Integration of Multimodality Approaches in the Management of Malignant Pleural Mesothelioma

18F-fluorodeoxyglucose positron emission tomography in malignant pleural mesothelioma: diagnostic and prognostic performance and its correlation to pathological results

Although 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) scan has been generally validated in the staging of malignant pleural mesothelioma (MPM), its diagnostic and prognostic performances are not clearly established. Aiming to identify possible factors causing 18F-fluorodeoxyglucose PET/CT false-negative results and influencing prognosis in MPM patients, we analysed clinical, radiometabolic and pathological features in 141 MPM patients who underwent diagnostic 18F-fluorodeoxyglucose PET/CT scan (January 2009-July 2018) at 2 high-volume institutions. The Fisher's exact test and the Cox model were used in statistical analysis. Overall detection rate was 88.3% with 16 patients (11.6%) presenting with a standardized uptake value (SUV) max <2.5 (PET-negative). PET-negative cases were more frequently detected in older patients (P = 0.027) and early-stage tumours (33.3% false-negative in stage I and 40.0% false-negative in T1-tumours, with P = 0.014 both). Mean SUVmax value was higher in sarcomatoid (11.8 ± 4.6) and biphasic MPM (9.3 ± 7.0), rather than in epithelioid MPM (6.9 ± 3.8, P < 0.001). Concerning overall survival, SUVmax (both as continuous and as categorical variable) was found to be a prognostic factor, in addition to stage (P = 0.032) and histology (P = 0.014) as confirmed by multivariable analysis (hazard ratio 2.65, confidence interval 1.23-5.70; P < 0.001). In the light of such results, we highlight that a low fluorodeoxyglucose uptake might be observed in more than 10% MPMs, especially in early-stage tumours affecting elderly patients. Furthermore, high SUVmax values significantly correlated with a worse prognosis.

18F-FDG PET/CT in the management of patients with malignant pleural mesothelioma being considered for multimodality therapy: experience of a tertiary referral center

OBJECTIVE

To compare the N- and M-staging accuracy of PET vs CT, as per the American Joint Committee on Cancer (AJCC) eighth edition in patients with malignant pleural mesothelioma (MPM) being considered for multimodality therapy in a tertiary referral center. A secondary aim was to assess survival outcome of patients chosen for surgical management after PET.

METHODS

A retrospective, single institution comparison of PET and CT was performed in patients with histologically proven MPM being considered for multimodality therapy. Performance of each modality in identifying nodal category and presence or absence of distant metastases was abstracted from electronic patient records. The standard of reference was surgical histopathology for nodal stage and histopathology or clinical and imaging follow-up of >3 months for distant metastases.

RESULTS

There were 101 eligible patients with complete data sets; 82 males, 19 females with a mean age of 66.6 years (range: 39-85). Most patients (n = 68) had epithelioid histology. Surgery was performed in 61/101 patients (60.4%), most of whom had multimodality therapy. Nodal category was concordant to surgical histopathology in 38/60 patients (63.3%) on PET, compared to 27/60 (45%) on CT (p = 0.001). For detection of ≥N1 disease only, PET and CT correctly staged 15/37 patients (40.5%) and 8/37 (21.6%), respectively (p = 0.023). Distant metastases were identified uniquely on PET in eight patients and on CT only in one patient. Overall, PET and CT correctly identified 11/12 (91.6%) and 4/12 (33.3%) patients with distant metastases, respectively (p = 0.0391).

CONCLUSION

PET identifies significantly more patients with nodal or distant metastatic disease than CT and may contribute to more appropriate selection of patients with MPM for surgery or multimodality therapy. Advances in knowledge: In patients with MPM, fludeoxyglucose-PET/CT detects significantly more patients with distant metastases than CT. PET/CT can help in the selection of patients with MPM who would benefit from surgery or multimodality therapy.

Comparison between Plasma and Serum Osteopontin Levels: Usefulness in Diagnosis of Epithelial Malignant Pleural Mesothelioma

Background

A potential role of serum osteopontin (OPN) and serum mesothelin-related peptide (SMRP) in the diagnosis of malignant pleural mesothelioma (MPM) has been recently reported. Although the most important data regarding the role of OPN in MPMs derive from the marker's measurement in serum samples, most commercial laboratory kits for OPN assay are suitable only for measuring plasma levels, as indicated by the manufacturers. Our study aimed to evaluate the influence of preanalytic variables on serum and plasma OPN, to compare serum and plasma OPN in the same population, and to assess whether OPN levels can aid in the diagnostic distinction of patients with MPM versus benign respiratory disease (BRD) and healthy subjects exposed to asbestos.

Methods

The influence of preanalytic variables such as the length of storage at different temperatures and the number of thawings of samples on serum and plasma OPN measurements were evaluated. We measured OPN in 239 plasma samples from 207 asbestos-exposed subjects including 94 healthy controls and 113 subjects with BRD, and 32 patients with epithelial MPM, employing a commercially available ELISA. Serum OPN was measured in 196 of the same 239 samples from 80 healthy subjects, 92 BRD patients and 24 MPM patients.

Results

We found that both serum and plasma OPN levels were influenced by storage at –80°C and by the number of thawings, while serum OPN was influenced also by storage at room temperature. Plasma and serum OPN levels were significantly higher (p<0.0001) in patients with epithelial MPM than in the healthy control group and the BRD group. The application of a ROC curve for plasma OPN resulted in an AUC value of 0.780 with a best cutoff of 878.65 ng/mL, with a sensitivity of 68.8% and a specificity of 84.5%. The AUC for sOPN was 0.725 with a best cutoff of 16.06 ng/mL, with a sensitivity of 62.5% and a specificity of 87.3%. Within the control group no significant correlation was observed between age, duration of asbestos exposure, pack-years in current smokers, lung function or imaging parameters and plasma or serum OPN.

Conclusions

These data suggest that plasm OPN and serum OPN are not influenced by confounding factors such as age, smoking habits and asbestos exposure. Plasma and serum OPN may be useful markers in the diagnosis of epithelial MPM in addition to traditional radiological exams. However, in our opinion plasma OPN is preferable to serum OPN because it is more stable and measurements of OPN in serum are less reliable.

Local and systemic therapies for malignant pleural mesothelioma

OPINION STATEMENT

Malignant pleural mesothelioma (MPM) is a challenging disease to treat with median overall survival times ranging between 9-17 months for all stages of disease. Recent clinical trials have improved our understanding of the biology of MPM. However, survival results are still not ideal. For early-stage MPM, patients should be evaluated for trimodality therapy in an experienced cancer center. If treating off-protocol, MPM patients should receive a surgical staging evaluation. The decision to proceed with surgical resection also should be considered after an extensive and thorough pulmonary and cardiac evaluation. If deemed a good surgical candidate, patients should receive surgical resection (pleurectomy/decortication or extrapleural pneumonectomy), adjuvant radiation therapy (hemithoracic external beam or intensity modulated radiation therapy), and either neoadjuvant or adjuvant chemotherapy (cisplatin-pemetrexed for 4 cycles). The optimal precise sequence of the trimodality is unclear and should be decided upon by a multidisciplinary consensus for each individual patient. In general, clinical trial participation should be encouraged. Several trials are currently underway to examine intraoperative therapies, vaccines, immunotherapy additions, and novel radiation therapy techniques. Advances in the field of MPM are reliant on participation in clinical trials and identifying biomarkers that are predictive for response to systemic therapies and prognostic for survival benefit.

Combination of ascorbate/epigallocatechin-3-gallate/gemcitabine synergistically induces cell cycle deregulation and apoptosis in mesothelioma cells

Malignant mesothelioma (MMe) is a poor-prognosis tumor in need of innovative therapies. In a previous in vivo study, we showed synergistic anti-MMe properties of the ascorbate/epigallocatechin-3-gallate/gemcitabine combination. We have now focused on the mechanism of action, showing the induction of apoptosis and cell cycle arrest through measurements of caspase 3, intracellular Ca(2+), annexin V, and DNA content. StellArray™ PCR technology and Western immunoblotting revealed DAPK2-dependent apoptosis, upregulation of cell cycle promoters, downregulation of cell cycle checkpoints and repression of NFκB expression. The complex of data indicates that the mixture is synergistic in inducing cell cycle deregulation and non-inflammatory apoptosis, suggesting its possible use in MMe treatment.

A predictive equation to adjust for clinical variables in soluble mesothelin-related protein (SMRP) levels

BACKGROUND

Malignant mesothelioma (MM) is an aggressive pleural tumor which is difficult to diagnose in its early stages. Thus, biomarkers for MM including soluble mesothelin-related protein (SMRP) are currently an area of intense research interest. However, SMRP is affected by several factors other than malignancy which need to be taken into account in the individual patient. This study aimed to evaluate factors required to adjust SMRP levels for such variables and produce a useful prediction equation for clinical application.

METHODS

Serum SRMP levels were measured in 535 subjects formerly exposed to asbestos and silica, including many with asbestos-related disorders (ARDs). Linear regression analyses were used to quantify the strength and “ direction ” of the relationship between SMRP and several independent variables,and 2 × 2 tables were used to determine the diagnostic accuracy of SMRP levels, taking into account clinical variables.

RESULTS

SMRP levels were affected by age and glomerular filtration rate (GFR), which were strong confounders in this study. Body mass index (BMI) was also an initial confounder but lost significance after other factors were taken into account.SMRP was also affected by smoking. Poor sensitivity (15.1 % )for SMRP values among subjects with non-malignant asbestos-related disorders was found when compared to currently healthy subjects with a history of asbestos exposure.

CONCLUSIONS

The present study proposes an equation based on age and GFR to improve diagnostic accuracy of SMRP.The poor sensitivity of SMRP found in this study suggests that further work is needed to fi nd new candidate biomarkers for diagnosing early stage MM.

Application of proteomics to soft tissue sarcomas

Soft tissue sarcomas are rare and account for less than 1% of all malignant cancers. Other than development of intensive therapies, the clinical outcome of patients with soft tissue sarcoma remains very poor, particularly when diagnosed at a late stage. Unique mutations have been associated with certain soft tissue sarcomas, but their etiologies remain unknown. The proteome is a functional translation of a genome, which directly regulates the malignant features of tumors. Thus, proteomics is a promising approach for investigating soft tissue sarcomas. Various proteomic approaches and clinical materials have been used to address clinical and biological issues, including biomarker development, molecular target identification, and study of disease mechanisms. Several cancer-associated proteins have been identified using conventional technologies such as 2D-PAGE, mass spectrometry, and array technology. The functional backgrounds of proteins identified were assessed extensively using in vitro experiments, thus supporting expression analysis. These observations demonstrate the applicability of proteomics to soft tissue sarcoma studies. However, the sample size in each study was insufficient to allow conclusive results. Given the low frequency of soft tissue sarcomas, multi-institutional collaborations are required to validate the results of proteomic approaches.

[Usefulness of 18F-FDG PET-CT in the presurgical assessment of malignant pleural mesothelioma treated with neoadjuvant chemotherapy]

Malignant pleural mesothelioma is a relatively rare, but highly aggressive, tumor, associated to exposure to asbestos, with a life expectancy between 9 and 17 months. Chest pain and dyspnea are the most frequent symptoms. The most commonly used therapy is surgery accompanied by chemotherapy. Preoperative assessment, after chemotherapy, has been done using magnetic resonance imaging and computed tomography (CT). However, these techniques cannot predict early response to therapy, because of the slow structural change of the tumor. The aim of this case report is to review and learn about the growing use of PET-CT imaging with (18)F-FDG in the preoperative staging of malignant pleural mesothelioma and its influence in selecting the most appropriate type of surgery.

Comparison of CT and integrated PET-CT based radiation therapy planning in patients with malignant pleural mesothelioma

BACKGROUND

When combined with adequate tumoricidal doses, accurate target volume delineation remains to be the one of the most important predictive factors for radiotherapy (RT) success in locally advanced or medically inoperable malignant pleural mesothelioma (MPM) patients. Recently, 18-fluorodeoxyglucose positron emission tomography (PET) has demonstrated significant improvements in diagnosis and accurate staging of MPM. However, role of additional PET data has not been studied in RT planning (RTP) of patients with inoperable MPM or in those who refuse surgery. Therefore, we planned to compare CT with co-registered PET-CT as the basis for delineating target volumes in these patients group.

METHODS

Retrospectively, the CT and co-registered PET-CT data of 13 patients with histologically proven MPM were utilized to delineate target volumes separately. For each patient, target volumes (gross tumor volume [GTV], clinical target volume [CTV], and planning target volume [PTV]) were defined using the CT and PET-CT fusion data sets. The PTV was measured in two ways: PTV1 was CTV plus a 1-cm margin, and PTV2 was GTV plus a 1-cm margin. We analyzed differences in target volumes.

RESULTS

In 12 of 13 patients, compared to CT-based delineation, PET-CT-based delineation resulted in a statistically significant decrease in the mean GTV, CTV, PTV1, and PTV2. In these 12 patients, mean GTV decreased by 47.1% +/- 28.4%, mean CTV decreased by 38.7% +/- 24.7%, mean PTV1 decreased by 31.1% +/- 23.1%, and mean PTV2 decreased by 40.0% +/- 24.0%. In 4 of 13 patients, hilar lymph nodes were identified by PET-CT that was not identified by CT alone, changing the nodal status of tumor staging in those patients.

CONCLUSION

This study demonstrated the usefulness of PET-CT-based target volume delineation in patients with MPM. Co-registration of PET and CT information reduces the likelihood of geographic misses, and additionally, significant reductions observed in target volumes may potentially allow escalation of RT dose beyond conventional limits potential clinical benefits in tumor control rates, which needs to be tested in future studies.

Malignant pleural mesothelioma

Malignant pleural mesothelioma (MPM) is a deadly disease that occurs in 2,000 to 3,000 people each year in the United States. Although MPM is an extremely difficult disease to treat, with the median overall survival ranging between 9 and 17 months regardless of stage, there has been significant progress over the last few years that has reshaped the clinical landscape. This article will provide a comprehensive discussion of the latest developments in the treatment of MPM. We will provide an update of the major clinical trials that impact mesothelioma treatment in the resectable and unresectable settings, discuss the impact of novel therapeutics, and provide perspective on where the clinical research in mesothelioma is moving. In addition, there are controversial issues, such as the role of extrapleural pneumonectomy, adjuvant radiotherapy, and use of intensity-modulated radiotherapy versus hemithoracic therapy that will also be addressed in this manuscript.

Neoadjuvant and intrapleural therapies for malignant pleural mesothelioma

Historically, malignant pleural mesothelioma patients with potentially resectable disease have been treated with surgery and radiation alone. With improvements in systemic and intrapleural treatment options, a movement toward multi-modality therapy has become more common. Systemic treatment options largely consist of neoadjuvant chemotherapy with platinum doublets and most recently novel targeted agents, such as dasatinib. Intrapleural strategies have included injecting chemotherapy, chemotherapy with hyper thermic per fusion, gene therapy, and immunotherapy. The following review discusses the latest results in neoadjuvant and intrapleural therapies in malignant pleural mesothelioma.

Asbestos-related occupational lung diseases in NSW, Australia and potential exposure of the general population

Asbestos is a fibrous silicate which is recognized as causing a variety of lung disorders including malignant mesothelioma of the pleura, lung cancer and asbestosis. Asbestos use has been banned in most developed countries but exposure still occurs under strict regulation in occupational settings and also occasionally in domestic settings. Although the hazards of asbestos are well known in developed countries, awareness of its adverse health effects is less in other parts of the world, particularly when exposure occurs in non-occupational settings. Experience of asbestos use and its adverse heath effects in developed countries such as Australia have resulted in development of expertise in the diagnosis and treatment of asbestos-related diseases as well as in screening and this can be used to help developing countries facing the issue of asbestos exposure.

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.

Soluble mesothelin-related protein in an asbestos-exposed population: the dust diseases board cohort study

RATIONALE

Soluble mesothelin-related protein (SMRP) is raised in epithelial-type malignant mesothelioma (MM), but the utility of SMRP in screening for MM is unknown.

OBJECTIVES

We aimed to evaluate SMRP in an asbestos-exposed cohort.

METHODS

A total of 538 subjects were studied. Those with elevated SMRP (> or =2.5 nM) underwent further investigation including positron emission tomography/computed tomography.

MEASUREMENTS AND MAIN RESULTS

Mean (+/-SD) SMRP in healthy subjects exposed to asbestos (n = 223) was 0.79 (+/-0.45) nM. Fifteen subjects had elevated SMRP, of whom one had lung cancer, which was successfully resected. Another with lung cancer was undetected by SMRP. No subjects were diagnosed with MM. Mean SMRP in healthy subjects was significantly lower than in subjects with pleural plaques alone (P < 0.01).

CONCLUSIONS

This is the first large-scale prospective study of SMRP for screening for malignancy in asbestos-exposed individuals. A high false-positive rate was observed. SMRP seems unlikely to prove useful in screening for MM.

Current therapies for malignant pleural mesothelioma

Mesothelioma is a highly lethal tumor derived from mesothelial cells, and its global incidence is increasing because of widespread exposure of numerous individuals to asbestos in the last 50 years. Mesothelioma is largely untreatable with any of the therapeutic modalities. Recently, a novel multitargeted antifolate pemetrexed has shown promising activity against malignant pleural mesothelioma, producing response rates of up to 40% when used in combination with cisplatin. In a large phase III study, use of a combination of pemetrexed and cisplatin was associated with significantly improved survival time and with greater antitumor activity compared with cisplatin alone. This combination also gave a significant response rate of approximately 50% in patients with epithelioid malignant pleural mesothelioma. These clinical benefits of pemetrexed-cisplatin doublet have changed the perception of mesothelioma chemotherapy. Other combinations, including gemcitabine in combination with cisplatin, have also shown encouraging response rates. Prognosis depends on gender, clinical stage of the tumor, histological subtype, platelet count, leukocyte counts, and performance status. Radiotherapy can palliate mesothelioma patients with chest pain, and has been indicated to be of benefit for the prevention of malignant seeding along the tract of a chest tube or needle biopsy. Trimodality treatment using extrapleural pneumonectomy, radiation and chemotherapy has shown promising therapeutic value. The development of chemotherapeutic regimens and the favorable outcomes of trimodality have led to new combined modality trials. In Japan, multicenter national trials against mesothelioma will begin in the near future.

Ranpirnase--an antitumour ribonuclease: its potential role in malignant mesothelioma

Ranpirnase (Onconase) is a novel cytotoxic ribonuclease. In clinical development as a single agent in patients with malignant mesothelioma (MM), at 480 microg/m2 intravenously weekly, analysis of survival indicated prolonged periods of stable disease in Phase II trials and a potential survival benefit, compared with doxorubicin, in a small unpublished Phase III trial. In all clinical studies it has generally demonstrated a favourable safety profile except for easily controlled allergic reactions and dose modifications for renal impairment. Standard first-line treatment for MM has recently been established with an antifolate and cisplatin. At present, a Phase III trial of doxorubicin with or without ranpirnase is nearing completion in MM patients without prior chemotherapy or one prior chemotherapy regimen.

Autoantibody biomarkers in the detection of cancer

By definition, tumor biomarkers are selective molecules that can distinguish between patients with cancer and controls. Serum tumor markers have been the most widely used approach for cancer detection. However, the limitations of these markers, which are based on the measurement of tumor antigens, preclude their general use in cancer screening and diagnosis. Here we give an overview of recent cancer biomarker developments based on the detection of autoantibodies produced against tumor antigens in patients' sera. This new detection method can measure the autoantibodies for a spectrum of tumor antigens in a single assay, with sensitivity and specificity exceeding those obtained using the conventional antigen determination method. Autoantibodies against serum cancer biomarkers offer a novel technology for cancer detection.

Preoperative Evaluation of Patients With Malignant Pleural Mesothelioma: Role of Integrated CT-PET Imaging

Malignant pleural mesothelioma (MPM) is an uncommon neoplasm arising from mesothelial cells of the pleura. The prognosis is poor with a median survival of 8 to 18 months after diagnosis. Multimodality regimens combining chemotherapy, radiotherapy, immunotherapy, and surgery are being used more frequently in patient management. Extrapleural pneumonectomy is the surgical treatment of choice in 10% to 15% of patients who present with resectable disease and is reported to prolong survival. Accurate staging is important to distinguish patients who are resectable from those requiring palliative therapy. Integrated computed tomography-positron emission tomography (CT-PET) increases the accuracy of overall staging in patients with MPM and significantly improves the selection of patients for curative surgical resection. Specifically, CT-PET detects more extensive disease involvement than that shown by other imaging modalities and is particularly useful in identifying occult distant metastases. This article reviews aspects of imaging performed in the initial staging of patients with MPM according to the International Mesothelioma Interest Group staging system and will emphasize the appropriate role of CT-PET imaging in determining the T, N, and M descriptors.

Asbestos exposure, pleural mesothelioma, and serum osteopontin levels

BACKGROUND

We investigated the presence of osteopontin in pleural mesothelioma and determined serum osteopontin levels in three populations: subjects without cancer who were exposed to asbestos, subjects without cancer who were not exposed to asbestos, and patients with pleural mesothelioma who were exposed to asbestos.

METHODS

A group of 69 subjects with asbestos-related nonmalignant pulmonary disease were compared with 45 subjects without exposure to asbestos and 76 patients with surgically staged pleural mesothelioma. Tumor tissue was examined for osteopontin by immunohistochemical analysis, and serum osteopontin levels were measured by an enzyme-linked immunosorbent assay.

RESULTS

There were no significant differences in mean (+/-SE) serum osteopontin levels between age-matched subjects with exposure to asbestos and subjects without exposure to asbestos (30+/-3 ng per milliliter and 20+/-4 ng per milliliter, respectively; P=0.06). In the group with exposure to asbestos, elevated serum osteopontin levels were associated with pulmonary plaques and fibrosis (56+/-13 ng per milliliter) but not with normal radiographic findings (21+/-5 ng per milliliter), plaques alone (23+/-3 ng per milliliter), or fibrosis alone (32+/-7 ng per milliliter) (P=0.004). Serum osteopontin levels were significantly higher in the group with pleural mesothelioma than in the group with exposure to asbestos (133+/-10 ng per milliliter vs. 30+/-3 ng per milliliter, P<0.001). Immunohistochemical analysis revealed osteopontin staining of the tumor cells in 36 of 38 samples of pleural mesothelioma. An analysis of serum osteopontin levels comparing the receiver-operating-characteristic curve in the group exposed to asbestos with that of the group with mesothelioma had a sensitivity of 77.6 percent and a specificity of 85.5 percent at a cutoff value of 48.3 ng of osteopontin per milliliter. Subgroup analysis comparing patients with stage I mesothelioma with subjects with exposure to asbestos revealed a sensitivity of 84.6 percent and a specificity of 88.4 percent at a cutoff value of 62.4 ng of osteopontin per milliliter.

CONCLUSIONS

Serum osteopontin levels can be used to distinguish persons with exposure to asbestos who do not have cancer from those with exposure to asbestos who have pleural mesothelioma.

Human mesothelioma cells exhibit tumor cell–specific differences in phosphatidylinositol 3-kinase/AKT activity that predict the efficacy of Onconase

Malignant mesothelioma is an aggressive cancer with no known cure, which has become a therapeutic challenge. Onconase is one of few chemotherapeutic agents that have been studied in patients with malignant mesothelioma that has the advantage of low toxicity and limited side effects. Here, we evaluate the effect of Onconase on killing of malignant mesothelioma cells and how the phosphatidylinositol 3-kinase/AKT (PI3-K/AKT) survival pathway influences this effect. Our results show that Onconase induces apoptosis in malignant mesothelioma cell lines and that this effect is tumor cell specific. Malignant mesothelioma cell lines with the highest AKT activation, which correlated with the presence of the SV40 large and small T antigen (SV40+), were the most resistant to the drug. Finally, a cooperative effect was observed between small molecule inhibitors of PI3-K and Onconase in the killing of malignant mesothelioma cells. Our results suggest that kinase screening of individual malignant mesotheliomas for endogenous levels of activated PI3-K/AKT may be predictive of the efficacy of Onconase and possibly other chemotherapeutic agents.

Macrophage migration inhibitory factor and CXC chemokine expression in non-small cell lung cancer: role in angiogenesis and prognosis

PURPOSE

The purpose of this study was to determine whether expression of migration inhibitory factor (MIF) is increased in non-small cell lung cancer, and whether it correlates with angiogenesis and/or prognosis.

EXPERIMENTAL DESIGN

We measured vessel density, and levels of MIF, angiogenic CXC chemokines, and vascular-endothelial growth factor (VEGF; by ELISA) in tumor and normal lung tissue from 87 patients after resection of lung cancer. We compared vessel density with levels of MIF, VEGF, or angiogenic CXC chemokines in the corresponding tumor homogenate. Disease-free survival was analyzed in a Cox proportional hazards model.

RESULTS

Levels of MIF in lung cancer demonstrated a bimodal distribution, with some having "normal" values (relative to normal lung tissue) and a second cluster with markedly high values. The increased levels of MIF in lung cancer were statistically significant in both paired and unpaired comparisons (P < 0.05). The strongest correlation of vessel density was with the sum of angiogenic CXC chemokines. MIF correlated very strongly with levels of angiogenic CXC chemokines. Tumors in the high MIF group had a strong correlation between MIF level and vessel density. Risk of recurrence was associated with high levels of glutamic acid-leucine-arginine amino acid motif CXC chemokines, MIF, and/or VEGF in a Cox proportional hazards model.

CONCLUSIONS

MIF expression in non-small cell lung cancer occurs in a bimodal distribution, and is closely associated with tumor levels of angiogenic CXC chemokines and with vessel density. High levels of tumor-associated CXC chemokines, MIF, or VEGF are associated with risk of recurrence after resection of lung cancer.