Robotic-Assisted Pleurectomy is a Safe and Effective Surgical Treatment for Spontaneous Pneumothorax.

INTRODUCTION: Spontaneous pneumothorax is a common thoracic surgical problem. To prevent recurrence, surgical options include blebectomy, mechanical or chemical pleurodesis, pleurectomy, or a combination of these operations. Pleurectomy is associated with lower recurrence rates but may be technically challenging via video-assisted thoracoscopic surgery. We report the first series of robotic-assisted pleurectomy (RAP) for spontaneous pneumothorax. METHODS: A retrospective, single-center analysis was conducted on consecutive patients undergoing RAP for spontaneous pneumothorax from 2017 to 2023. Patients with prior surgery on the same side for pneumothorax were excluded. Demographics, comorbidities, functional status, intraoperative and perioperative variables were collected. 30-d readmission, 30-d mortality, and recurrence were recorded. RESULTS: Thirty-six patients underwent RAP during the study period with a median follow-up of 36 mo. Patients had a median age of 41.5 (interquartile range [IQR] 21.5-68) y and were mostly male (80.6%) and past smokers (44.4%) with 66.6% having a primary spontaneous pneumothorax. The median time to chest tube removal was 3 d (IQR 2-3) and the median length of stay was two days (IQR 2-4). Complications occurred in seven patients with the majority (85.7%) having a grade 2 Clavien-Dindo classification score. There was no 30-d mortality or recurrence. CONCLUSIONS: Robotic-assisted pleurectomy for spontaneous pneumothorax is a safe and effective operation that can be used to prevent future recurrence.

Postoperative early laboratory changes and follow-up process of patients underwent hyperthermic intrathoracic chemotherapy.

BACKGROUND: The aim of combining hyperthermic intrathoracic chemotherapy (HITHOC) with surgery is to achieve local control in patients with pleural malignancies. Liver and kidney dysfunction resulting from this procedure have been reported in the literature. The objective of the study is to examine whether the laboratory abnormalities observed during the initial period persist until day 30. METHODS: The study conducted a retrospective analysis of the blood glucose levels, renal function markers, and hepatic function markers of 30 patients who underwent pleurectomy-decortication and HITHOC for pleural mesothelioma from January 2010 to April 2022. The measurements were taken in the postoperative period on the first four and 30th days. The study analyzed the initial and final laboratory results caused by the procedure. RESULTS: Out of the total of 30 patients, 29, 28, 14, and 12 patients had elevated glucose levels on the first four days after the surgery, respectively. There was no association between glucose abnormalities and preoperative-postoperative diabetes mellitus. A minority of patients experienced atypical alterations in kidney and liver functions during the initial postoperative period. There was no apparent relationship between the renal and hepatic functions in the early and late periods after the surgery. CONCLUSION: Although there were fluctuations in glucose levels and renal and hepatic functions in the early period after surgery, there were no persistent alterations in these parameters by day 30. Elevated glucose levels during the early period were not associated with the development of newly diagnosed diabetes mellitus after surgery. The findings of our study provide evidence that HITHOC is a favorable and well-tolerated treatment option for mesothelioma.

An Evaluation of the Content Quality, Readability, and Reliability of Publicly Available Web-Based Information on Pneumothorax Surgery in Ireland.

Introduction The internet is increasingly the first port of call for patients introduced to new treatments. Unfortunately, many websites are of poor quality, thereby limiting patients' ability to make informed health decisions. Within thoracic surgery, the treatment options for pneumothoraces may be less intuitive for patients to understand compared to procedures such as lobectomies and wedge resections. Therefore, patients must receive high-quality information to make informed treatment decisions. No study to date has evaluated online information regarding pneumothorax surgery. Knowledge regarding the same may allow physicians to recommend appropriate websites to patients and supplement remaining knowledge gaps. Objective This study aims to evaluate the content, readability, and reliability of online information regarding pneumothorax surgery. Methods A total of 11 search terms including "pneumothorax surgery," "pleurectomy," and "pleurodesis" were each entered into Google, Bing, and Yahoo. The top 20 websites found through each search were screened, yielding 660 websites. Only free websites designed for patient consumption that provided information on pneumothorax surgery were included. This criterion excluded 581 websites, leaving 79 websites to be evaluated. To evaluate website reliability, the Journal of American Medical Association (JAMA) and DISCERN benchmark criteria were applied. To evaluate the readability, 10 standardized tools were utilized including the Flesch-Kincaid Reading Ease Score. To evaluate website content, a novel, self-designed 10-part questionnaire was utilized to assess whether information deemed essential by the authors was included. It evaluated whether websites comprehensively described the surgery process for patients, including pre- and post-operative care. Website authorship and year of publication were also noted. Results The mean JAMA score was 1.69 ± 1.29 out of 4, with only nine websites achieving all four reliability criteria. The median readability score was 13.42 (IQR: 11.48-16.23), which corresponded to a 13th-14th school grade standard. Only four websites were written at a sixth-grade reading level. In the novel content questionnaire, 31.6% of websites (n = 25) did not mention any side effects of pneumothorax surgery. Similarly, 39.2% (n = 31) did not mention alternative treatment options. There was no correlation between the date of website update and JAMA (r = 0.158, p = 0.123), DISCERN (r = 0.098, p = 0.341), or readability (r = 0.053, p = 0.606) scores. Conclusion Most websites were written above the sixth-grade reading level, as recommended by the US Department of Health and Human Services. Furthermore, the exclusion of essential information regarding pneumothorax surgery from websites highlights the current gaps in online information. These findings emphasize the need to create and disseminate comprehensive, reliable websites on pneumothorax surgery that enable patients to make informed health decisions.

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

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

Should Treatment of Mesothelioma Include Surgery? MARS2 Fails to Land.

The presentation of the Mesothelioma and Radical Surgery 2 trial, a randomized controlled trial comparing pleurectomy/decortication to no surgery, injected new data into the contentious discussion surrounding the use of surgery in the management of diffuse pleural mesothelioma. We review the trial results in the context of the existing work surrounding the use of surgery in pleural mesothelioma.

[Treatment of malignant effusion]. / Sravnitel'naya kharakteristika metodov lecheniya metastaticheskogo plevrita (obzor literatury).

Malignant effusion complicates more than 15% of all cancers in delayed stages of progression. The most common causes of metastatic pleuritis are lung cancer, breast cancer, ovarian cancer, lymphoproliferative diseases or dissemination of gastrointestinal tumors. Malignant effusion is associated with negative prognosis for overall survival regardless of etiology of tumor, significantly complicates the course of the underlying disease, impairs life quality and complicates treatment. Despite various methods for pleural cavity obliteration in recurrent metastatic pleuritis, there is still no a uniform approach to choosing the optimal treatment strategy. We analyzed the main methods of conservative and surgical treatment of recurrent metastatic pleuritic regarding efficacy, risk of recurrence and reproducibility.

Treating Spontaneous Pneumothorax Using an Innovative Surgical Technique Called Capnodissection Pleurectomy: Case Report.

Spontaneous pneumothorax is one of the most common conditions encountered in thoracic surgery. This condition can be treated conservatively or surgically based on indications and guidelines. Traditional surgical management includes pleurodesis (mechanical or chemical) in addition to bullectomy if the bullae can be identified. Mechanical pleurodesis is usually performed by surgical pleurectomy or pleural abrasion. In this case report, we present a case of a young patient with spontaneous pneumothorax who needed a surgical intervention. We performed a new, innovative surgical technique for surgical pleurectomy where we used carbon dioxide for dissection of the parietal pleura (capnodissection). This technique may provide similar efficiency to the traditional procedure but with less risk of bleeding and complications.

Uniportal versus multiportal video-assisted thoracoscopic surgery for spontaneous pneumothorax.

BACKGROUND: Multiportal video-assisted thoracic surgery (mVATS) is the standard approach for the surgical treatment of spontaneous pneumothorax. However, uniportal VATS (uVATS) has emerged as an alternative aiming to minimize surgical morbidity. This study aims to strengthen the evidence on the safety and efficiency of uVATS compared to mVATS. METHODS: From January 2004 to December 2020, records of patients who had undergone surgical treatment for primary or secondary spontaneous pneumothorax were evaluated for eligibility. Patients who had undergone pleurectomy combined with bullectomy or apical wedge resection via uVATS or mVATS were included. Surgical characteristics and postoperative data were compared between patients who had undergone surgery via uVATS or mVATS. Univariable and multivariable analyses were performed to determine whether the surgical approach was associated with any complication (primary outcome), major complications (i.e., Clavien-Dindo ≥ 3), recurrence, prolonged hospitalization or prolonged chest drainage duration (secondary outcomes). RESULTS: A total of 212 patients were enrolled. Patients treated via uVATS (n = 71) and mVATS (n = 141) were significantly different in pneumothorax type (secondary spontaneous; uVATS: 54 [76%], mVATS: 79 [56%]; p = 0.004). No significant differences were observed in (major) complications and recurrence rates between both groups. Multivariable analyses revealed that the surgical approach was no significant predictor for the primary or secondary outcomes. CONCLUSIONS: This study indicates that uVATS is non-inferior to mVATS in the surgical treatment of spontaneous pneumothorax regarding safety and efficiency, and thus the uVATS approach has the potential for further improvements in the perioperative surgical care for spontaneous pneumothorax.

The Role of Surgery in Pleural Mesothelioma.

Surgery plays a central role in the diagnosis, staging, and management of pleural mesothelioma. Achieving an accurate diagnosis through surgical intervention and identifying the specific histologic subtype is crucial for determining the appropriate course of treatment. The histologic subtype guides decisions regarding the use of chemotherapy, immunotherapy, or multimodality treatment. The goal of surgery as part of multimodality treatment is to accomplish macroscopic complete resection with the eradication of grossly visible and palpable disease. Over the past two decades, many medical centers worldwide have shifted from performing extra-pleural pneumonectomy (EPP) to pleurectomy decortication (PD). This transition is motivated by the lower rates of short-term mortality and morbidity associated with PD and similar or even better long-term survival outcomes, compared to EPP. This review aims to outline the role of surgery in diagnosing, staging, and treating patients with pleural mesothelioma.

Aerostasis to limit air leak following extended pleurectomy-decortication.

Extended pleurectomy-decortication is a cytoreductive surgical treatment for malignant pleural mesothelioma. Prolonged air leak remains a major postoperative challenge, lengthening hospital stay and increasing morbidity. In this video report, we present a stepwise approach for visceral decortication and introduce the concept of aerostasis by construction of an artificial neopleura. Our results suggest that improved aerostasis results in shortened air leak duration.

Prolonged survival and novel prognostic factors in women with pleural mesothelioma treated with extended pleurectomy decortication.

Background: Pleural mesothelioma (PM) is an uncommon and extremely aggressive malignancy associated with past exposure to asbestos. The low representation of women among PM patients is likely due to differences in occupational asbestos exposure. Due to the controversial role of female sex as a prognostic factor in PM, the study aims to evaluate the survival of females treated with lung-sparing surgery. We present a cohort of 114 consecutive female patients with PM who underwent intended extended pleurectomy decortication (ePD) over 11 years in a high-volume single institution. Methods: All women from 2007-2017 who underwent intended ePD were enrolled in the study. Data on clinical, operative, and outcome were collected. Kaplan-Meier estimators and log-rank tests were employed to assess the overall survival, and Cox regression models were utilized to analyze prognostic factors. Results: During the study period, 454 patients underwent thoracotomy with intended ePD in a single institution. There were 114 females (25%), and macroscopic complete resection (MCR) was achieved in 97 (85.1%). The median age was 65 years, histology was epithelioid in 81 (71.0%), biphasic in 31 (27.2%), and sarcomatoid in 2 (1.8%). The 30- and 90-day mortality were 3.5% and 6.1%, respectively. Median survival in females was 38 months, and 5-year survival was 28.2%. The median survival and 5-year survival rate for patients with epithelioid histology and MCR were 44.4 months and 36.4%, respectively. In a univariate analysis, several factors were found to be associated with patient overall survival including MCR [hazard ratio (HR): 0.3, P<0.001], early T status (HR: 1.6, P=0.03), adjuvant therapy (HR: 0.5, P=0.006), intraoperative heated chemotherapy (IOHC) (HR: 0.8, P=0.03), age (HR: 1.02, P=0.03) and epithelioid histology (HR: 0.5, P=0.009). Conclusions: For women with epithelioid PM undergoing intended ePD within a multimodal setting, prolonged survival is anticipated.

Malignant pleural mesothelioma: Description of pleural decortication and hyperthermic chemotherapy technique in multimodal therapy.

The current treatment for mesothelioma, in selected cases, consists of extended pleurodecortication and intrathoracic hyperthermic chemotherapy. This technique is laborious and detailed and must be followed step by step to achieve good results. We present the case of a patient with epithelioid mesothelioma meeting surgical criteria who underwent the mentioned technique, experiencing an adequate postoperative period and an early discharge. This experience demonstrates that the technique is safe when performed in centres with experience and the means to address this complex pathology.

Circulating SMRP and CA-125 before and after pleurectomy decortication for pleural mesothelioma.

BACKGROUND: Tumor recurrence remains the main barrier to survival after surgery for pleural mesothelioma (PM). Soluble mesothelin-related protein (SMRP) and cancer antigen 125 (CA-125) are established blood-based biomarkers for monitoring PM. We prospectively studied the utility of these biomarkers after pleurectomy decortication (PD). METHODS: Patients who underwent PD and achieved complete macroscopic resection with available preoperative SMRP levels were included. Tumor marker levels were determined within 60 days of three timepoints: (1) preoperation, (2) post-operation, and (3) recurrence. RESULTS: Of 356 evaluable patients, 276 (78%) had recurrence by the end of follow-up interval. Elevated preoperative SMRP levels were associated with epithelioid histology (p < 0.013), advanced TNM (p < 0.001) stage, and clinical stage (p < 0.001). Preoperative CA-125 levels were not significantly associated with clinical covariates. Neither biomarker was associated with survival or disease-free survival. With respect to nonpleural and nonlymphatic recurrences, mean SMRP levels were elevated in patients with pleural (p = 0.021) and lymph node (p = 0.042) recurrences. CA-125 levels were significantly higher in patients with abdominal (p < 0.001) and lymph node (p = 0.004) recurrences. Among patients with all three timepoints available, we observed an average decrease in SMRP levels by 1.93 nmol/L (p < 0.001) postoperatively and again an average increase at recurrence by 0.79 nmol/L (p < 0.001). There were no significant changes in levels of CA-125 across the study timepoints (p = 0.47). CONCLUSIONS: Longitudinal changes in SMRP levels corresponded with a radiographic presence of disease in a subset of patients. SMRP surveillance could aid in detection of local recurrences, whereas CA-125 could be helpful in recognizing abdominal recurrences.

Investigation of the appropriate viscosity of fibrinogen in repairing pleural defects using ventilation and anchoring in an ex vivo pig model.

OBJECTIVE: Our previous study revealed that the viscosity of fibrinogen could influence the effectiveness of ventilation and anchoring (V/A) methods for controlling air leakages. Here, we examined the association between the viscosity of fibrinogen and effectiveness using an ex vivo pig model. METHODS: The fibrin glue used in this study was BOLHEAL® (KM Biologics Co., Ltd., Kumamoto, Japan). We prepared three types of fibrinogen with different viscosities (higher and lower than normal), including one without additives. Using an ex vivo pig model, a pleural defect was made, and the defect was repaired using three different viscosities of fibrinogen through the V/A method. We measured the rupture pressure at the repair site (N = 10) and histologically evaluated the depth of fibrin infiltration into the lung parenchyma at the repair sites. RESULTS: The median rupture pressure was 51.5 (40-73) cmH2O in Group 1 (lower viscosity), 47.0 (47-88) cmH2O in Group 2 (no change in viscosity), and 35.5 (25-61) cmH2O in Group 3 (higher viscosity). There was no statistically significant difference between Groups 1 and 2 (p = 0.819), but the rupture pressure was significantly higher in Group 2 than in Group 3 (p = 0.0136). Histological evaluation revealed deep infiltration of fibrin into the lung parenchyma in Groups 1 and 2, but no such infiltration was observed in the higher-viscosity group. CONCLUSIONS: The results of this experiment suggested that the V/A method using fibrin glue containing low-viscosity fibrinogen was more effective in controlling air leakage due to pleural defects.

The International Association for the Study of Lung Cancer Pleural Mesothelioma Staging Project: Expanded Database to Inform Revisions in the Ninth Edition of the TNM Classification of Pleural Mesothelioma.

The International Association for the Study of Lung Cancer collaborated with the International Mesothelioma Interest Group to propose the first TNM stage classification system for diffuse pleural mesothelioma in 1995, accepted by the Union for International Cancer Control and the American Joint Committee on Cancer for the sixth and seventh edition stage classification manuals. The International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee Mesothelioma Domain developed and analyzed an international registry of patients with pleural mesothelioma and updated TNM descriptors for the eighth edition of the stage classification system. To inform revisions for the forthcoming ninth edition of the TNM stage classification system, data submission was solicited for patients diagnosed between 2013 and 2022 with expanded data elements on the basis of the first project's exploratory analyses, including pleural thickness measurements, updated surgical nomenclature, and molecular markers. The resulting database consisted of a total of 3598 analyzable cases from Europe, Australia, Asia, North America, and South America, with a median age of 71 years (range: 18-99 y), 2775 (77.1%) of whom were men. With only 1310 patients (36.4%) undergoing curative-intent operations, this iteration of the database includes far more patients treated nonsurgically compared with prior. Four separate manuscripts on T, N, M, and stage groupings submitted to this journal will summarize analyses of these data and will serve collectively as the primary source of the proposed changes to the upcoming ninth edition of the pleural mesothelioma stage classification system.

A case of attempted transbronchial spigot insertion for fistulous pyothorax in the residual pleural airspace after pleurectomy/decortication for malignant pleural mesothelioma.

Pleurectomy/decortication for malignant pleural mesothelioma is a relatively recent surgical approach for which there is a dearth of information on complications, especially in the late postoperative period. A 70-year-old man was diagnosed with right epithelioid malignant pleural mesothelioma and underwent pleurectomy/decortication. Computed tomography at 6 months after surgery revealed nodules on the surface of the right lung. These nodules gradually increased in size and were diagnosed as recurrent disease. Immunotherapy was started, but treatment was discontinued a few days after the first course due to pneumonitis. Subsequent oral prednisolone therapy for about 2 months ameliorated pneumonitis, but fistulous pyothorax developed. During attempted transbronchial occlusion of the responsible bronchus, some spigots penetrated the empyema cavity. Open window thoracotomy was performed on the following day. This case suggests that if there is no change in diameter between the proximal and distal parts of the responsible bronchus, transbronchial occlusion should not be chosen.

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.

Uniportal thoracoscopic bullectomy with improved parietal pleurectomy for primary spontaneous pneumothorax.

INTRODUCTION: Parietal pleurectomy with bullectomy has been established as an effective method for preventing the recurrence of primary spontaneous pneumothorax (PSP). Our center introduced enhanced technical measures in uniportal thoracoscopic parietal pleurectomy with bullectomy for patients with PSP, aiming to document our initial experience and assess the procedure's effectiveness in preventing the recurrence of PSP. METHODS: We analyzed the clinical data of 86 patients with PSP who underwent the improved uniportal thoracoscopic parietal pleurectomy with bullectomy between July 2019 and August 2022. During the procedure, the parietal pleura above the second intercostal space was stripped but not removed. Instead, it was retained in the thoracic cavity using a piece of pedunculated pleura. Subsequently, the stumps of the lung were covered by the preserved parietal pleura. RESULTS: The results of the study showed that the mean operative time was 59.87 ± 16.93 min, and the postoperative drainage duration averaged 3.94 ± 2.17 days. The mean intraoperative blood loss was 24.33 ± 48.91 ml, and the mean postoperative drainage volume was 289.00 ± 170.03 ml. Prolonged air leakage for more than 5 days was observed in five patients (5.81%), but no other postoperative complications were recorded. During the follow-up, one patient (1.16%) experienced a recurrence of pneumothorax. CONCLUSIONS: The perioperative results of bullectomy with the improved pleurectomy technique are deemed satisfactory. The various technical steps attempted at our center are found to be feasible and safe, and they may contribute to reducing the rates of recurrence in PSP.

Perioperative discordance in mesothelioma cell type after pleurectomy/decortication-a possible detrimental effect of neoadjuvant chemotherapy due to epithelial to mesenchymal transition?

OBJECTIVES: The goal was to evaluate the accuracy of preoperative histological assessment and the factors affecting the accuracy and the subsequent effect on postoperative survival after surgical treatment for malignant pleural mesothelioma (MPM). METHODS: We analysed the perioperative course of patients who underwent surgery for MPM in a single institution over a 5-year period. The primary end point was to evaluate the proportion of histological discordance between preoperative assessment and postoperative histological diagnosis. The secondary end point was to evaluate its prognostic effect on postoperative survival after surgical treatment. RESULTS: One-hundred and twenty-nine patients were included in this study. Histological discordance between preoperative assessment and postoperative histological diagnosis was found in 27 of 129 patients (20.9%): epithelial to biphasic/sarcomatoid (negative discordance) in 24 and biphasic to epithelial (positive discordance) in 3 (P-value < 0.001). All 24 patients who exhibited epithelial-to-mesenchymal transition (EMT) had received neoadjuvant chemotherapy (P-value: 0.006). In the 34 patients who underwent upfront surgery, only 1 case (2.9%) of EMT was identified (P-value: 0.127). EMT was not associated with a less invasive method of biopsy (P-value: 0.058) or with the volume or maximum diameter of the biopsy (P-value: 0.358 and 0.518, respectively), but it was significantly associated with the receipt of neoadjuvant chemotherapy (P-value: 0.006). At a median follow-up of 17 months (IQR: 11.0-28.0), 50 (39%) patients are still alive. Overall survival was significantly reduced in those patients who received neoadjuvant chemotherapy and who exhibited discordance (EMT) compared to those who did not: 11 (95% CI: 6.2-15.8) months versus 19 (95% CI: 14.2-23.8) months (P-value < 0.001). In addition, there was no difference in overall survival between those who received neoadjuvant chemotherapy and those who had upfront surgery: 16 (95% CI: 2.5-19.5) months versus 30 (95% CI: 11.6-48.4) months (P-value: 0.203). CONCLUSIONS: The association of neoadjuvant chemotherapy with perioperative histological discordance can be explained by EMT, which leads to worse survival. Therefore, there is an argument for the preferential use of upfront surgery in the treatment of otherwise resectable MPM.

The International Association for the Study of Lung Cancer Pleural Mesothelioma Staging Project: Updated Modeling of Prognostic Factors in Pleural Mesothelioma.

INTRODUCTION: The International Association for the Study of Lung Cancer developed an international pleural mesothelioma database to improve staging. Data entered from 1995 to 2009 (training data set) were analyzed previously to evaluate supplemental prognostic factors. We evaluated these factors with new clinical data to determine whether the previous models could be improved. METHODS: Patients entered into the database from 2009 to 2019 (validation cohort) were assessed for the association between previous prognosticators and overall survival using Cox proportional hazards regression with bidirectional stepwise selection. Additional variables were analyzed and models were compared using Harrell's C-index. RESULTS: The training data set included 3101 patients and the validation cohort, 1733 patients. For the multivariable pathologic staging model applied to the training cohort, C-index was 0.68 (95% confidence interval [CI]: 0.656-0.705). For the validation data set (n = 497), C-index was 0.650 (95% CI: 0.614-0.685), and pathologic stage, histologic diagnosis, sex, adjuvant therapy, and platelet count were independently associated with survival. Adding anemia to the model increased the C-index to 0.652 (95% CI: 0.618-0.686). A basic presentation model including all parameters before staging yielded a C-index of 0.668 (95% CI: 0.641-0.695). In comparison, the European Organization for Research and Treatment of Cancer model yielded C-indices of 0.550 (95% CI: 0.511-0.589) and 0.577 (95% CI: 0.550-0.604) for pathologic staging and presentation models, respectively. CONCLUSIONS: Although significant predictors differed slightly, the International Association for the Study of Lung Cancer training model performed well in the validation set and better than the model of the European Organization for Research and Treatment of Cancer. International collaboration is critical to improve outcomes in this rare disease.