into the pulmonary parenchyma. Tumor spread along the visceral pleura was thought to be the underlying cause of the pneumothorax. The surgical margins were uninvolved by the tumor, and the patient was later discharged home in stable condition. This was a rare presentation of what could best be described as minimally invasive mesothelioma arising in a background of probable mesothelioma in situ, which presented atypically as a large tension pneumothorax. This case highlighted the importance of establishing a pathologic diagnosis from pleural effusion cytology and/or pleural biopsy in persons presenting with spontaneous pneumothorax, and the difficulty in confirming a pathologic diagnosis of early mesothelial neoplasia.

Genomic profiling of tissue and blood predicts survival outcomes in patients with resected pleural mesothelioma.

PURPOSE: Pleural mesothelioma (PM) is an aggressive tumor still considered incurable, in part due to the lack of predictive biomarkers. Little is known about the clinical implications of molecular alterations in resectable PM tissues and blood. Here, we characterized genetic alterations to identify prognostic and predictive biomarkers in patients with resected PM. EXPERIMENTAL DESIGN: Targeted next-generation sequencing was performed in retrospective pleural tumor tissue and paired plasma samples from stage IB-IIIB resected PM. Association between prognosis and presence of specific mutations was validated in silico. RESULTS: Thirty PM tissues and paired blood samples from 12 patients were analyzed. High tissue tumor mutational burden (TMB) (>10 mutations/Mb), tissue median minor allele frequency (MAF) (>9 mutations/Mb), and blood TMB (>6 mutations/Mb), tissue KMT2C, PBRM1, PKHD1,EPHB1 and blood LIFR mutations correlated with longer disease-free survival and/or overall survival. High concordance (>80%) between tissue and blood was found for some mutations. CONCLUSIONS: Tissue TMB and MAF, blood TMB, and specific mutations correlated with outcomes in patients with resected PM and should be further studied to validate their role as prognostic biomarkers and potentially predictive factors for combinations with immune-checkpoint inhibitors. This suggest that molecular profiling could identify longer survivors in patients with resected PM.

Clinical outcomes of stereotactic body radiation therapy for malignant pleural mesothelioma.

BACKGROUND: The objective of this study is to determine the outcomes and toxicities of patients with malignant pleural mesothelioma (MPM) treated with stereotactic body radiotherapy (SBRT). MATERIALS AND METHODS: Data were extracted from an institutional tumor registry for patients diagnosed with mesothelioma and treated with SBRT. Kaplan-Meier and Cox regression analyses were employed to determine local control (LC) and overall survival (OS). RESULTS: Forty-four patients with 59 total treated tumors from December 2006 to April 2022 were identified. Fifty-one (86.4 %) cases had oligoprogressive disease (five sites or less). The median prescription dose delivered was 3000 cGy in 5 fractions (range: 2700-6000 cGy in 3-8 fractions). Fifty-one (86.4 %) tumors were in the pleura, 4 (6.8 %) spine, 2 (3.4 %) bone, 1 (1.7 %) brain, and 1 (1.7 %) pancreas. The median follow-up from SBRT completion for those alive at last follow-up was 28 months (range: 14-52 months). The most common toxicities were fatigue (50.8 %), nausea (22.0 %), pain flare (15.3 %), esophagitis (6.8 %), dermatitis (6.8 %), and pneumonitis (5.1 %). There were no grade ≥ 3 acute or late toxicities. There were 2 (3.4 %) local failures, one of the pleura and another of the spine. One-year LC was 92.9 % (95 % CI: 74.6-98.2 %) for all lesions and 96.3 % (95 % CI: 76.5-99.5 %) for pleural tumors. One-year LC was 90.9 % (95 % CI: 68.1-97.6 %) for epithelioid tumors and 92.1 % (95 % CI: 72.1-98.0 %) for oligoprogressive tumors. One-year OS from time of SBRT completion was 36.4 % (95 % CI: 22.6-50.3 %). On multivariable analysis, KPS was the lone significant predictor for OS (p = 0.029). CONCLUSIONS: Our single-institutional experience on patients with MPM suggests that SBRT is safe with a low toxicity profile and potentially achieve good local control.

Principles of Surgical Management of Peritoneal Mesothelioma.

Malignant peritoneal mesothelioma (MPeM) is a rare malignancy and represents 5% to 30% of malignant mesothelioma cases. The primary curative therapy for MPeM is radical cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC), with the strongest predictor of long-term survival being complete cytoreduction. There is a paucity of high-quality evidence available to guide management in MPeM; however, NCCN Guidelines for the management of MPeM were updated this year. In well-selected patients, 5-year overall survival exceeds 65%, but achieving optimal results requires careful preoperative evaluation and expert surgical management. Preoperative patient selection includes histology review and staging with cross-sectional imaging. Ideal candidates for curative intent surgery are those with epithelioid MPeM, a low peritoneal cancer index, and a good performance status. Contraindications to curative intent surgery include the sarcomatoid MPeM, distant metastases, extensive nodal metastases, and extensive small bowel serosal or mesentery involvement not amenable to complete cytoreduction. Those with biphasic histology, bicavitary disease, and metastatic lymphadenopathy may be considered for surgery following response to neoadjuvant therapy. CRS involves resection of all peritoneal disease, the extent of which varies case by case. Key aspects involve careful evaluation of all peritoneal surfaces, complete parietal peritonectomy and omentectomy, and evaluating suspicious abdominal lymph node basins. Once maximum cytoreduction is achieved, HIPEC is performed using a platinum-based perfusate. Postoperative protocols are recommended to optimize recovery and mitigate HIPEC-specific complications, namely chemotherapy-mediated nephrotoxicity and bone marrow suppression.

En bloc resection of the recurrent pleural mesothelioma and reconstruction of the chest wall after immunotherapy: A case report.

Malignant pleural mesothelioma (MPM) is associated with previous asbestos exposure, while more clinical insights into this disease have come from other case studies. Maximal cytoreduction is critical in disease control and might help to improve the prognosis. Here, a 41-year-old female presented with a 6-month history of a mass detected in the chest wall following resection of a right pleural mesothelioma 2 years previously. A fluorodeoxyglucose positron emission tomography/computed tomography scan showed a right chest wall mass with a blurred boundary 8.9 cm × 3.7 cm in size. The patient had received one cycle of bevacizumab, carboplatin, and pemetrexed, and two cycles of nivolumab, ipilimumab, and gemcitabine 5 months before admission. We subsequently resected the tumor, the involved diaphragm, and the fifth and sixth ribs, and titanium mesh and continuous suture were used to close the thoracic cage. The fixed paraffin-embedded tissues showed epithelioid pleural mesothelioma. The patient received nivolumab and ipilimumab postoperatively, and no recurrence was detected 16 months after surgery. En bloc resection with reconstructive surgery effectively removed the locally advanced malignancy and restored the biological function of the thorax with a favorable prognosis. Neoadjuvant immunotherapy might therefore be conducive to radical resection and perioperative immunotherapy might improve the prognosis.

[Diagnosis and treatment of malignant mesothelioma of the tunica vaginalis testis: a series of 7 cases].

Objective: To investigate the clinical features, diagnosis, prognosis of malignant mesothelioma of the tunica vaginalis testis (MMTVT). Methods: The clinicopathological data of 7 patients with MMTVT who treated at Sun Yat-sen University Cancer Center between January 2010 and October 2022 were retrospectively reviewed. Cases were first diagnosed at (M (IQR)) 49 (23) years old (range: 27 to 64 years old). The main clinical manifestations were scrotal enlargement (7 cases) and hydrocele (2 cases). Results: Three patients underwent radical orchiectomy as initial treatment, 2 cases underwent hydrocelectomy due to diagnosis of hydrocele, followed by radical orchiectomy at Sun Yat-sen University Cancer Center, and 2 cases underwent transscrotal orchiectomy. Common tumor markers of testicular cancer were not significantly elevated in MMTVT. The expression of tumor PD-L1 was positive in 2 out of the 3 cases. One patient received adjuvant chemotherapy and 2 patients received first-line chemotherapy after tumor recurrence. Chemotherapy regimens used include cisplatin+pemetrexed. Up to October 2022, 3 cases relapsed, of which 2 cases died. The median overall survival was 35 months (range: 4 to 87 months) and the median progression-free survival was 6 months (range: 2 to 87 months). Conclusions: MMTVT at early stage should be treated with early radical orchiectomy and followed up closely after surgery. The cisplatin+pemetrexed regimen is a common option for the treatment of metastatic MMTVT, while whether immune checkpoint inhibitors could serve as a second-line treatment option deserves further research.

Laser ablation-inductively coupled plasma-mass spectrometry analysis reveals differences in chemotherapeutic drug distribution in surgically resected pleural mesothelioma.

AIMS: Pleural mesothelioma (PM) is a highly aggressive thoracic tumour with poor prognosis. Although reduced tissue drug accumulation is one of the key features of platinum (Pt) resistance, little is known about Pt distribution in human PM. METHODS: We assessed Pt levels of blood samples and surgically resected specimens from 25 PM patients who had received neoadjuvant Pt-based chemotherapy (CHT). Pt levels and tissue distributions were measured by laser ablation-inductively coupled plasma-mass spectrometry and correlated with clinicopathological features. RESULTS: In surgically resected PM specimens, mean Pt levels of nontumourous (fibrotic) areas were significantly higher (vs tumourous regions, P = 0.0031). No major heterogeneity of Pt distribution was seen within the tumourous areas. Pt levels correlated neither with the microvessel area nor with apoptosis rate in the tumourous or nontumourous regions. A significant positive correlation was found between serum and both full tissue section and tumourous area mean Pt levels (r = 0.532, P = 0.006, 95% confidence interval [95% CI] 0.161-0.771 and r = 0.415, P = 0.039, 95% CI 0.011-0.702, respectively). Furthermore, a significant negative correlation was detected between serum Pt concentrations and elapsed time from the last cycle of CHT (r = -0.474, P = 0.017, 95% CI -0.738--0.084). Serum Pt levels correlated negatively with overall survival (OS) (P = 0.029). CONCLUSIONS: There are major differences in drug distribution between tumourous and nontumourous areas of PM specimens. Serum Pt levels significantly correlate with full section and tumourous area average Pt levels, elapsed time from the last CHT cycle, and OS. Further studies investigating clinicopathological factors that modulate tissue Pt concentration and distribution are warranted.

European Epidemiology of Pleural Mesothelioma-Real-Life Data From a Joint Analysis of the Mesoscape Database of the European Thoracic Oncology Platform and the European Society of Thoracic Surgery Mesothelioma Database.

INTRODUCTION: Pleural mesothelioma (PM) is an aggressive malignancy with increasing prevalence and poor prognosis. Real-life data are a unique approach to reflect the reality of PM epidemiology, treatment, and prognosis in Europe. METHODS: A joint analysis of the European Thoracic Oncology Platform Mesoscape and the European Society of Thoracic Surgeons (ESTS) databases was performed to better understand the characteristics and epidemiology of PM, including histologic subtype, staging, and treatment. Overall survival (OS) was assessed, adjusting for parameters of clinical interest. RESULTS: The analysis included 2766 patients (Mesoscape: 497/10 centers/ESTS: 2269/77 centers). The primary histologic subtype was epithelioid (71%), with 57% patients on stages III to IV. Within Mesoscape, the patients received either multimodality (59%) or palliative intention treatment (41%). The median follow-up was 47.2 months, on the basis of 1103 patients (Mesoscape: 491/ESTS: 612), with 823 deaths, and median OS was 17.4 months. In multivariable analysis, female sex, epithelioid subtype, and lower stage were associated with longer OS, when stratifying by cohort, age, and Eastern Cooperative Oncology Group Performance Status. Within Mesoscape, multimodality treatment including surgery was predictive of longer OS (hazard ratio = 0.56, 95% confidence interval: 0.45-0.69), adjusting for sex, histologic subtype, and Eastern Cooperative Oncology Group Performance Status. Overall, surgical candidates with a macroscopic complete resection had a significantly longer median OS compared with patients with R2 (25.2 m versus 16.4 m; log-rank p < 0.001). CONCLUSIONS: This combined European Thoracic Oncology Platform/ESTS database analysis offers one of the largest databases with detailed clinical and pathologic outcome. Our finding reflects a benefit for selected patients that undergo multimodality treatment, including macroscopic complete resection, and represents a valuable resource to inform the epidemiology and treatment options for individual patients.

Establishment of a Bayesian network model to predict the survival of malignant peritoneal mesothelioma patients after cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy.

OBJECTIVES: To establish a Bayesian network (BN) model to predict the survival of patients with malignant peritoneal mesothelioma (MPM) treated with cytoreductive surgery (CRS) plus hyperthermic intraperitoneal chemotherapy (HIPEC). METHODS: The clinicopathological data of 154 MPM patients treated with CRS + HIPEC at our hospital from April 2015 to November 2022 were retrospectively analyzed. They were randomly divided into two groups in a 7:3 ratio. Survival analysis was conducted on the training set and a BN model was established. The accuracy of the model was validated using a confusion matrix of the testing set. The receiver operating characteristic (ROC) curve and area under the curve were used to evaluate the overall performance of the BN model. RESULTS: Survival analysis of 107 patients (69.5%) in the training set found ten factors affecting patient prognosis: age, Karnofsky performance score, surgical history, ascites volume, peritoneal cancer index, organ resections, red blood cell transfusion, pathological types, lymphatic metastasis, and Ki-67 index (all p < 0.05). The BN model was successfully established after the above factors were included, and the BN model structure was adjusted according to previous research and clinical experience. The results of confusion matrix obtained by internal validation of 47 cases in the testing set showed that the accuracy of BN model was 72.7%, and the area under ROC was 0.74. CONCLUSIONS: The BN model was established successfully with good overall performance and can be used as a clinical decision reference.

Clinically Occult Diffuse Pleural Mesothelioma in Patients Presenting With Spontaneous Pneumothorax.

OBJECTIVES: To report histologic features of unsuspected diffuse pleural mesothelioma (DPM) in surgical specimens for pneumothorax and demonstrate how ancillary markers support a diagnosis of malignancy in this context. We explored whether pneumothorax may be a clinical manifestation of mesothelioma in situ (MIS). METHODS: A single-institution database search identified patients who underwent surgical resection for spontaneous pneumothorax (n = 229) and/or were diagnosed with DPM (n = 88) from 2000 to 2020. RESULTS: Spontaneous pneumothorax without clinical, radiologic, or intraoperative suspicion of mesothelioma was the initial presentation in 2 (2.3%) of 88 patients diagnosed with DPM. This represented 0.9% (2/229) of all patients undergoing surgical management of pneumothorax but accounted for a larger proportion of older patients (12.5% older than 70 years). Immunohistochemistry for BAP-1 and/or MTAP confirmed the diagnosis of DPM in 2 cases. Mesothelioma in situ was identified retrospectively by immunohistochemistry in 1 case of spontaneous pneumothorax from a 77-year-old man who developed invasive DPM 25 months later. No additional cases of MIS were identified in 19 surgical lung resections for spontaneous pneumothorax. CONCLUSIONS: Histologic examination of bleb resections with ancillary testing for cases with ambiguous features is essential for detection of early DPM. It is uncertain whether spontaneous pneumothorax may represent a clinical manifestation of MIS.

Surgical phenotype of patients with peritoneal mesothelioma and a germline mutation.

BACKGROUND: This study aimed to investigate if peritoneal mesothelioma (PM) patients with germline mutations (GM) have distinct surgical characteristics when compared to those without GM. METHODS: PM patients were selected from an ongoing prospective study that conducts germline testing of 82 susceptibility genes. Germline status was correlated with surgical data obtained from a prospectively collected database using univariate, multivariate, and receiver operating characteristic (ROC) analyses. RESULTS: Out of 88 PM patients enrolled between 2009 and 2019, 18 GMs (20.5%) were identified in BRCA1-associated protein 1 (BAP1) (n = 11, 12.5% of all patients), SDHA (n = 2) and WT1, CDKN2A, CHEK2, ATM, and BRCA2 (n = 1 patient each). Surgical procedures were performed in 71 patients, the most common of which were cytoreductive surgeries with hyperthermic intraperitoneal chemotherapy (n = 61). Patients with GM presented with a higher prevalence of other prior cancers (61.1% vs. 31.4%, p = .02) and lower platelet count (251 [160-413] vs. 367 [196-780] K/µL, p = .005) compared to those without GM (n = 70). Survival outcomes did not differ significantly between the groups. Patients with BAP1 GMs were more likely to develop bicavitary disease and to present with lower platelet count and mitotic count score, and higher peritoneal cancer index (PCI, all p ≤ .04) compared with those without GM. On ROC analysis, the combination of PCI, platelet count and mitotic score yielded an area under the curve of 0.96 (95% CI, 0.91-1.0) for BAP1 GM detection among operated PM patients. CONCLUSION: Higher intraoperative tumor burden and lower platelet count and mitotic score are suggestive of BAP1 GMs in surgical PM patients and should prompt germline testing.

Individualized prediction of survival benefit from postoperative radiotherapy for patients with malignant pleural mesothelioma.

OBJECTIVES: The role of postoperative radiotherapy (PORT) in malignant pleural mesothelioma (MPM) remains controversial and the eighth edition TNM staging scheme for MPM has not been fully verified. We aimed to develop an individualized prediction model for identifying optimal candidates for PORT among MPM patients who received surgery plus chemotherapy and externally validate the performance of the new TNM staging scheme. MATERIALS AND METHODS: Detailed characteristics of MPM patients during 2004-2015 were retrieved from SEER registries. Propensity score matching (PSM) was conducted to reduce disparities of baseline characteristics (age, sex, histologic type, stage, and type of surgery) between the PORT group and no-PORT group. A novel nomogram was constructed based on independent prognosticators identified by multivariate Cox regression model. The discriminatory performance and degree of calibration were evaluated. We stratified patients into different risk groups according to nomogram total scores and estimated the survival benefit of PORT in different subgroups in order to identify the optimal candidates. RESULTS: We identified 596 MPM patients, among which 190 patients (31.9%) received PORT. PORT conferred significant survival benefit in the unmatched population, while there was no significant survival difference favoring PORT in the matched population. The C-index of the new TNM staging scheme was closed to 0.5, which represented a poor discriminatory ability. A novel nomogram was constructed based on clinicopathological factors, including age, sex, histology, and N stage. We stratified patients into three risk groups. Subgroup analyses indicated that PORT was beneficial for high-risk group (p = 0.003) rather than low-risk group (p = 0.965) and intermediate-risk group (p = 0.661). CONCLUSION: We established a novel predictive model, which could make individualized prediction of survival benefit of PORT for MPM and could compensate for weakness in TNM staging system.

Disparities in Survival Due to Social Determinants of Health and Access to Treatment in US Patients With Operable Malignant Pleural Mesothelioma.

Importance: Outcomes of localized malignant pleural mesothelioma (MPM) remain poor despite multimodality therapy. It is unclear what role disparities have in the overall survival (OS) of patients with operable MPM. Objective: To examine survival disparities associated with social determinants of health (SDOHs) and treatment access in patients with malignant pleural mesothelioma. Design, Setting, and Participants: In this observational, retrospective cohort study, patients with MPM diagnosed between January 1, 2004, and December 31, 2017, were identified from the National Cancer Database with a maximum follow-up time of 13.6 years. The analysis was conducted from February 16, 2022, to July 29, 2022. Patients were included if they were diagnosed with potentially resectable clinical stage I to IIIA MPM, had epithelioid and biphasic histologic subtypes, and received chemotherapy. Patients were excluded if they could not receive curative surgery, were 75 years or older, or had metastasis, unknown stage, or tumor extension to the chest wall, mediastinal tissues, or organs. Exposures: Chemotherapy alone vs chemotherapy with curative surgery in the form of pleurectomy and decortication or extrapleural pneumonectomy. Main Outcomes and Measures: The primary end point was OS. Cox proportional hazards regression models were used to determine hazard ratios (HRs) for OS, including univariable and multivariable models controlling for potential confounders, including demographic, comorbidity, clinical, treatment, tumor, and hospital-related variables, as well as SDOHs. Results: A total of 1389 patients with MPM were identified (median [IQR] age, 66 [61-70] years; 1024 [74%] male; 12 [1%] Asian, 49 [3%] Black, 74 [5%] Hispanic, 1233 [89%] White, and 21 [2%] of other race). The median OS was 1.7 years (95% CI, 1.6-1.8). Risk factors associated with worse OS included older age, male sex, Black race, low income, and low educational attainment. Factors associated with greater odds of survival included receipt of surgical therapy, recent year of treatment, increased distance to travel, and treatment at high-volume academic hospitals. The risk factors most strongly associated with poor OS included Black race (HR, 1.96; 95% CI, 1.43-2.69) and male sex (HR, 1.60; 95% CI, 1.38-1.86). Surgical treatment in addition to systemic chemotherapy (HR, 0.70; 95% CI, 0.61-0.81) was independently associated with improved OS, as were chemotherapy initiation (HR, 0.93; 95% CI, 0.87-0.99) and greater travel distance from the hospital (HR, 0.92; 95% CI, 0.86-0.98). Conclusions and Relevance: In this retrospective cohort study of patients with operable MPM, there was significant variability in access to care by SDOHs. Addressing disparities in access to multimodality therapy can help ensure equity of care for patients with MPM.