The case for routine cervical mediastinoscopy prior to radical surgery for malignant pleural mesothelioma

Does mediastinal lymph node involvement influence the surgical outcome in malign pleural mesothelioma?

BACKGROUND

This study examined the effect of metastatic mediastinal lymph node involvement on the prognosis of patients with malignant pleural mesothelioma (MPM) who underwent extrapleural pneumonectomy (EPP) or extended pleurectomy (E/P) and also to assess the effect of metastatic mediastinal lymph node involvement on the prognosis of patients with MPM in these group of patients.

METHODS

This retrospective study included 84 patients with MPM (66 men [78.6%] and 18 women [21.4%]) who underwent EPP (n = 44) or E/P (n = 40) at our institution between January 2001 and July 2019. Survival analyses were performed according to histopathology, nodal status, and surgical approach.

RESULTS

In the EPP group, patients with T2-N2 status had a significantly better mean survival (17 ± 2.1 months) than patients with T3-N2 (7.3 ± 1.6 months) or T4-N2 (3.2 ± 1.1 months) status (p = .001). In the E/P group, patients with T2-N2 status had a mean survival of 18 ± 1.1 months, while patients with T3-N2 and T4-N2 status had mean survival durations of 6.6 ± 1.6 and 4.8 ± 1.2 months, respectively (p = .159). In both treatment groups, the survival rates of patients with epithelial tumors were better than those of patients with non-epithelial tumors, independent of N status. None of the patients with N2 disease survived until 5 years postoperatively.

CONCLUSION

In summary, our results suggested that mediastinal lymph node metastasis negatively influenced the prognosis of patients with T3 MPM, regardless of treatment by EPP or E/P. Under these circumstances, preoperative cervical mediastinoscopy or endobronchial ultrasound-guided transbronchial needle aspiration may be considered for patients with high-stage MPM who are scheduled for surgery with curative intent. In our study, N2 status was spotted as a significant factor affecting survival, nevertheless its significance in survival of pleural mesothelioma patients should be analyzed in multi-centered studies.

Chinese expert consensus on the diagnosis and treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a malignant tumor originating from the pleura, and its incidence has been increasing in recent years. Due to the insidious onset and strong local invasiveness of MPM, most patients are diagnosed in the late stage and early screening and treatment for high-risk populations are crucial. The treatment of MPM mainly includes surgery, chemotherapy, and radiotherapy. Immunotherapy and electric field therapy have also been applied, leading to further improvements in patient survival. The Mesothelioma Group of the Yangtze River Delta Lung Cancer Cooperation Group (East China LUng caNcer Group, ECLUNG; Youth Committee) developed a national consensus on the clinical diagnosis and treatment of MPM based on existing clinical research evidence and the opinions of national experts. This consensus aims to promote the homogenization and standardization of MPM diagnosis and treatment in China, covering epidemiology, diagnosis, treatment, and follow-up.

ERS/ESTS/EACTS/ESTRO guidelines for the management of malignant pleural mesothelioma

The European Respiratory Society (ERS)/European Society of Thoracic Surgeons (ESTS)/European Association for Cardio-Thoracic Surgery (EACTS)/European Society for Radiotherapy and Oncology (ESTRO) task force brought together experts to update previous 2009 ERS/ESTS guidelines on management of malignant pleural mesothelioma (MPM), a rare cancer with globally poor outcome, after a systematic review of the 2009-2018 literature. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation approach. The evidence syntheses were discussed and recommendations formulated by this multidisciplinary group of experts. Diagnosis: pleural biopsies remain the gold standard to confirm the diagnosis, usually obtained by thoracoscopy but occasionally via image-guided percutaneous needle biopsy in cases of pleural symphysis or poor performance status. Pathology: standard staining procedures are insufficient in ∼10% of cases, justifying the use of specific markers, including BAP-1 and CDKN2A (p16) for the separation of atypical mesothelial proliferation from MPM. Staging: in the absence of a uniform, robust and validated staging system, we advise using the most recent 2016 8th TNM (tumour, node, metastasis) classification, with an algorithm for pretherapeutic assessment. Monitoring: patient's performance status, histological subtype and tumour volume are the main prognostic factors of clinical importance in routine MPM management. Other potential parameters should be recorded at baseline and reported in clinical trials. Treatment: (chemo)therapy has limited efficacy in MPM patients and only selected patients are candidates for radical surgery. New promising targeted therapies, immunotherapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasize that patients who are considered candidates for a multimodal approach, including radical surgery, should be treated as part of clinical trials in MPM-dedicated centres.

ERS/ESTS/EACTS/ESTRO guidelines for the management of malignant pleural mesothelioma

The European Respiratory Society (ERS)/European Society of Thoracic Surgeons (ESTS)/European Association for Cardio-Thoracic Surgery (EACTS)/European Society for Radiotherapy and Oncology (ESTRO) task force brought together experts to update previous 2009 ERS/ESTS guidelines on management of malignant pleural mesothelioma (MPM), a rare cancer with globally poor outcome, after a systematic review of the 2009-2018 literature. The evidence was appraised using the Grading of Recommendations, Assessment, Development and Evaluation approach. The evidence syntheses were discussed and recommendations formulated by this multidisciplinary group of experts. Diagnosis: pleural biopsies remain the gold standard to confirm the diagnosis, usually obtained by thoracoscopy but occasionally via image-guided percutaneous needle biopsy in cases of pleural symphysis or poor performance status. Pathology: standard staining procedures are insufficient in ∼10% of cases, justifying the use of specific markers, including BAP-1 and CDKN2A (p16) for the separation of atypical mesothelial proliferation from MPM. Staging: in the absence of a uniform, robust and validated staging system, we advise using the most recent 2016 8th TNM (tumour, node, metastasis) classification, with an algorithm for pre-therapeutic assessment. Monitoring: patient's performance status, histological subtype and tumour volume are the main prognostic factors of clinical importance in routine MPM management. Other potential parameters should be recorded at baseline and reported in clinical trials. Treatment: (chemo)therapy has limited efficacy in MPM patients and only selected patients are candidates for radical surgery. New promising targeted therapies, immunotherapies and strategies have been reviewed. Because of limited data on the best combination treatment, we emphasise that patients who are considered candidates for a multimodal approach, including radical surgery, should be treated as part of clinical trials in MPM-dedicated centres.

Mesothelioma: Scientific clues for prevention, diagnosis, and therapy

Mesothelioma affects mostly older individuals who have been occupationally exposed to asbestos. The global mesothelioma incidence and mortality rates are unknown, because data are not available from developing countries that continue to use large amounts of asbestos. The incidence rate of mesothelioma has decreased in Australia, the United States, and Western Europe, where the use of asbestos was banned or strictly regulated in the 1970s and 1980s, demonstrating the value of these preventive measures. However, in these same countries, the overall number of deaths from mesothelioma has not decreased as the size of the population and the percentage of old people have increased. Moreover, hotspots of mesothelioma may occur when carcinogenic fibers that are present in the environment are disturbed as rural areas are being developed. Novel immunohistochemical and molecular markers have improved the accuracy of diagnosis; however, about 14% (high-resource countries) to 50% (developing countries) of mesothelioma diagnoses are incorrect, resulting in inadequate treatment and complicating epidemiological studies. The discovery that germline BRCA1-asssociated protein 1 (BAP1) mutations cause mesothelioma and other cancers (BAP1 cancer syndrome) elucidated some of the key pathogenic mechanisms, and treatments targeting these molecular mechanisms and/or modulating the immune response are being tested. The role of surgery in pleural mesothelioma is controversial as it is difficult to predict who will benefit from aggressive management, even when local therapies are added to existing or novel systemic treatments. Treatment outcomes are improving, however, for peritoneal mesothelioma. Multidisciplinary international collaboration will be necessary to improve prevention, early detection, and treatment.

Endobronchial ultrasound-guided transbronchial needle aspiration mediastinal lymph node staging in malignant pleural mesothelioma

Background

Given poor survival of patients with malignant pleural mesothelioma (MPM) and extrapleural nodal metastasis, pre-operative mediastinal lymph node (LN) staging has been advocated. Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) may be a useful pre-operative adjunct in patients with MPM. This study aims to assess performance of EBUS-TBNA for mediastinal LN staging in MPM.

Methods

A retrospective chart review of patients with diagnosis of MPM referred to the mesothelioma program at a tertiary Canadian cancer center between January 1, 2012 and December 31, 2014 who received mediastinal LN staging with EBUS-TBNA.

Results

Forty-eight patients were included. Average age was 70 years (range, 48-84 years). Mesothelioma subtypes were as follows: epithelioid 34/48 (70.8%), sarcomatoid 4/48 (8.3%), biphasic 7/48 (14.6%) and other 3/48 (6.3%). Stage distribution was as follows: I 18.8%, II 10.4%, III 47.9%, and IV 22.9%. On average 3.4 LNs were sampled per patient (range, 1-5). The mean short axis of a sampled LN was 6.8±3.8 mm. Rapid on Site Evaluation (ROSE) was available in 75.0% (36/48) of the assessments. Prevalence of N2/N3 disease was 35.4% (17/48). EBUS-TBNA sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and diagnostic accuracy were: 16.7%, 100%, 100%, 68.8%, and 70.6%, respectively. EBUS-TBNA mediastinal LN staging prevented unnecessary surgery in 18.8% (9/48 patients) by detection of N2/N3 disease (8 patients) and metastatic secondary malignancy (1 patient). There were no EBUS-TBNA related complications.

Conclusions

EBUS-TBNA mediastinal LN staging may impact significantly management of patients with MPM by detecting mediastinal metastatic disease, therefore, preventing morbidity and mortality of surgical management.

MR Imaging of Pleural Neoplasms

The pleura may be affected by primary tumors or metastatic spread of intrathoracic or extrathoracic neoplasms. Primary pleural neoplasms represent ∼10% of all pleural tumors, and malignant lesions are more common than benign lesions. The most common primary tumors include malignant pleural mesothelioma and solitary fibrous tumor. Although pleural neoplasms may initially be evaluated with computed tomography (CT) and/or fluorodeoxyglucose positron emission tomography (PET)/CT, magnetic resonance (MR) imaging is complementary to these other imaging modalities for disease staging and evaluation of patients. In this article, we discuss the etiology, clinical presentation, and imaging of pleural neoplasms, with specific attention given to the role of MR imaging.

Malignant pleural mesothelioma: predictors and staging

Malignant pleural mesothelioma remains a rapidly fatal cancer with few effective therapies. Unusual anatomic features complicate determination of stage and prognosis for individual patients. Validation of staging criteria has been difficult given the rarity of the disease and the fact that only a minority of patients undergo surgical resection with pathological examination of their tumors. Thus, additional heuristic factors and algorithms have been taken into account by clinicians to estimate prognosis and inform discussion of appropriate management strategies or clinical research protocols with patients.

Management of Malignant Mesothelioma by Decortication and Adjunct Phototherapy

Malignant mesothelioma is a relatively rare tumor that originates in the pleural space and almost invariably results from exposure to asbestos. Between September 1989 and December 1999, 100 patients were managed with curative intent using a combination of full decortication, adjunct phototherapy after administration of hematoporphyrin derivative, and strip radiotherapy to any areas where adequate clearance was not obtained. The survival curve was compared to that of 17 matched patients treated by decortication alone. Median survival increased from 250 to 440 days in the combined treatment group.

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

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

The new case for cervical mediastinoscopy in selection for radical surgery for malignant pleural mesothelioma

OBJECTIVES

Selection criteria for radical surgery in malignant pleural mesothelioma (MPM) and related clinical trials remain controversial. The relative importance of nodal metastases and the need for pre-operative nodal staging are undetermined.

METHODS

From a prospective database, we identified 212 patients with non-sarcomatoid MPM (160 epithelioid and 52 biphasic). A total of 127 patients underwent extrapleural pneumonectoctomy (EPP) and 85 lung-sparing total pleurectomy (LSTP) with lymphadenectomy. We investigated the effect of nodal burden and distribution in survival by testing for differences between N0, N1 and N2 disease and constructing a theoretical model dividing the patients into four groups according to diseased nodes identified in the surgical specimen: Group 0, no nodal disease; Group CM, nodes accessible by cervical mediastinoscopy (CM): Stations 2, 3a, 4 and 7; Group EBUS/EUS, nodes accessible by endobronchial (EBUS) or endoscopic (EUS) ultrasound: Stations 2, 3a, 4 and 7-11. Group EM, extramediastinal nodes not accessible by CM or EBUS/EUS: Stations 5, 6, internal mammary, pericardial and diaphragmatic lymph nodes.

RESULTS

There was no difference in overall median survival between EPP and LSTP [15.6, SE 1.8, 95% confidence interval (CI) 12-19 months versus 13.4, SE 2.3, 95% CI 9-18 months, P=0.41]. Patients with N0 disease (n=94) had the best prognosis: median survival was 19.6 months (SE 3, 95% CI 13.2-26) versus 12 months for the 19 patients with N1 (SE 1.5, 95% CI 9-15) and 13.6 months for 99 patients with N2 (SE 1.7, 95% CI 10-17), P=0.015. Subgroup analysis of patients with nodal metastases revealed no significant survival difference between group CM and group EBUS/EUS: achieving maximum theoretical diagnostic yield CM could detect 63 (54%) of patients with nodal disease and the median survival of this group was 13.6 months (SE 2, 95% CI 9.6-17.6). EBUS/EUS could detect an additional 30 cases (26%) with survival of 11.3 months (SE 1, 95% CI 9-13.6). The survival in group EM (25 cases, 21%, median survival 18.7 months, SE 6, 95% CI 7-30) was significantly better than groups CM or EBUS/EUS, P=0.002.

CONCLUSIONS

There is a strong case for routine CM as a method of prognostic staging in all patients undergoing radical surgery for MPM. The addition of EUS staging and the detection of nodal metastases inaccessible to mediastinoscopy had no prognostic benefit.

Multimodality Imaging Review of Malignant Pleural Mesothelioma Diagnosis and Staging

Early diagnosis and accurate disease staging in patients with malignant pleural mesothelioma (MPM) are essential in classifying such patients into prognostic subgroups to allow delivery of stage-specific therapies. This review addresses the current status of multimodality imaging in the diagnosis and staging of MPM. Clinical, research, and future directions in computed tomography (CT), magnetic resonance imaging, and PET/CT diagnosis and staging of MPM are discussed, including the use of novel PET probes. The article concludes with important take-home messages summarized as the pearls and pitfalls of each diagnostic modality in the diagnosis and staging of patients with MPM.

Expert opinions of the first italian consensus conference on the management of malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a very important public health issue. A large amount of data indicates a relationship between mesothelioma and asbestos exposure. The incidence has both considerably and constantly increased over the past 2 decades in the industrialized countries and is expected to peak in 2010-2020. In Italy, a standardized-rate incidence in 2002 among men was 2.98 per 100,000 and 0.98 per 100,000 among women, with wide differences from one region to another. Stage diagnosis and definition may be difficult. Management of patients with MPM remains complex, so an optimal treatment strategy has not yet been clearly defined. The First Italian Consensus Conference on Malignant Pleural Mesothelioma was held Bologna (Italy) in May 20, 2008. The Consensus Conference was given the patronage of the Italian scientific societies AIOM, AIRO, AIPO, SIC, SICO, SICT, SIAPEC-IAP, AIOT, GOAM, and GIME. This Consensus did not answer all of the unresolved questions in MPM management, but the Expert Opinions have nonetheless provided recommendations, presented in this report, on MPM management for clinicians and patients.

Surgical therapy of mesothelioma

The treatment of malignant pleural mesothelioma is controversial, particularly regarding the role of surgery. Though well accepted as a diagnostic modality, surgery is also frequently used to establish stage, provide palliation, and perhaps most controversially, to offer cytoreduction with the putative goal of delaying tumor progression and prolonging survival. Pleurectomy/decortication (PD) can achieve macroscopic complete resection; however, the ability to deliver effective postoperative radiation treatment is limited because of the risk of lung toxicity. Accordingly, it has been associated with higher rates of local recurrence compared to extrapleural pneumonectomy (EPP). Extrapleural pneumonectomy generally offers a more complete cytoreduction compared to PD but at the cost of increased morbidity and mortality. Adjuvant hemithoracic radiation is feasible following EPP and in most series local recurrence rates are lower after EPP than PD. There are no convincing data, however, to show that one procedure is superior to the other in terms of survival. Furthermore, no randomized data currently exist that demonstrate a survival benefit to any form of surgical cytoreduction over systemic treatment and supportive care. If cytoreductive surgery does have a beneficial effect on long-term survival, it will most likely be realized in patients with epithelioid tumors without nodal metastases.

Surgical assessment of malignant pleural mesothelioma: have we reached a critical stage?

OBJECTIVE

The International Mesothelioma Interest Group (IMIG) classification is the most widely used staging system but is based on post-resectional parameters. We aimed to test the association between clinical and pathological staging and to identify possible discrepancies.

METHODS

We identified 164 consecutive patients (144 males and 20 females, with mean age 58 years) who underwent radical surgery (114 extrapleural pneumonectomy; 50 radical pleurectomy/decortication) for malignant pleural mesothelioma (MPM). The patients were clinically staged with CT + or - MRI (CT, computed tomography; MRI, magnetic resonance imaging).

RESULTS

Clinical T (cT) stage proved to be the same as pathological T (pT) stage in 44%; understaged in 46% and overstaged in 10%. Clinical N (cN) stage proved to be the same as pathological N (pN) stage in 56%; understaged in 31% and overstaged in 13%. Disease-free interval (DFI) was associated with cT stage (median DFI 29 months, SE 13, 95% CI 3-54 months for cT1; median 5, SE 3, 95% CI 3-6 months for cT4, p=0.02) but not clinical N stage (median DFI 12 months, SE 1, 95% CI 9-15 months for cN0; median DFI 11 months, SE 0.3, 95% CI 10-12 months for cN2, p=0.5) and was associated with both pT (median DFI 31 months, SE 17, 95% CI 0-64 months for pT1; median DFI 8 months, SE1, 95% CI 6-11 months for pT4, p=0.03) and pN stage (median DFI 14 months, SE 3, 95% CI 9-20 months for pN0; median DFI 10 months, SE 1, 95% CI 8-13 months for pN2, p=0.02). Overall survival was associated with cT stage (median survival 25 months, SE 3, 95% CI 20-30 months for cT1; median survival 11 months, SE 3, 95% CI 10-11 months for cT4, p=0.01) but not cN stage (median survival 15 months, SE 2, 95% CI 11-19 months for cN0; median survival 15 months, SE 2, 95% CI 12-19 months for cN2, p=0.49) and pN stage (median survival 22 months, SE 3, 95% CI 19-27 months for pN0; median survival 14 months, SE 1, 95% CI 12-17 months for pN2, p=0.01) but not pT stage (median survival 27 months, SE 4, 95% CI 19-35 months for pT1; median survival 12 months, SE 2, 95% CI 9-15 months for pT4, p=0.06). Pathological IMIG stage was associated with DFI and overall survival; however, preoperative IMIG stage was less useful.

CONCLUSIONS

There are deficiencies in the current staging system for MPM and discrepancies between clinical and pathological systems. Future improvements are needed in clinical descriptors of nodal status and pathological descriptors of T stage. Subsequent IMIG stage grouping also needs revision.

Unusual features of malignant pleural mesothelioma metastatic to the mediastinal lymph nodes

Malignant pleural mesothelioma (MPM) is a rare cancer that metastasizes to mediastinal lymph nodes (MLNs). The diagnosis of MPM metastatic to MLNs may not be straightforward. We describe 3 cases to highlight unusual entities of MPM metastatic to MLNs as follows. One patient with a history of T3N1M0, poorly differentiated esophageal adenocarcinoma and malignant melanoma presented with shortness of breath, mediastinal lymphadenopathy, and pleural effusion; metastatic disease was clinically suspected. Unexpectedly, immunohistochemical studies supported the diagnosis of MPM metastatic to the MLN on biopsy. In another case, mesothelial cell inclusions were initially diagnosed based on the light microscopy, immunohistochemistry, and lack of pleural thickening on computed tomography studies. Subsequent fine needle aspiration of an enlarged cervical lymph node found an atypical mesothelial proliferation, and metastatic mesothelioma was strongly suspected. Video-assisted thoracoscopic examination showed small visceral nodules, and pleural biopsy was diagnosed as malignant epithelioid mesothelioma. The mediastinal and cervical lymph node biopsies were reinterpreted as positive for MPM. In the last case, MLN biopsy showed a malignant epithelioid cell proliferation. Calretinin, CK5/6, WT-1, D2-40, p63, and CD5 were immunohistochemically detected in the tumor but epithelial markers and TTF-1 were negative. Metastatic mesothelioma was considered based on immunohistochemistry and computerized tomography finding of pleural thickening even though p63 and CD5 positivity were unusual. In summary, MPM may present as mediastinal lymphadenopathy with metastases or it may be a concurrent neoplasm with other malignancies or shows an unusual immunohistochemical staining pattern. Caution should be used when diagnosing mesothelial cell inclusions in MLNs.

Malignant mesothelioma 2008

PURPOSE OF REVIEW

Mesothelioma is an aggressive malignancy of the pleura with poor survival. There will be approximately 3000 cases of mesothelioma in the United States annually. Multimodality treatment including neoadjuvant chemotherapy in selected individuals followed by extrapleural pneumonectomy and radiation has been studied in recent trials for its effects on disease free and overall survival This review provides a general overview of malignant mesothelioma with a summary of the most significant articles from within the past year as well as from the past.

RECENT FINDINGS

Areas of recent interest include the evaluation of osteopontin and mesothelin as new tumor markers for mesothelioma. New phase III trials have been performed to evaluate the use of combined chemotherapy regimens.

SUMMARY

Malignant mesothelioma is a very difficult malignancy to treat. Patients with the disease usually have an occupational asbestos exposure, and in some, viral exposure with SV40. There have been many historical treatments including combinations of local control with surgery and radiation as well as attempts to prevent systemic failure with chemotherapy. Novel therapies including intrapleural chemotherapy, photodynamic therapy and hyperthermic perfusion have also been used with some success. Finally there are several attempts at immunomodulating and targeted treatments, which are in phase I/II trials.

Impact of lymph node metastasis on outcome after extrapleural pneumonectomy for malignant pleural mesothelioma

OBJECTIVES

Extrapleural pneumonectomy is a therapeutic option for selected patients with malignant pleural mesothelioma. The impact of lymph node metastasis on the site of recurrence and the role of mediastinoscopy in the selection of patients for extrapleural pneumonectomy, however, remain unclear.

METHODS

We reviewed 50 consecutive patients undergoing extrapleural pneumonectomy for malignant pleural mesothelioma in our institution between January 1993 and March 2005.

RESULTS

The median survival was 11 months, with a 3-year survival of 24%. Survival was significantly worse for patients with N2 disease than for those with no lymph node metastasis (median survival 10 months vs 29 months, respectively, P = .005). Patient sex, histologic cell type, stage, and N2 disease, but not mediastinoscopy, had significant impacts on survival according to univariate analysis. In a multivariate analysis, however, only the presence of N2 disease remained a significant predictor of poor outcome. The proportion of patients with N2 disease and the long-term survival was similar regardless of whether preoperative mediastinoscopy yielded a negative result. The initial site of recurrence was determined in 28 patients (locoregional in 10 and distant in 18). The presence of N2 disease had no impact on the site of recurrence. Adjuvant hemithoracic radiation therapy, however, significantly decreased the risk of locoregional recurrence.

CONCLUSIONS

The presence of N2 disease negatively affects the prognosis of patients with malignant pleural mesothelioma. Mediastinoscopy, however, seems to have a limited role in patient selection for extrapleural pneumonectomy. Adjuvant hemithoracic radiation therapy but not N2 disease affects the risk of locoregional recurrence.

Intraoperative localization of lymph node metastases with a replication-competent herpes simplex virus

OBJECTIVES

Lymph node status is the most important prognostic factor determining recurrence and survival in patients with mesothelioma and other thoracic malignancies. Accurate localization of lymph node metastases is therefore necessary to improve selection of resectable and curable patients for surgical intervention. This study investigates the potential to identify lymph node metastases intraoperatively by using herpes-guided cancer cell-specific expression of green fluorescent protein.

METHODS

After infection with NV1066, a herpes simplex virus carrying green fluorescent protein transgene, human mesothelioma cancer cell lines were assessed for cancer cell-specific infection, green fluorescent protein expression, viral replication, and cytotoxicity. Murine models of lymphatic metastasis were established by means of surgical implantation of cancer cells into the preauricular (drainage to cervical lymph nodes) and pleural (mediastinal and retroperitoneal lymph nodes) spaces of athymic mice. Fluorescent thoracoscopy, laparoscopy, and stereomicroscopy were used to localize lymph node metastases that were confirmed by means of immunohistochemistry.

RESULTS

In vitro NV1066 infected, replicated (5- to 17,000-fold), and expressed green fluorescent protein in all cancer cells, even when infected at a low ratio of one viral plaque-forming unit per 100 tumor cells. In vivo NV1066 injected into primary tumors was able to locate and infect lymph node metastases producing green fluorescent protein that was visualized by means of fluorescent imaging. Histology confirmed lymphatic metastases, and immunohistochemistry confirmed viral presence in regions that expressed green fluorescent protein.

CONCLUSIONS

Herpes virus-guided cancer cell-specific production of green fluorescent protein can facilitate accurate localization of lymph node metastases. Fluorescent filters that detect green fluorescent protein can be incorporated into operative scopes to precisely localize and biopsy lymph node metastases.

Management of Malignant Pleural Mesothelioma

Malignant mesothelioma is increasing in incidence globally and has no known cure. Its unique clinical feature of local infiltration along tissue planes makes it a difficult neoplasm to manage. There have been few randomized controlled trials regarding treatment options, although these have increased in recent years, and results are eagerly awaited. This article summarizes important advances in the management of mesothelioma, especially diagnostic and therapeutic aspects.

The pattern of lymph node involvement influences outcome after extrapleural pneumonectomy for malignant mesothelioma

OBJECTIVE

We sought to examine the distribution and prognostic implications of nodal metastasis in patients undergoing extrapleural pneumonectomy for malignant mesothelioma in a specialist center.

METHODS

We have examined the lymphadenectomy specimens from 92 consecutive cases of malignant mesothelioma undergoing extrapleural pneumonectomy from September 1999 through February 2005 inclusive. Nodal stations (Naruke) were assigned to all nodes, and patients were staged according to the current International Union Against Cancer system. The status and number of nodes in each station were recorded, and results were correlated with the results of preoperative mediastinoscopic findings (n = 30) and survival.

RESULTS

The nodal distribution was 48 N0, 9 N1, and 35 N2. Single and multistation nodal involvement was present in 20 and 24 cases, respectively. Among the patients undergoing mediastinoscopy, N2 disease after extrapleural pneumonectomy occurred in 10 (33%). Skip N2 metastasis was present in 10 (42%) cases. Positive N2 nodes inaccessible by mediastinoscopy were present in 17 (49%) cases. N2 metastasis was associated with reduced survival (P = .02), but there was no difference between N1 and N2 cases (P = .4). The number of positive nodes correlated with survival (P = .001), although the number of involved stations and their anatomic location did not. There was no difference in survival between skip N2 cases and either other N2 or N1 cases.

CONCLUSIONS

The classical anatomic location is not as important as the scatter of nodal involvement. Every effort should be made to obtain biopsy specimens from as many stations as possible before undertaking extrapleural pneumonectomy for malignant mesothelioma.

A Median Sternotomy Approach to Right Extrapleural Pneumonectomy for Mesothelioma

Although pulmonary resections have been performed through median sternotomy, this approach for extrapleural pneumonectomy in the management of malignant pleural mesothelioma has not been described. We assessed the feasibility of a median sternotomy approach as an alternative to thoracotomy in right-sided resections. Over a 15-month period, this approach was attempted in 10 cases. In 7 of them, the entire procedure was completed without additional thoracotomy access. There were no postoperative deaths in this group. At median follow-up of 8 months, we have not encountered tumor progression in the scars.

The effect of extent of local resection on patterns of disease progression in malignant pleural mesothelioma

BACKGROUND

We sought to determine whether or not there are differences in disease progression after radical or nonradical (debulking) surgical procedures for malignant pleural mesothelioma.

METHODS

Over a 49-month period, 132 patients with malignant pleural mesothelioma underwent surgery. Fifty-three underwent extrapleural pneumonectomy and 79 underwent nonradical procedures. Time to evidence of clinical disease progression was recorded, as was the site(s) of that disease.

RESULTS

One-hundred nineteen patients were evaluable, of which 59% (22 radical; 48 nonradical) had disease progression. Overall 30-day mortality was 8.5% (7.5% radical; 9% nonradical). The median time to overall disease progression was considerably longer after extrapleural pneumonectomy than debulking surgery (319 days vs 197 days, p = 0.019), as was the time to local disease progression (631 days vs 218 days, p = 0.0018). There was no preponderance of earlier stage disease in the radical surgery group. There was a trend toward prolonged survival in those undergoing radical surgery, but no significant difference between the groups (497 days vs 324 days, p = 0.079). In those who had extrapleural pneumonectomy, time-to-disease progression significantly decreased with N2 disease compared with N0/1 involvement (197 days vs 358 days, p = 0.02).

CONCLUSIONS

Extrapleural pneumonectomy may be preferable to debulking surgery in malignant pleural mesothelioma to delay disease progression and give greater control of local disease. Involvement of N2 nodes is associated with accelerated disease progression and is therefore a contraindication to extrapleural pneumonectomy.