What Is the Role of Radiotherapy in Malignant Pleural Mesothelioma?

Objective.

A review of the evidence supporting the use of radiotherapy in patients with mesothelioma was performed.

Methods.

Relevant publications were searched for on Medline.

Results.

In a Medline search on radiotherapy and mesothelioma, 611 hits were obtained. A limited number of prospective phase II trials of radiotherapy as part of trimodality protocols for early disease and in the palliation of pain were found, along with three small randomized controlled trials of port-site prophylaxis.

Conclusion.

No randomized data exist to support the use of radiotherapy after radical surgery, although there are a large number of publications describing its use as an integral part of therapy, including seven phase II studies. One ongoing trial is randomizing patients to radiotherapy or not after extrapleural pneumonectomy. None of these studies provided any assessment of radiotherapy independent of the other modalities investigated, nor did any formally assess intensity-modulated radiotherapy. There have been several reports of excessive toxicity with this technique, and its use should be limited to phase I studies until the basis of this toxicity is better understood. Three trials have looked at port-site prophylaxis, one supporting its use and two showing no evidence of benefit. Two studies addressed pain control prospectively, one showing definite but short-lived benefits.

Implications.

Radiotherapy is widely used in treating mesothelioma with little supporting evidence. More randomized trials are required to justify this use in all three common settings for its use.     

The Evolving Role of Gemcitabine and Pemetrexed (Alimta®) in the Management of Patients with Malignant Mesothelioma

Malignant mesothelioma is a refractory malignancy. Treatment for unresectable disease may provide a palliative benefit, but survival duration is impacted only minimally, if at all. Several newer agents, including difluorodeoxycytidine (gemcitabine) and pemetrexed disodium (LY231514, Alimta®) appear to have activity against this neoplasm. Phase II data for combination regimens of gemcitabine and a platinum in mesothelioma patients have been encouraging. However, no phase III data are available to place these phase II results in true perspective. In phase I studies of a cisplatin/pemetrexed combination, objective responses occurred in several mesothelioma patients. This led to a phase II trial of pemetrexed alone in untreated mesothelioma patients and a randomized phase III trial of cisplatin alone versus pemetrexed/cisplatin. Phase II activity (15% partial response) was seen with single-agent pemetrexed. The phase III trial accrued over 450 patients. Primary analysis of the phase III data set has been completed and the results will be presented at the American Society of Clinical Oncology Meeting in May 2002.     

Progress in the Management of Early-Stage Non–Small Cell Lung Cancer in 2017

The landscape of care for early-stage non–small cell lung cancer continues to evolve. While some of the developments do not seem as dramatic as what has occurred in advanced disease in recent years, there is a continuous improvement in our ability to diagnose disease earlier and more accurately. We have an increased understanding of the diversity of early-stage disease and how to better tailor treatments to make them more tolerable without impacting efficacy. The International Association for the Study of Lung Cancer and the Journal of Thoracic Oncology publish this annual update to help readers keep pace with these important developments. Experts in the care of early-stage lung cancer patients have provided focused updates across multiple areas including screening, pathology, staging, surgical techniques and novel technologies, adjuvant therapy, radiotherapy, surveillance, disparities, and quality of life. The source for information includes large academic meetings, the published literature, or novel unpublished data from other international oncology assemblies.     

Utility of Integrated Computed Tomography—Positron Emission Tomography for Selection of Operable Malignant Pleural Mesothelioma

BackgroundMalignant pleural mesothelioma (MPM) is a primary malignancy characterized by local invasion of the pleura and metastasis. Despite advances in computed tomography (CT) and magnetic resonance imaging (MRI), accurately staging patients remains challenging. Recent studies have examined the use of integrated CT—positron emission tomography (PET) for staging patients.Materials and MethodsMayo Clinic databases were queried to identify cases with a histologic diagnosis of MPM from 2000 to 2006. Inclusion criteria were a diagnosis of MPM, an available CT scan, and an initial staging integrated CT-PET scan. A total of 35 patients were identified who met the inclusion criteria. Computed tomography and integrated CT-PET scans were reviewed by experienced radiologists. Laboratory parameters were reviewed. The Mayo Clinic tumor registry and Social Security database were queried for survival data in patients in which no follow-up was available.ResultsFindings on integrated CT-PET excluded 14 of 35 patients from surgical intervention. Extrapleural pneumonectomies (EPPs) were performed in 8 patients, and partial pleurectomies were performed in 2 patients. Upstaging from integrated CT-PET occurred in 70% of the patients when surgical pathology was available, 2 cases to an inoperable stage. Although not statistically significant, median survival was 20 months for patients undergoing an EPP and 12 months for patients excluded from surgical intervention by integrated CT-PET.ConclusionMalignant pleural mesothelioma is a difficult disease to accurately stage. The most common reason for upstaging in our series was an increase in T (tumor; tumor-node-metastasis staging system) disease. Our data suggest that integrated CT-PET is excellent for detecting nodal and distant metastases. However, the ability of this imaging modality to correctly stage locoregional disease is not superior to the combination of CT and MRI as reported in the literature.     

The Role of CD90 in the Differential Diagnosis of Pleural Malignant Mesothelioma,Pulmonary Carcinoma and Comparison with Calretının

Pleural Malignant Mesothelioma (MM) is a fatal disease that has been associated with asbestos exposure. Differential diagnosis between the pleural infiltration of pulmonary carcinomas and MM is rather difficult particularly for epitheloid type mesothelioma.We aimed to investigate the utility of CD90, a cancer stem cell marker, in the differential diagnosis of MM and lung carcinoma, its prognostic significance and compare its value with that of Calretinin. Ninety pathology specimens including MM (n:30), pulmonary adenocarcinoma (n:30) and pulmonary squamous cell carcinoma (n:30) were used in this study. Immunohistochemical comparision of CD 90 and Calretinin was made in all groups. Calretinin was positive in 20 cases with MM (64.5 %), and was negative in 10 (32.3 %). CD 90 was positive in 25 of these cases (80 %) and negative in 5 (16 %). On the other hand pulmonary adenocarcinomas and squamous cell carcinomas showed positivity with CD90, 63,6 % and 73 %, respectively. We think that CD 90 has no place in the differential diagnosis between mesothelioma and pulmonary carcinoma because of the low specificity in spite of the high sensitivity.     

Spontaneous Pneumothorax and Lung Carcinoma: Should One Consider Synchronous Malignant Pleural Mesothelioma?

We describe the clinical and pathologic findings of a 68-year-old smoker with previous asbestos exposure who presented with spontaneous hydropneumothorax and was diagnosed with synchronous undifferentiated lung carcinoma and incidental malignant pleural mesothelioma. The synchronous occurrence of these two neoplasms is an extremely rare event with fewer than 20 reported cases in the English literature. The accurate diagnosis of synchronous tumors can be extremely challenging and the identification of a concomitant mesothelioma in our case was not made until an extensive immunohistochemical analysis was done on the resection specimen. Spontaneous pneumothorax occurs much more commonly in patients with malignant mesothelioma than with primary lung carcinomas. Consequently, although synchronous pleural mesotheliomas and lung carcinomas are infrequent, this diagnosis should be considered when a patient with a lung mass and a history of asbestos exposure presents with spontaneous pneumothorax and pleural thickening on imaging. Identification of synchronous tumors is of critical importance for determining the patient's stage and management and can have significant medicolegal implications should the patient seek compensation.