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

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.

Validation of Inflammatory Prognostic Biomarkers in Pleural Mesothelioma

Evoked from asbestos-induced inflammation, pleural mesothelioma represents a fatal diagnosis. Therapy ranges from nihilism to aggressive multimodality regimens. However, it is still unclear who ultimately benefits from which treatment. We aimed to re-challenge inflammatory-related biomarkers' prognostic value in times of modern immune-oncology and lung-sparing surgery. The biomarkers (leukocytes, hemoglobin, platelets, neutrophils, lymphocytes, monocytes, neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR), platelet-lymphocyte ratio (PLR), C-reactive protein (CRP)) and clinical characteristics (age, sex, histology, therapy) of 98 PM patients were correlated to overall survival (OS). The median OS was 19.4 months. Significant OS advantages (Log-Rank) were observed in multimodal treatment vs. others (26.1 vs. 7.2 months, p < 0.001), surgery (pleurectomy/decortication) vs. no surgery (25.5 vs. 3.8 months, p < 0.001), a high hemoglobin level (cut-off 12 g/dL, 15 vs. 24.2 months, p = 0.021), a low platelet count (cut-off 280 G/L, 26.1 vs. 11.7 months, p < 0.001), and a low PLR (cut-off 194.5, 25.5 vs. 12.3 months, p = 0.023). Histology (epithelioid vs. non-epithelioid, p = 0.002), surgery (p = 0.004), CRP (cut-off 1 mg/dL, p = 0.039), and platelets (p = 0.025) were identified as independent prognostic variables for this cohort in multivariate analysis (Cox regression, covariates: age, sex, histology, stage, CRP, platelets). Our data verified the previously shown prognostic role of systemic inflammatory parameters in patients treated with lung-sparing surgery within multimodality therapy.

Evaluation of Detector Position and Light Fluence Distribution Using an Infrared Navigation System during Pleural Photodynamic Therapy†

Photodynamic therapy (PDT) has been used to treat malignant pleural mesothelioma. Current practice involves delivering light to a prescribed light fluence with a point source, monitored by eight isotropic detectors inside the pleural cavity. An infrared (IR) navigation system was used to track the location of the point source throughout the treatment. The recorded data were used to reconstruct the pleural cavity and calculate the light fluence to the whole cavity. An automatic algorithm was developed recently to calculate the detector positions based on recorded data within an hour. This algorithm was applied to patient case studies and the calculated results were compared to the measured positions, with an average difference of 2.5 cm. Calculated light fluence at calculated positions were compared to measured values. The differences between the calculated and measured light fluence were within 14% for all cases, with a fixed scattering constant and a dual correction method. Fluence-surface histogram (FSH) was calculated for photofrin-mediated PDT to be able to cover 80% of pleural surface area to 50 J cm-2 (83.3% of 60 J cm-2 ). The study demonstrates that it will be possible to eliminate the manual measurement of the detector positions, reducing the patient's time under anesthesia.

Current Management and Future Perspective in Pleural Mesothelioma

Pleural mesothelioma is an aggressive malignancy arising from pleural mesothelial cell lining, predominantly associated with prior exposure to asbestos. The ban on asbestos use has led to its lower incidence in many countries, but globally the disease burden is expected to rise. Therefore, well-planned research is needed to develop more effective, tolerable and affordable drugs. The development of novel treatment has been too slow, with only two regimens of systemic therapy with robust phase 3 data approved formally to date. The treatment scenario for resectable disease remains controversial. However, recent developments in the understanding of disease and clinical trials have been encouraging, and may add better treatment options in the coming years. In this review, we discuss the current treatment options for pleural mesothelioma and shed light on some recent studies and ongoing trials.

Epidemiology and Clinical Aspects of Malignant Pleural Mesothelioma

Mesothelioma is a cancer predominantly of the pleural cavity. There is a clear association of exposure to asbestos with a dose dependent risk of mesothelioma. The incidence of mesothelioma in different countries reflect the historical patterns of commercial asbestos utilisation in the last century and predominant occupational exposures mean that mesothelioma is mostly seen in males. Modern imaging techniques and advances in immunohistochemical staining have contributed to an improved diagnosis of mesothelioma. There have also been recent advances in immune checkpoint inhibition, however, mesothelioma remains very challenging to manage, especially considering its limited response to conventional systemic anticancer therapy and that no cure exists. Palliative interventions and support remain paramount with a median survival of 9-12 months after diagnosis. The epidemiology and diagnosis of mesothelioma has been debated over previous decades, due to a number of factors, such as the long latent period following asbestos exposure and disease occurrence, the different potencies of the various forms of asbestos used commercially, the occurrence of mesothelioma in the peritoneal cavity and its heterogeneous pathological and cytological appearances. This review will describe the contemporary knowledge on the epidemiology of mesothelioma and provide an overview of the best clinical practice including diagnostic approaches and management.

A Case of Pulmonary Embolism with Sarcomatoid Malignant Pleural Mesothelioma with Long-Term Pleural Effusion

Background

Malignant pleural mesothelioma (MPM) is a highly aggressive tumor that originates from pleural mesothelial cells. In recent years, with the development of asbestos-related industries and the increase in air pollution, its incidence has been increased. The incidence of pulmonary embolism combined with sarcomatoid MPM is very low and the prognosis is extremely poor. We here report a case of a patient with long term of pleural effusion and finally diagnosed as pulmonary embolism with sarcomatoid MPM.

Case

A 75-year-old male with a 30-year history of asbestos exposure was admitted to our hospital due to chest pain and difficulty in breathing after exercise. Radiologic examination revealed pleural effusion, computed tomography pulmonary angiography (CTPA) suggests pulmonary embolism, and we consider pleural effusion caused by pulmonary embolism. After anticoagulant therapy for pulmonary embolism and pleural puncture to reduce pleural effusion, the patient's symptoms improved. However, after that, the patient was still admitted to the hospital several times because of recurrent chest pain and dyspnea symptoms, and radiologic examination always showed unexplained pleural effusion. Finally, pathological and immunohistochemical examinations of the pleural biopsy specimens were performed, and the diagnosis was confirmed as sarcomatoid MPM.

Conclusion

In summary, sarcomatoid MPM with pulmonary embolism is relatively rare, and the prognosis is poor. Clinicians need to be alert to its occurrence. When the first diagnosis is confirmed and the effect of targeted treatment is still not good, the possibility of other diseases should be considered. In clinical practice, pleural biopsy guided by PET-CT is a good choice for patients with sarcomatoid MPM who cannot tolerate open pleural biopsies or thoracoscopy. And patients should undergo pleural morphology and immunohistochemistry as soon as possible, which are helpful for timely diagnosis.

Surgical Management and Reconstruction of Diaphragm, Pericardium and Chest Wall in Mesothelioma Surgery: A Review

Mesothelioma is an aggressive disease arising from parietal pleura. Surgery is a valuable option in the frame of a multimodality treatment. Several surgical approaches have been standardized with the aim of a macroscopic complete resection; these often require homolateral diaphragm and pericardial resection and reconstruction. Extrapleural pneumonectomy (EPP) and extended pleurectomy decortication (EPD) have been recognized as radical surgical procedures. Nevertheless, both operations are technically challenging and associated with a significant rate of peri-operative morbidity and non-negligible mortality. The diaphragmatic and pericardial reconstruction technique is mandatory to avoid respiratory impairment and to reduce post-operative complications like gastric and cardiac herniation. Moreover, in the case of localized chest wall recurrence, surgery might be considered a valuable therapeutical option for highly selected and fit patients. All the technical aspects of the resection and reconstruction of the diaphragm, pericardium, and chest wall are described as well as the possible use of new minimally invasive techniques. In addition, the choice of different prosthetic materials, considering the most recent innovations in the field, are discussed.

Extended pleurectomy decortication: the current role

Extended pleurectomy/decortication (EPD) has been formally defined but there remain technical areas of debate between practitioners. This is partly attributable to the relative rarity of this operation which is largely confined to a small number of specialist centres. Nevertheless, there is a widespread acceptance that extended pleurectomy/decortication (P/D) is a realistic and favourable alternative to extrapleural pneumonectomy. There may, however, remain a small number of clinical cases where this more extensive operation may be indicated. Preservation of the lung has widened the selection criteria for this form of radical mesothelioma surgery but there remain important factors to consider when offering extended P/D. In many patients with poorer prognostic factors the less radical operation of video assisted partial pleurectomy may be preferable. However, a randomized trial showed no survival benefit for this operation over simple talc pleurodesis. The future for P/D may also lie in the outcome of the MARS2 randomized controlled trial which will report in the next few years. Meanwhile there is a clinical and ethical dilemma when asked to perform this operation outside of the context of a clinical trial in the face of the lack of high grade evidence. The role of P/D is in one respect expanding but this may be short lived pending the findings of its assessment against non-surgical treatment.

Radical multimodality therapy for malignant pleural mesothelioma

BACKGROUND

Malignant pleural mesothelioma is an almost always fatal tumour, for which palliative platinum-based chemotherapy is currently the standard treatment. Multimodal therapeutic strategies incorporating surgery, radiation therapy or photodynamic therapy and chemotherapy have been recommended for selected patients but there is no consensus about their effectiveness.

OBJECTIVES

To assess the benefits and harms of radical multimodal treatment options (including radical surgery ± radical radiotherapy ± photodynamic therapy ± systemic therapy) compared to each other or to palliative treatments, for people with malignant pleural mesothelioma.

SEARCH METHODS

We reviewed data from the Cochrane Lung Cancer group's Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE and Embase. We also checked reference lists of primary original studies, review articles and relevant conference proceedings manually for further related articles up to 21 March 2017.

SELECTION CRITERIA

We included parallel-group randomised controlled trials of multimodal therapy for people with malignant pleural mesothelioma (stages I, II or III) that measured at least one of the following endpoints: overall survival, health-related health-related quality of life, adverse events or progression-free survival. We considered studies regardless of language or publication status.

DATA COLLECTION AND ANALYSIS

Two review authors independently extracted relevant information on participant characteristics, interventions, study outcomes, and data on the outcomes for this review, as well as information on the design and methodology of the studies. Two review authors assessed the risk of bias in the included trials using pre-defined 'Risk of bias' domains. We assessed the methodological quality using GRADE.

MAIN RESULTS

We conducted this review in accordance with the published Cochrane protocol. Two randomised clinical trials with 104 participants fulfilled our inclusion criteria. Both trials were at high risk of bias (for outcomes other than overall survival), and we rated the evidence as moderate quality for overall survival and low quality for all other outcomes. One trial compared combined extrapleural pneumonectomy (EPP) plus neoadjuvant platinum-based chemotherapy plus postoperative high-dose hemithoracic radiotherapy with combined EPP plus platinum-based chemotherapy. The other trial compared EPP plus postoperative hemithoracic radiotherapy with standard (non-radical) therapy alone following platinum-based chemotherapy (patients in the standard therapy arm received continued oncological management according to local policy, which could include further chemotherapy or palliative radiotherapy).For the first trial, median overall survival calculated from registration was 20.8 months (95% confidence interval (CI) 14.4 to 27.8) in the no-radiotherapy group and 19.3 months (95% CI 11.5 to 21.8) in the radiotherapy group. For the second trial, median overall survival was 14.4 months (95% CI 5.3 to 18.7) for patients allocated to EPP and 19.5 months (95% CI 13.4 to time not yet reached) for patients randomised to standard non-radical therapy. In the second trial, 12 serious adverse events were reported during the study period: ten in the EPP group and two in the non-radical therapy group. Overall health-related quality of life scores were not different between the two arms in either study. We could not perform a meta-analysis of the two included trials due to clinical heterogeneity. We also identified three ongoing trials evaluating the topic of our review.

AUTHORS' CONCLUSIONS

The overall strength of the evidence gathered in this review is low and there is a lack of available evidence to support the use of radical multimodality therapy in routine clinical practice (particularly as one trial suggests greater harm). Given the added cost of multimodality treatment and the possible increase in risk of adverse effects, the lack of evidence of their effectiveness probably means that these interventions should currently be limited to clinical trials alone.

Surgery for malignant pleural mesothelioma: an international guidelines review

Currently there is no universally accepted surgical therapy for malignant pleural mesothelioma (MPM). The goal of surgery in this dismal disease is a macroscopic complete resection (MCR) and there are two types of intervention with a curative intent. At one side, there is the extrapleural pneumonectomy (EPP) which consists in an en-bloc resection of the lung, pleura, pericardium and diaphragm and at the other side, there is pleurectomy/decortication (P/D) a lung-sparing surgery. Initially, EPP was considered the only surgical option with a curative aim, but during the decades P/D have acquired a role of increasing importance in MPM therapy. Several randomized prospective trials are required to establish the best strategy in the treatment of pleural mesothelioma. Although which is the best surgical option remains unclear, the International Mesothelioma Interest Group (IMIG), recently have stated that the type of surgery depends on clinical factors and on individual surgical judgment and expertise. Moreover, according to the current evidence, the surgery should be performed in high-volume centres within multimodality protocols. The aim of this study is to examine the currently available international guidelines in the surgical diagnosis and treatment of MPM.

The role of intracavitary therapies in the treatment of malignant pleural mesothelioma

Surgery is one of the steps of multimodality approach for the treatment of MPM. Due to anatomical features, microscopically radical (R0) resection is never possible and a Macroscopic Complete Resection (R1) is considered the target for mesothelioma surgeons. Recently, intracavitary therapies have been described with the aim of extending the loco-regional effect of surgery. Different agents might be administered intrapleurally: chemotherapy drugs are the most widely used, but also photodynamic therapy (PDT) showed to lead to satisfactory long-term outcomes; furthermore, immunotherapies and gene therapies have been also reported. Despite promising results, no high-quality evidences are currently available and controlled randomized trials are required to establish the exact role of intracavitary therapies and to standardize the technique.

Diaphragm and lung-preserving surgery with hyperthermic chemotherapy for malignant pleural mesothelioma: A 10-year experience

BACKGROUND

The best surgical treatment for malignant pleural mesothelioma is still under a debate, but recent evidence points toward a less-invasive approach to reduce morbidity and mortality. We reported our 10-year experience of a limited surgical approach associated with hyperthermic intrathoracic chemotherapy (HITHOC).

MATERIAL AND METHODS

Between 2005 and 2014, patients with epithelioid or biphasic malignant pleural mesothelioma were treated with lung-diaphragm-pericardium-sparing pleurectomy associated with double-drug HITHOC; at least 3 cycles of adjuvant chemotherapy were then administered. The primary outcome examined was the feasibility of the procedure, whereas secondary outcomes were overall survival and disease-free interval.

RESULTS

Among 49 patients, 41 were male. Median age was 68 years (35-76 years). Histology was epithelioid in 43 cases. Pathologic stage I, II, III, and IV occurred in 12, 14, 20, and 3 cases, respectively. No intraoperative complications or postoperative mortality occurred, whereas morbidity rate was 46.9%. Median hospital stay was 8 days (5-45 days). Actuarial median overall survival was 22 months and a 1-, 2-, and 5-year survival accounted for 79.6%, 45.7%, and 9.9%, respectively. Disease-free survival after surgery was 62%, 37.5%, and 18.5% at 1, 2, and 5 years, respectively. Risk factors analysis for overall survival confirmed a significant role for early stages, epithelioid histology, and fibrinogen serum levels.

CONCLUSIONS

Cytoreductive surgery associated with HITHOC and adjuvant chemotherapy appears feasible and safe, with no mortality and low morbidity. Preserving lung and diaphragmatic function might warrant an acceptable long-term outcome.

A nuanced view of extrapleural pneumonectomy for malignant pleural mesothelioma

Multimodality treatment including macroscopic complete resection (MCR) is currently the most effective therapy for patients with malignant pleural mesothelioma (MPM). However, the allocation to one of the possible combinations has to be discussed individually since various factors influence the decision making process. In the past years, relevant new information about the disease and the outcome of different treatment modalities have been generated, which allows a more individual allocation to the best treatment. For many years extrapleural pneumonectomy (EPP)-the most aggressive procedure to achieve a MCR-was the first choice in combination with adjuvant or neo-adjuvant chemotherapy and radiation therapy for all patients except those with minimal disease. However, mortality and morbidity of an EPP and the fact, that even with the most radical procedure only MCR and not a complete resection can be achieved, led to shift towards pleurectomy/decortication in most of the centers. But also today, EPP is still a valuable option in selected cases and the entire treatment concept requires a nuanced view, which will be discussed in this review.

Clinical-pharmacogenetic models for personalized cancer treatment: application to malignant mesothelioma

Large interindividual differences in treatment outcome are observed in cancer patients undergoing chemotherapy. Our aim was to develop and validate clinical-pharmacogenetic prediction models of gemcitabine/cisplatin or pemetrexed/cisplatin treatment outcome and develop an algorithm for genotype-based treatment recommendations in malignant mesothelioma (MM). We genotyped 189 MM patients for polymorphisms in gemcitabine, pemetrexed and cisplatin metabolism, transport and drug target genes and DNA repair pathways. To build respective clinical-pharmacogenetic models, pharmacogenetic scores were assigned by rounding regression coefficients. Gemcitabine/cisplatin model was based on training group of 71 patients and included CRP, histological type, performance status, RRM1 rs1042927, ERCC2 rs13181, ERCC1 rs3212986, and XRCC1 rs25487. Patients with higher score had shorter progression-free (PFS) and overall survival (P < 0.001). This model’s sensitivity was 0.615 and specificity 0.812. In independent validation group of 66 patients the sensitivity and specificity were 0.667 and 0.641, respectively. Pemetrexed/cisplatin model was based on 57 patients and included CRP, MTHFD1 rs2236225, and ABCC2 rs2273697. Patients with higher score had worse response and shorter PFS (P < 0.001). This model’s sensitivity was 0.750 and specificity 0.607. In independent validation group of 20 patients the sensitivity and specificity were 0.889 and 0.500, respectively. The proposed algorithm based on these models could enable the choice of the most effective chemotherapy for 85.5% of patients and lead to improved treatment outcome in MM.

Is less also better? A single-institution experience on treatment of early stage Malignant Pleural Mesothelioma

OBJECTIVES

No clear evidence of which surgical procedure should be performed for early stage mesothelioma is available to date. We analyzed our 10-year experience in the treatment of early stage mesothelioma with surgery and Hyperthermic IntraTHOracic Chemotherapy.

METHODS

We retrospectively analyzed all cases of histologically proven epithelioid or biphasic IMIG stage I and II mesothelioma that we operated between 2005 and 2014. We performed an open pleurectomy and partial decortication of any visible lesion on the visceral pleura in all cases and both diaphragm and pericardium were always spared; Hyperthermic IntraTHOracic Chemotherapy was ran using Cisplatin 80 mg/m² and Doxorubicin 25 mg/m² at a target temperature of 42.5 °C for 60 min.

RESULTS

We operated on 26 patients (23 male and 3 female); epithelioid tumor was diagnosed in 23 cases. Twelve patients were in IMIG stage I and 14 in IMIG stage II; median overall survival for all patients, stage I and II were 35.6, 46 and 23 months respectively and disease free survival was 18, 18 and 16 months respectively. Our results for stage I were better than those reported in literature and were similar for stage II. We observe no 30- and 90- mortality and the rate of severe complication (all CTCAE stage 3) were 30%; the median postoperative stay was 7.5 days.

CONCLUSIONS

Our lung sparing approach for the treatment of pleural mesothelioma in early stages allows promising long term outcomes with a complete sparing of pulmonary and diaphragmatic function. Larger studies are needed to confirm our good results.

Chest wall resection for mesothelioma recurrence after surgery

Malignant pleural mesothelioma is an aggressive and usually fatal disease, and its optimal management is still under debate. Surgery for recurrent malignant mesothelioma has been reported rarely in highly selected cases. We report a case of chest wall resection for local recurrence of epithelioid mesothelioma 3 years after cytoreductive surgery. Our patient experienced a 6-month disease-free survival after redo surgery, with complete resolution of his chest pain and discomfort.