Clinical Outcomes With Recurrence After Pleurectomy/Decortication for Malignant Pleural Mesothelioma

Optimal surgery for resectable malignant pleural mesothelioma in the setting of multimodality treatment

The surgical treatment of malignant pleural mesothelioma (MPM) involves procedures to achieve macroscopic complete resection, depending on the patient's condition. We reviewed the evolution of surgical approaches for resectable MPM. Since surgery is no more than a single step in the set of processes in multimodality treatment (MMT), we concluded that these procedures should give precedence to lung preservation and minimize resection whenever possible. Postoperative quality of life must be prioritized when the patient can receive appropriate adjuvant therapy.

Impact of Operation on Disease Progression and Survival of Patients With Pleural Mesothelioma

BACKGROUND

The effects of surgery on the survival of patients with pleural mesothelioma remain poorly understood. We compared the therapeutic outcomes of patients receiving neoadjuvant chemotherapy, followed by surgery or refusing surgery, for pleural mesothelioma.

METHODS

This retrospective study included consecutive patients who were eligible for curative-intent surgery after 3 cycles of neoadjuvant chemotherapy with platinum plus pemetrexed at our hospital during January 2011 to December 2021. Patients were divided into 2 groups. The surgery group comprised patients who underwent curative-intent surgery for pleural mesothelioma. The refusal-of-surgery group comprised patients who were medically eligible for surgery but refused to consent to surgery. Overall survival and progression-free survival were calculated using the Kaplan-Meier method with the generalized Wilcoxon test.

RESULTS

Of the 296 eligible patients for the study, 272 underwent surgery and 24 refused surgery. During the surgery, 204 patients (75.0%), 43 (15.8%), and 25 (9.2%) underwent pleurectomy/decortication, extrapleural pneumonectomy, and exploratory thoracotomy, respectively. The median follow-up length was 28.4 months. The median overall survival periods were 40.7 months (95% CI, 32.2-45.6 months) for surgery and 23.6 months (95% CI, 15.2-43.0 months) for refusal of surgery (P = .03). The median progression-free survival periods were 20.2 months (95% CI, 17.0-22.5 months) for surgery and 12.9 months (95% CI, 8.3-16.8 months) for refusal of surgery (P < .001).

CONCLUSIONS

Overall survival and progression-free survival were significantly better in surgery than in refusal of surgery. Surgery may improve the survival outcomes of patients with pleural mesothelioma.

Efficacy and safety of nivolumab with ipilimumab for recurrent malignant pleural mesothelioma after primary surgical intervention

BACKGROUND

Treatment of recurrent malignant pleural mesothelioma (MPM) remains challenging. Our study examined the efficacy, tolerability, and safety of nivolumab with ipilimumab treatment for recurrent MPM after primary curative-intent surgery.

METHODS

Treatment comprised 360 mg nivolumab every 3 weeks and 1 mg/kg of ipilimumab every 6 weeks, both administered intravenously. Both were discontinued for progressive disease or serious adverse events (AEs). Additional post-treatment data were evaluated, including objective response rate (ORR), disease control rate (DCR), post-treatment survival, progression-free survival (PFS), and AEs. Tumor response was assessed using the modified Response Evaluation Criteria in Solid Tumors (RECIST 1.1). Survival analysis was estimated using a Kaplan-Meier plot. Feasibility analysis was performed using the National Cancer Institute Common Terminology Criteria for AEs version 5.0.

RESULTS

Forty-one patients received nivolumab with ipilimumab for recurrent MPM after primary curative-intent surgery (median follow-up, 10.4 months; median treatment, 5.1 months). Overall, 18 patients exhibited partial response, 13 exhibited stable disease, and 10 had documented progressive disease. ORR and DCR were 43.9 and 75.6%, respectively. The 12-month post-treatment survival rate and PFS rate were 74.2 and 40.0%, respectively (median survival, not calculated; median PFS, 7.3 months). Further, 47 AEs were reported in 29 patients (70.7%), including grade 3-4 AEs in 14 patients (34.1%). Grade 4 hepatobiliary disorders were observed in 2 patients and grade 4 neutropenia was observed in 1.

CONCLUSION

Nivolumab with ipilimumab treatment in patients with recurrent MPM after primary surgical treatment may be clinically efficacious, although serious AEs may be frequently observed.

Medical application of the monoclonal antibody SKM9-2 against sialylated HEG1, a new precision marker for malignant mesothelioma

Malignant pleural mesothelioma (MPM) is an aggressive tumor of the pleural cavity. Pathologically distinguishing MPM from other pleural lesions is often difficult. We searched for marker antigens to facilitate the pathological diagnosis of MPM and found useful markers for the pathological detection of malignant mesothelioma. Among them, the anti-mesothelioma monoclonal antibody SKM9-2, which was isolated as a clone binding to specimens of MPM (but not to specimens of lung adenocarcinoma) by immunohistochemical screening, showed higher specificity and sensitivity than traditional mesothelioma markers. SKM9-2 recognizes both sialylated O-glycans and peptide sequences in HEG1, and its glycan modifications are specific to mesothelioma. New effective treatments for MPM are needed because the prognosis of patients with MPM is usually poor. SKM9-2 can be used as a seed for next-generation antibody drugs with strong cytotoxic activities. In this review, we have summarized our research on antibody development for MPM diagnosis and treatment.

Long-term outcomes and risk factors of residual thoracic spaces after pleurectomy/decortication for mesothelioma

OBJECTIVES

The residual thoracic spaces (RTS) after pleurectomy/decortication (P/D) remain unexplored to date. Hence, this study aims to examine the details and risk factors of RTS during the 3 post-P/D months.

METHODS

We retrospectively examined patients who underwent neoadjuvant chemotherapy, followed by P/D for malignant pleural mesothelioma from September 2012 to December 2020. The RTS group included cases of residual thoracic cavity unaccompanied by pleural effusion on 3 postoperative months computed tomography. We determined risk factors for RTS using univariable and multivariable analyses.

RESULTS

Of 170 patients examined, 58 (34.1%) were in the RTS group and 112 (65.9%) in the non-RTS group. In the RTS group, 43 patients recovered from RTS during the follow-up period; 4 patients developed chronic fistular empyema, while 2 required fenestration and 2 were thoracoscopic debridement. Besides, 11 patients exhibited RTS continuously. The univariable analysis revealed that compared with the non-RTS group, the RTS group reported a significantly longer postoperative air leak (>7 days; P < 0.01) and right P/D (P = 0.04). The multivariable analysis demonstrated that longer postoperative air leak (>7 days) remained a risk factor for RTS (odds ratio 2.5, 95% confidence interval: 1.3-4.9, P < 0.01).

CONCLUSIONS

RTS was a postoperative event that frequently observed in patients undergoing P/D. Overall, the current study findings suggest longer postoperative air leak (>7 days) as a significant risk factor for RTS.

Incidence and Risk Factors of Chest Wall Metastasis at Biopsy Sites in Patients with Malignant Pleural Mesothelioma

To investigate the incidence and risk factors of chest wall metastasis (CWM) at biopsy sites in patients with malignant pleural mesothelioma (MPM). This retrospective cohort study was conducted in 262 consecutive MPM patients who underwent multimodal treatment in which including neoadjuvant chemotherapy (NAC) and curative-intent surgery, from August 2009 to March 2021. CWM was evaluated radiologically (r-CWM) and pathologically (p-CWM). We also investigated the risk factors of p-CWM and the consistency between r-CWM and p-CWM. Of 262 patients, 25 patients were excluded from analysis due to missing data or impossibility of evaluation. Of the eligible 237 patients, pleural biopsy was performed via video-assisted thoracoscopic surgery in 197 (83.1%) and medical thoracoscopy in 40 (16.9%). Pleurodesis was performed after pleural biopsy in 74 patients (31.2%). All patients received NAC followed by curative-intent surgery. Radiological examination showed r-CWM in 43 patients (18.1%), while pathological examination showed p-CWM in 135 patients (57.0%). The incidence of p-CWM was significantly higher in the patients who received pleurodesis after pleural biopsy (77.0% vs. 47.9%, <0.001). Multivariate logistic regression analysis for p-CWM revealed that pleurodesis is an independent risk factor of p-CWM (adjusted hazard ratio, 3.46; 95% confidence interval, 1.84−6.52, <0.001). CWM at the biopsy site was pathologically proven in more than half of the patients (57.0%) who received NAC followed by curative-intent surgery, which was higher than the numbers diagnosed by radiological examinations (p-CWM: 57.0% vs. r-CWM: 18.1%). Pleurodesis after pleural biopsy is an independent risk factor of p-CWM.

Single-Center 20-Year Experience in Surgical Treatment of Malignant Pleural Mesothelioma

Objectives: We examined a series of malignant pleural mesothelioma (MPM) patients who consecutively underwent surgery in our institution during the last 20 years. Across this period, we changed our surgical approach to MPM, adopting extended pleurectomy and decortication (eP/D) instead of extrapleural pneumonectomy (EPP). In this study, we compare the perioperative outcomes and long-term survival of patients who underwent EPP vs. eP/D. Methods: A retrospective analysis was carried out of all the MPM patients identified from our departmental database who underwent EPP or P/D from 2000 to 2021. Clavien−Dindo criteria was adopted to score postoperative complications, while Kaplan−Meier methods and a Cox multivariable analysis were used to perform the survival analysis. Results: Of 163 patients, 78 (48%) underwent EPP and 85 (52%) eP/D. Induction chemotherapy was significantly administrated more often in the eP/D group (88% vs. 51%). Complete trimodality treatment including induction chemotherapy, radical surgery, and adjuvant radiotherapy was administered in 74% of the eP/D group versus 32% of the EPP group (p < 0.001). The postoperative morbidity rate was higher in the eP/D group (54%) compared to the EPP group (36%) (p = 0.02); no statistically significant differences were identified concerning major complications (EPP 43% vs. eP/D 24%, p = 0.08). No statistical differences were identified in 30-day mortality, 90-day mortality, median disease-free, and overall survival statistics between the two groups. The Cox multivariable analysis confirmed no induction chemotherapy (HR, 0.5; p = 0.002), RDW (HR, 1.08; p = 0.02), and the presence of pathological nodal disease (HR, 1.99; p = 0.001) as factors associated with worse survival in the entire series. Conclusions: Our data support that eP/D is a well-tolerated procedure allowing the implementation of a trimodality strategy (induction chemotherapy, surgery, and radiotherapy) in most MPM patients. When eP/D is offered in this setting, the oncological results are comparable to EPP. To obtain the best oncological results, the goal of surgical resection should be macroscopic complete resection (R0) in carefully selected patients (clinical N0).

Second Surgery for Recurrent Malignant Pleural Mesothelioma after Multimodality Treatment: A Systematic Review

Malignant pleural mesothelioma (MPM) is an aggressive asbestos-related tumour with poor prognosis. To date, a multimodality treatment, including chemotherapy and surgery, with or without radiotherapy, is the gold standard therapy for selected patients with epithelioid and early-stage MPM. In this setting, the goal of surgery is to achieve the macroscopic complete resection, obtained by either extrapleural pneumonectomy or pleurectomy/decortication. Failure, in local and/or distant sites, is one of the major concerns; in fact, there has been no established treatment for the recurrence of MPM after the multimodal approach, and the role of surgery in this context is still controversial. By using electronic databases, studies that included recurrent MPM patients who underwent a second surgery were identified. The endpoints included were: a pattern of recurrence, post-recurrence survival (PRS), and the type of second surgery. When available, factors predicting better PRS and perioperative mortality and morbidity were collected. This systematic review offers an overview of the results that are currently obtained in patients undergoing a second surgery for relapsed MPM, with the aim to provide a comprehensive view on this subject that explores if a second surgery leads to an improvement in survival.

Long-term outcomes after lung-sparing surgery for epithelial mesothelioma

Background

This observational study evaluates retrospectively the long-term outcomes after pleurectomy/decortication for pleural mesothelioma, with and without the resection/reconstruction of diaphragm and pericardium.

Methods

Data from 155 consecutive patients undergoing lung-sparing surgery for epithelial pleural mesothelioma were reviewed. Selection criteria for surgery were cT1-3, cN0-1, good performance status, age <80 years. Perioperative Pemetrexed-Platinum regimen was administered as induction in 101 cases (65.2%) and as adjuvant treatment in 54 cases (34.8%). Extended pleurectomy/decortication was performed in 87 cases (56.12%). In 68 patients (43.87%) standard pleurectomy/decortication was performed without resection/reconstruction of diaphragm and pericardium, when tumour infiltration was deemed absent after intraoperative frozen section. The log-rank test and Cox regression model were used to assess the factors affecting overall survival and recurrence free survival.

Results

Median follow-up was 20 months. The 2- and 5-year survival rate was 60.9% and 29.2% with a median survival of 34 months. An improved survival was observed when standard pleurectomy/decortication was carried out (P=0.007). A significant impact on survival was found comparing the TNM-stages (P=0.001), pT (P=0.002) and pN variables (P=0.001). Multivariate analysis identified the pN-status (P=0.003) and standard pleurectomy/decortication (P=0.017) as predictive for longer survival. The recurrence-free survival >12 months was strongly related to the overall survival (P<0.001). The macroscopic complete resection (P=0.001), TNM-stage (P=0.003) and pT-status (P=0.001) are related to relapse.

Conclusions

Within multimodal management of pleural mesothelioma, lung-sparing surgery is a valid option even with more conservative technique. A benefit for a longer survival was observed in the early stage of disease, with pN0 and when pleurectomy/decortication is carried out, preserving diaphragm and pericardium. Recurrence is not affected by the type of surgery, and a recurrence-free interval >12 months is predictive of an increased survival when the macroscopic complete resection is achieved.

Non-incisional pleurectomy/decortication for malignant mesothelioma after cardiac surgery

A 70‐year‐old man diagnosed with right‐sided malignant epithelial pleural mesothelioma, underwent pleurectomy/decortication after three courses of neoadjuvant chemotherapy. He had a history of mitral valve replacement and maze procedure with median sternotomy, and the procedures resulted in strong adhesion from the apex to the mediastinal side. In particular, the peeling of the area where the tumor invaded the pericardium required the most attention; however, the involved pericardium could be partially resected without damaging the right atrium. Finally, en bloc macroscopic complete resection with the entire pleura was successfully performed without conversion to extrapleural pneumonectomy.

Carbon Dioxide Blower Facilitates Visceral Pleurectomy in Malignant Pleural Mesothelioma

Pleurectomy/decortication serves as a major component of therapy for malignant pleural mesothelioma (MPM), but the procedure is time consuming. We tentatively applied carbon dioxide (CO₂) blower into pleurectomy/decortication for a patient with local relapse of MPM. The blower can help increase the potential subpleural place thanks to the positive pressure by CO₂, while the mist of saline could clean the potential bleeding to increase visibility. Thereby, the procedure was greatly facilitated in a more precise manner, with blood loss of 100ml and acceptable postoperative air leak and thorax drainage. Therefore, CO₂ blower may be considered in pleurectomy/decortication for MPM.

Extended Pleurectomy/Decortication for Malignant Pleural Mesothelioma: Humanitas's Experience

BACKGROUND

We analysed a series of malignant pleural mesothelioma (MPM) patients who consecutively underwent extended Pleurectomy/Decortication (eP/D) in a centre with a high level of thoracic surgery experience (IRCCS Humanitas Research Hospital) to explore postoperative morbidity and mortality, pattern of recurrence and survival.

METHODS

A retrospective analysis was performed on MPM patients underwent eP/D in our centre from 2010 to 2021. All patients were identified from our departmental database. Postoperative complications were scored according to Clavien-Dindo criteria. Survival analysis was performed by the Kaplan-Meier methods and Cox multivariable analysis.

RESULTS

Eighty-five patients underwent extended pleurectomy decortication (eP/D) during study period. Macroscopical residual disease (R2) was reported in one case. A neoadjuvant chemotherapy regiment was administrated in 88% of the surgical cohort. A complete trimodality treatment including induction with platinum agents and pemetrexed, radical cytoreductive surgery and volumetric modulated arc therapy technology (VMAT) could be administered in 63 patients (74%). Postoperative morbidity rate was 54.11%, major complications (defined as Clavien-Dindo ≥ 3) were reported in 11 patients (12.9%). Thirty-day mortality and 90-day mortality were, respectively, 2.35% and 3.53%. Median disease-free and overall survival were, respectively, 13.7 and 25.5 months. The occurrence of major complications (Clavien-Dindo ≥ 3), operative time, pT3-T4, pathological node involvement (pN+) were prognostic factors associated with worse survival.

CONCLUSIONS

In our experience, eP/D is a well-tolerated procedure with acceptable mortality and morbidity, allowing for the administration of trimodality regimens in most patients. eP/D offered in a multimodality treatment setting have satisfactory long term oncological results. To obtain best oncological results the goal of surgery should be macroscopic complete resection in carefully selected patients (clinical N0).

Neoadjuvant pemetrexed plus cisplatin followed by pleurectomy for malignant pleural mesothelioma

PURPOSE

Despite becoming the preferred surgical technique for malignant pleural mesothelioma, pleurectomy/decortication has received few prospective clinical trials. Therefore, the Japan Mesothelioma Interest Group conducted a prospective multi-institutional study to evaluate the feasibility of neoadjuvant chemotherapy followed by pleurectomy/decortication.

METHODS

Patients with histologically confirmed, resectable malignant pleural mesothelioma underwent neoadjuvant chemotherapy comprising pemetrexed 500 mg/m² plus cisplatin 75 mg/m² for 3 cycles, followed by pleurectomy/decortication. The primary end point was macroscopic complete resection rate regardless of the surgical technique used.

RESULTS

Among the 24 patients enrolled, 20 received neoadjuvant chemotherapy and 18 proceeded to surgery, all of whom achieved macroscopic complete resection. Pleurectomy/decortication was performed in 15 patients. The trial satisfied the primary end point, with a macroscopic complete resection rate of 90% (18/20, 95% confidence interval, 68.3-98.8). No treatment-related 30- and 90-day mortality occurred. The overall survival after 1 and 2 years and median overall survival after registration were 95.0% (95% confidence interval, 69.5-99.3), 70.0% (95% confidence interval, 45.1-85.3), and 3.45 years (95% confidence interval, 1.64 to not available), respectively. The cumulative incidence of progression after 1 and 2 years and median time to progression were 33.3% (95% confidence interval, 17.3-64.1), 61.1% (95% confidence interval, 42.3-88.3), and 1.71 years (95% confidence interval, 1.00-2.99), respectively. The best postoperative value for forced expiratory volume was 78.0% of preoperative values.

CONCLUSIONS

Neoadjuvant chemotherapy followed by pleurectomy/decortication was feasible with acceptable survival and mortality/morbidity. Postoperative pulmonary function was approximately 80% of the preoperative pulmonary function.

Orphan Designation and Cisplatin/Hyaluronan Complex in an Intracavitary Film for Malignant Mesothelioma

Pleural mesothelioma is a lung diffuse tumor, whose complete resection is unlikely. Consequently, metastases reappear where the primary tumor was removed. This paper illustrates the orphan medicine designation procedure of an intracavitary cisplatin film and related pharmaceutical development aspects requested by the European Medicines Agency (EMA) in its Scientific Advice. Since cisplatin pharmacokinetics from the implanted film in sheep resulted substantially modified compared to intravenous administration, the formation of a cisplatin/hyaluronan complex had been hypothesized. Here, the interaction between sodium hyaluronate (NaHA) and cisplatin (CisPt) was demonstrated. Size exclusion chromatography qualitatively evidenced the complex in the film-forming mixture, only showing the NaHA peak. Atomic absorption spectroscopy of the corresponding fraction revealed platinum, confirming the interaction. Reverse phase HPLC quantified about 5% free cisplatin in the film-forming mixture, indirectly meaning that 95% was complexed. Finally, a study of CisPt release from the film assessed how CisPt/NaHA complex affected drug availability. In water, a medium without chloride ions, there was no release and the film remained intact for 48 h and longer, whereas the placebo film dissolved in 15 min. In 0.9% NaCl medium, the film became more soluble, dissolving within 3–4 h. However, cisplatin release was still controlled by the existing complex in solution until chloride ions displaced it. While the film modified its dissolution with aging, CisPt release remained unaffected (90% released in 48 h).

Relapse Patterns and Tailored Treatment Strategies for Malignant Pleural Mesothelioma Recurrence after Multimodality Therapy

To date, there have been no established therapies for recurrent malignant pleural mesothelioma (MPM) after multimodality treatment. Aims of this retrospective study are to analyze the recurrence pattern, its treatment and to identify the predictors of best oncological outcomes for relapsed MPM, comparing extrapleural pneumonectomy (EPP) vs. pleurectomy/decortication (PD). Study population: 94 patients with recurrence of MPM after multimodality treatment underwent macroscopic complete resection (52.1% with EPP and 47.9% with PD) between July 1994 and February 2020. Distant spread was the most frequent pattern of recurrence (71.3%), mostly in the EPP group, while the PD group showed a higher local-only failure rate. Post-recurrence treatment was administered in 86.2%, whereas best supportive care was administered in 13.8%. Median post-recurrence survival (PRS) was 12 months (EPP 14 vs. PD 8 months, p = 0.4338). At multivariate analysis, predictors of best PRS were epithelial histology (p = 0.026, HR 0.491, IC95% 0.263–0.916), local failure (p = 0.027, HR 0.707, IC95% 0.521–0.961), DFS ≥ 12 months (p = 0.006, HR 0.298, IC95% 0.137–0.812) and post-recurrence medical treatment (p = 0.046, HR 0.101, IC95% 0.897–0.936). The type of surgical intervention seems not to influence the PRS if patients are fit enough to face post-recurrence treatments. In patients with a prolonged disease-free interval, in the case of recurrence the most appropriate treatment seems to be the systemic medical therapy, even in the case of local-only relapse.

Outcomes of Conversion to Extrapleural Pneumonectomy From Pleurectomy/Decortication for Malignant Pleural Mesothelioma

In recent years, there has been a shift from extrapleural pneumonectomy (EPP) toward pleurectomy/decortication (P/D) as the preferred surgical technique. However, we occasionally encounter difficult cases wherein visceral pleurectomy requires conversion to EPP from P/D. We sought to clarify the preoperative risk factors and clinical outcomes associated with conversion to EPP. We compared and analyzed conversion to EPP and P/D between September 2012 and December 2019. Conversion to EPP was decided in case of diffuse tumor invasion to the pulmonary parenchyma or due to failure of decortication. Univariable regression analysis was performed to determine the association of preoperative variables with conversion to EPP. Survival was analyzed by the Kaplan-Meier method and log-rank test. Of the 181 patients who underwent intended P/D, 145 (80.1%) patients underwent P/D and 18 (9.9%) patients underwent conversion to EPP. The sum of 3-level pleural thickness (P < 0.001), maximum of 3-level pleural thickness (P = 0.006), and clinical T stage (P < 0.001) demonstrated association with conversion to EPP. Overall survival and progression-free survival were significantly worse in the conversion to EPP group (median overall survival, 29.2 months vs 57.0 months [P = 0.008]; median progression-free survival, 15.3 months vs 23.2 months [P = 0.005]. Our data show that approximately 1 of every 10 patients with P/D intention converted to EPP. Preoperative pleural thickness and clinical T stage may be risk factors associated with conversion to EPP. The survival rate of conversion to EPP was worse than that of P/D.

Three tumor markers for improved efficacy in the management of patients with malignant pleural mesothelioma

Background

Evaluation of tumor markers may facilitate follow-up of malignant pleural mesothelioma (MPM). We aimed was to evaluate the value of tumor markers for monitoring and predicting recurrence in patients with MPM.

Methods

In total, 152 patients who underwent curative-intent surgery after induction chemotherapy for MPM between July 2004 and December 2017 were retrospectively reviewed. Preoperative and postoperative (≤3 months after surgery) levels of soluble mesothelin-related peptide (SMRP), cytokeratin 19 fragment (Cyfra21-1), and tissue polypeptide antigen (TPA) and rates of recurrence and non-recurrence were evaluated. Factors associated with recurrence-free survival (RFS) were assessed using the Kaplan-Meier method and Cox proportional hazards model.

Results

Of the 152 patients, the positive rates of preoperative SMRP, Cyfra21-1, and TPA, levels were 26.7%, 8.6%, 9.6%, respectively; the respective postoperative levels were 4.0%, 6.3%, and 6.5%; the respective levels in patients with recurrence were 39.3%, 31.4%, 28.6%; the respective levels in patients with no recurrence were 3.7%, 0.0%, 3.8%. Nearly half (45.2%) of the patients with recurrence exhibited an increase in one or more tumor marker levels. Multivariate analysis revealed that the preoperative positive rates of one or more of the three tumor markers (hazard ratio: 1.8, 95% confidence interval: 1.1–2.8; P=0.02) were independent significant predictors of recurrence.

Conclusions

The positive rates of SMRP, Cyfra21-1, and TPA in recurrence-free patients were extremely low, with high specificity. Preoperative levels of SMRP, Cyfra21-1, and TPA, which identified patients with a high risk for recurrence, could improve management of patients with MPM.

Complications and Predictive Factors for Air Leak > 10 Days with Neoadjuvant Chemotherapy Followed by Pleurectomy/Decortication for Malignant Pleural Mesothelioma

BACKGROUND

A few studies have reported the incidence and clinical implications of complications after pleurectomy/decortication (P/D).

OBJECTIVE

The aim of this study was to assess the details of complications and predictive factors of particularly durable air leak with P/D.

METHODS

Data on 163 consecutive patients who underwent neoadjuvant chemotherapy (NAC) followed by P/D for malignant pleural mesothelioma between September 2012 and May 2020 at our institution were retrospectively analyzed. Postoperative complications and the significance of various preoperative risk factors for air leak > 10 days (AL10) to identify the group having a higher risk for particularly durable air leak were investigated. Risk factors for AL10 were sought using univariate and multivariate analyses.

RESULTS

Of 163 patients, 30- and 90-day mortality was 0.6% and 2.5%, respectively. Eighty-four (51.4%) patients experienced grade III or worse postoperative complications according to the Clavien-Dindo classification. The median duration of air leak was 7 postoperative days. AL10 occurred in 53 (32.5%) patients. Fifty-eight patients (35.6%) underwent pleurodesis and five patients (3.1%) underwent reoperation to control the air leak. On univariate analysis, performance status (PS; p = 0.003), prognostic nutritional index (p = 0.01), and pleural effusion (p = 0.04) were statistically significant risk factors for AL10, while on multivariate analysis, PS (odds ratio 4.0, 95% confidence interval 1.3-12.7; p = 0.02) remained the only variable predicted for AL10.

CONCLUSIONS

Recent postoperative mortality rates in NAC followed by P/D are quite acceptable. Approximately one in every three patients experienced AL10, and PS may be a risk factor associated with AL10.

Initial evaluation of nivolumab in patients with post-operative recurrence of malignant pleural mesothelioma

BACKGROUND

Limited options exist for treating post-recurrence patients with malignant pleural mesothelioma (MPM). This study aimed to evaluate the efficacy and feasibility of nivolumab in patients with post-operative recurrence of MPM in a real-world setting.

METHODS

This study included 35 patients with post-operative recurrence of MPM. Treatment consisted of 240-mg intravenous nivolumab administration every 2 weeks until progressive disease (PD) or serious adverse events (AEs). Additional post-treatment data were evaluated, including objective response rate (ORR), disease control rate (DCR), progression-free survival (PFS), post-treatment survival and AEs. Tumor response was assessed using the modified Response Evaluation Criteria in Solid Tumors. Survival analysis was performed using the Kaplan-Meier method. The feasibility analysis including AEs was performed with the National Cancer Institute Common Terminology Criteria for Adverse Events version 5.0.

RESULTS

Of the 35 patients who received nivolumab, median follow-up was 6 months. The median treatment duration was 3 months (range: 1-14 months), and median of 8 cycles (range: 2-32 cycles) was administered. Best overall responses were follows: 1 patient had complete response, 6 had partial response, 18 had stable disease and 8 had PD. The ORR was 20.0%, and the DCR was 77.1%. The median overall survival and PFS were 13.1 and 4.4 months, respectively. There were grade-3 AEs in four patients (11.4%). No grade-4 or -5 AEs were observed.

CONCLUSION

Nivolumab treatment in patients with post-operative recurrence of MPM seems safe and clinical efficacy.

Clinicopathological features of radiological early malignant pleural mesothelioma with no apparent tumor or pleural thickening

BACKGROUND

We occasionally encounter malignant pleural mesothelioma (MPM) of no apparent tumor or pleural thickening that is radiological early MPM. This study aimed to examine the clinicopathological outcomes of radiological early MPM.

METHODS

Patients with MPM treated with neoadjuvant chemotherapy and planned surgery at the time of diagnosis between July 2004 and December 2019 were retrospectively examined. Pretreatment maximal pleural thickness of all patients was measured on chest computed tomography. We extracted and investigated the patients who exhibited a lack of pleural thickening or visible tumor, which was defined as radiological early MPM. Survival was analyzed by the Kaplan-Meier method.

RESULTS

Of 296treated patients, 16 (5.4%) exhibited radiological early MPM. Fourteen (87.5%) of these patients underwent pleurectomy/decortication and 2 (12.5%) underwent extrapleural pneumonectomy. Pathological stage T1 disease was diagnosed in 14 (87.5%) patients; 2 (12.5%) exhibited pulmonary parenchymal invasion (pathological stage T2). Lymphatic invasion was detected in only 1 patient. Lymph node metastases and vascular invasion were not detected. Median follow-up was 42 months. Median progression-free survival and median overall survival were 40.7 and 56.1 months, respectively. The 3-year progression-free survival and overall survival rates were 84.8% and 83.6%, respectively.

CONCLUSIONS

Radiological early MPM occurs in approximately 1 of every 20 patients treated with neoadjuvant chemotherapy and surgery planned at the time of diagnosis in an experienced center. Radiological early MPM was associated with early pathological stage and long-term survival.