Intrapleural chemotherapy for patients with incompletely resected malignant mesothelioma: the UCLA experience

Antineoplastic activity of povidone-iodine on different mesothelioma cell lines: results of in vitro study

OBJECTIVE

Povidone-iodine (PVP-I) or Betadine, owing to its antineoplastic activity, is also used as an adjuvant during intra-abdominal or intrathoracic surgery. However, the protocol of PVP-I administration has not been optimized to achieve the best antitumoural efficacy. We aimed to determine the optimal concentration of PVP-I, the time of incubation and the mechanism of cell death by analysing the effect of different doses and time of administration of PVP-I on the cell viability of different mesothelioma cell lines.

METHODS

Four different cell lines (MET 5A/normal mesothelium; H2052/sarcomatoid mesothelioma; ISTMES2/epithelial mesothelioma; MSTO/biphasic mesothelioma) were incubated with increasing concentrations of diluted PVP-I (0.0001; 0.001; 0.01; 0.1; 1%) for 5, 10, 30, 60 min and 24 h, respectively. Cell viability was determined using cell direct cytotoxicity assay and cell death was determined through flow cytometry assay analysis. The superoxide dismutase activity was assessed functionally through a specific inhibitor to evaluate the mechanism of cell death.

RESULTS

The antiproliferative effect of PVP-I varied largely among different cell lines in a dose- and time-dependent manner. At 0.1% concentration for 10 min of incubation, the percentage of viable cells was 0.5 ± 0.1; 0.8 ± 0.5 and 0% (P < 0.01) for MET5A, ISTMES2 and MSTO, respectively. Conversely, the same concentration did not significantly affect the H2052 cell line which was completely suppressed at a 1% concentration of PVP-I. Double staining of Annexin V and DNA showed that PVP-I induced cell death in all four cell lines via necrosis depending on PVP-I concentration. However, H2052 was found to be more resistant than MSTO, ISTMES2 and MET 5A cells lines. The activity of superoxide dismutase was significantly inhibited in all cell lines.

CONCLUSIONS

Our results confirmed the anti-neoplastic activity of PVP-I especially on ISTMES2 and MSTO cell lines. With respect to chemotherapy pleural irrigation, washing with PVP-I is cost-effective and easy. If confirmed by larger studies, our findings suggest that the intrapleural irrigation with PVP-I (0.1% concentration for 10 min) in patients with epithelial or biphasic mesothelioma undergoing cytoreductive surgery might be applied in thoracic surgery practice to prevent neoplastic cell growth.

Malignant paratesticular mesothelioma

Mesothelioma of the tunica vaginalis testis (MTVT) is a rare tumor that usually affects patients after the sixth decade of life. Exposure to asbestos is a known risk factor. Enlargement of the scrotal volume is the most common initial clinical manifestation, and about 15% of cases present metastasis at diagnosis. The treatment relies on surgical resection while the role of adjuvant chemotherapy and radiotherapy remains unclear. The prognosis for patients is generally poor, with a lethal outcome in 30% over a 24-month period. The authors report a case of a 62-year-old patient with the diagnosis of MTVT without a history of asbestos exposure. After surgical treatment, metastatic disease ensued. Chemotherapy was initiated, but could not be continued due to marked and fast clinical deterioration. The authors call attention to the difficulty of early diagnosis of MTVT due to a nonspecific clinical picture, the lack of action by the patient when the scrotal enlargement was first noticed, and the lack of tumor markers. Delayed diagnosis is definitely related to unfavorable prognosis.

Malignant paratesticular mesothelioma

Mesothelioma of the tunica vaginalis testis (MTVT) is a rare tumor that usually affects patients after the sixth decade of life. Exposure to asbestos is a known risk factor. Enlargement of the scrotal volume is the most common initial clinical manifestation, and about 15% of cases present metastasis at diagnosis. The treatment relies on surgical resection while the role of adjuvant chemotherapy and radiotherapy remains unclear. The prognosis for patients is generally poor, with a lethal outcome in 30% over a 24-month period. The authors report a case of a 62-year-old patient with the diagnosis of MTVT without a history of asbestos exposure. After surgical treatment, metastatic disease ensued. Chemotherapy was initiated, but could not be continued due to marked and fast clinical deterioration. The authors call attention to the difficulty of early diagnosis of MTVT due to a nonspecific clinical picture, the lack of action by the patient when the scrotal enlargement was first noticed, and the lack of tumor markers. Delayed diagnosis is definitely related to unfavorable prognosis.

Systematic review of pleurectomy in the treatment of malignant pleural mesothelioma

INTRODUCTION

Pleurectomy/decortication (P/D) in the treatment of malignant pleural mesothelioma includes a number of procedures with different clinical indications and therapeutic intents. To unify the nomenclature, IMIG and IASLC recently defined P/D-related procedures according to surgical technique, including 'extended P/D', 'P/D' and 'partial pleurectomy'. The present systematic review aimed to assess the safety and efficacy of these techniques.

METHODS

A systematic review of relevant studies was performed by electronic search of five online databases from 1985 to 2012 by two independent reviewers according to predefined selection criteria.

RESULTS

Thirty-four studies involving 1916 patients who underwent pleurectomy were included for quantitative analysis. These included 12 studies on 'extended P/D', 8 studies on 'P/D' and 14 studies on 'partial pleurectomy'. Perioperative mortality ranged from 0% to 11% and perioperative morbidity ranged from 13% to 43%. Median overall survival ranged from 7.1 to 31.7 months and disease-free survival ranged from 6 to 16 months. One study reported on quality-of-life outcomes using a standardized questionnaire suggesting superior outcomes for 'extended P/D' compared to extrapleural pneumonectomy.

CONCLUSIONS

Results of the present systematic review suggested similar perioperative mortality outcomes between different P/D techniques but a trend towards higher morbidity and length of hospitalization for patients who underwent 'extended P/D'. However, overall and disease-free survival appeared to favour 'extended P/D' compared to less aggressive techniques. Future studies on P/D should adhere to recent definitions to enable accurate analysis of similar procedures. Direct comparisons of pleurectomy to extrapleural pneumonectomy remain challenging, and should be restricted to 'extended P/D' procedures only.

Recommendations for uniform definitions of surgical techniques for malignant pleural mesothelioma: a consensus report of the international association for the study of lung cancer international staging committee and the international mesothelioma interest group

INTRODUCTION

Extrapleural pneumonectomy has been well defined; however, surgeons vary regarding the surgical extent and goals of "pleurectomy/decortication" (P/D). We explored mesothelioma surgeons' concepts of P/D with the aim of unifying surgical nomenclature.

METHODS

A web-based survey was administered to surgeons who operated on malignant pleural mesothelioma (MPM) for diagnosis, staging, palliation, or cytoreduction. One hundred thirty surgeons from 59 medical centers were included. Surgeons who did not perform surgery for MPM within the last year were excluded.

RESULTS

There were 62 (48%) respondents from 39 medical centers in 14 countries. The mean number of patients with MPM seen annually at each medical center was 46, and the mean annual number of cytoreductive procedures performed per surgeon was 8. Most (88%) agreed that the goal of cytoreductive surgery should be macroscopic complete resection of tumor. P/D was defined as resection of parietal and visceral pleura with the aim of achieving macroscopic complete resection by 72% of respondents. If the diaphragm or pericardium required resection, 64% preferred the term "radical P/D," whereas "P/D" (40%) or "total pleurectomy" (39%) was preferred if these structures were not removed. Most surgeons believed that extrapleural pneumonectomy (90%) or "radical P/D" (68%) could provide adequate cytoreduction, whereas only 23% thought that P/D could.

CONCLUSIONS

There was significant variation regarding surgical nomenclature for procedures for MPM. The International Staging Committee of the International Association for the Study of Lung Cancer and the International Mesothelioma Interest Group recommend that P/D should aim to remove all macroscopic tumor involving the parietal and visceral pleura and should be termed "extended" P/D when the diaphragm or pericardium is resected.

A systematic review of lung-sparing extirpative surgery for pleural mesothelioma

OBJECTIVES

There is a resurgence of interest in lung-sparing extirpative surgery for malignant pleural mesothelioma with recent reports of better survival and fewer adverse consequences than with extrapleural pneumonectomy. However, these operations are not well-characterized and to offer evidence-based clinical recommendations and to plan future trials a summary of what is already known is required.

DESIGN

A formal literature search was performed and all recovered titles were sequentially sifted by title, abstract and full-text reading according to prespecified criteria. Papers were selected if they contained data relevant to the area of enquiry. Quantitative synthesis and textual analysis, appropriate to the material, were performed.

SETTING

Follow-up studies of patients undergoing surgery for malignant pleural mesothelioma in specialist thoracic or cardiothoracic units.

PARTICIPANTS

Among the operated patients described in these papers, a total of 1270 patients had undergone lung-sparing surgery for mesothelioma.

RESULTS

There were no randomized trials or other forms of controlled studies. From 464 titles, 26 papers contained sufficient data on 1270 patients to be included in the systematic review. Operative descriptions for all series were extracted and tabulated and variation was found in the nature of surgery within and between series, and the degree of detail with which it was described. There was more operative detail in recent papers. All available numerical data were extracted, tabulated and summarized using quantitative methods. The average survival at 1, 2, 3, 4 and 5 years was 51%, 26%, 16%, 11% and 9%, respectively. There were no data on patients' performance status, symptomatic change, or other patient reported outcomes.

CONCLUSIONS

In the absence of any form of control data, no conclusions can be drawn concerning survival differences or symptomatic benefits attributable to surgery. As mesothelioma surgery is restricted to a selected minority of patients who often have multiple therapies, future research will require controlled studies with explicit definitions of the clinical and surgical intent.

Optimized intrapleural cisplatin chemotherapy with a fibrin carrier after extrapleural pneumonectomy: a preclinical study

OBJECTIVE

Our objective was to evaluate whether platinum concentrations in chest wall tissue and in serum are optimized by intracavitary application of cisplatin loaded to a fibrin carrier compared with cisplatin solution in a randomized setting of a pig model.

METHODS

After left-sided pneumonectomy including parietal pleurectomy, pigs were randomly assigned to receive either 90 mg/m(2) cisplatin intracavitary solution (n = 6) or to receive 5 mg cisplatin-fibrin (n = 5) applied on a predefined area of the chest wall. Platinum concentration in serum as well as in chest wall tissue was determined at several early time points until day 5 after treatment. Platinum levels were measured by inductively coupled plasma sector field mass spectrometric detection with a matrix-matched calibration procedure.

RESULTS

The dose- and surface-corrected (geometric) mean concentration of cisplatin in chest wall tissue 2 hours but also at day 5 after the application was doubled in animals treated with cisplatin-fibrin compared with the animals treated with cisplatin-solution. In serum, the dose- and surface-corrected exposure toward cisplatin (area under the curve(0-5d)) was significantly lower with cisplatin-fibrin than with cisplatin-solution (P < .0005). This is also reflected by significantly reduced serum creatinine and urea values in the cisplatin-fibrin group (P < .0001). Animals treated with cisplatin-fibrin additionally had a significantly better postoperative course as assessed by a well-being score (P < .001).

CONCLUSIONS

After cisplatin-fibrin treatment, cisplatin tissue concentration was increased whereas systemic cisplatin concentrations were significantly reduced in comparison with cisplatin-solution treatment. This finding offers a clear advantage inasmuch as rate and severity of systemic adverse events can be reduced while local cytotoxic concentrations are at least maintained.

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.

Malignant mesothelioma of the tunica vaginalis testis: a case report and literature review

Malignant mesothelioma of the tunica vaginalis testis is a rare but often fatal malignancy. Here, we report one patient with locally advanced disease who has a history of asbestos exposure. We review the literature concerning current management strategies of the disease. Radical surgery plus adjuvant radiotherapy seems to provide the best results.

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.

Biology and management of malignant pleural mesothelioma

Malignant mesothelioma is an aggressive tumour, with a poor prognosis and an increasing incidence as a result of widespread exposure to asbestos. The results of the treatments available are poor. Surgery and radiotherapy have a limited role in highly selected patients and systemic therapy is the only potential treatment option for the majority of patients. Despite some definite activity of the novel antifolates such as pemetrexed and raltitrexed, the results, even in combination with platinating agents, are still modest, with a median survival of approximately one year. The better understanding of the biology of mesothelioma makes the assessment of a number of targeted agents particularly interesting. Unfortunately, the targeted agents imatinib, gefitinib, erlotinib and thalidomide have been shown to be ineffective in unselected patients. Studies with anti-angiogenesis agents are ongoing. An improvement of the knowledge of major molecular pathways involved in malignant mesothelioma is needed in order to define proper targets for the systemic treatment of this disease.

Phase I to II study of pleurectomy/decortication and intraoperative intracavitary hyperthermic cisplatin lavage for mesothelioma

PURPOSE

To evaluate morbidity, mortality, maximum-tolerated dose (MTD), and outcome of intraoperative intracavitary hyperthermic cisplatin lavage in patients undergoing pleurectomy for malignant pleural mesothelioma (MPM).

PATIENTS AND METHODS

Sixty-one patients were prospectively registered. Forty-four resectable patients with MPM underwent pleurectomy, followed by a 1-hour lavage of the resection cavity with dose-escalated cisplatin (50, 100, 150, 175, 200, 225, and 250 mg/m2) at 42 degrees C and then intravenous sodium thiosulfate (16 g/m2 over 6 hours). Survival estimates were compared using the log-rank test and proportional hazards regression.

RESULTS

Median age was 71 years (range, 50 to 82 years). Twenty-four patients had epithelial tumors, and 20 had sarcomatous or mixed histology. Postoperative mortality was 11% (five of 44 patients). Dose-limiting renal toxicity occurred at 250 mg/m2, establishing the MTD at 225 mg/m2. Other morbidity included atrial fibrillation (14 of 44 patients, 32%) and deep venous thrombosis (four of 44 patients, 9%). Median survival time of all registered patients was 9 months, and the median survival time of resected patients was 13 months. Survival estimates differed significantly for resectable patients exposed to low doses (50 to 150 mg/m2; n = 9; median, 6 months) versus high doses (175 to 250 mg/m2; n = 35; median, 18 months) of hyperthermic cisplatin (P = .0019); recurrence-free interval also differed significantly (4 v 9 months, respectively; P < .0001). Low dose level (relative risk = 3.418) and nonepithelial histology (relative risk = 2.336) were independent risk factors for poor survival. Twenty patients with epithelial tumors who underwent high-dose cisplatin lavage had a 26-month median survival time.

CONCLUSION

Pleurectomy and high-dose intraoperative intracavitary hyperthermic cisplatin lavage is feasible in this patient population with restricted surgical options. An apparent dose-related survival benefit warrants further study.

Phase II Study of a Liposome-Entrapped Cisplatin Analog (L-NDDP) Administered Intrapleurally and Pathologic Response Rates in Patients With Malignant Pleural Mesothelioma

Purpose

To determine pathologic response rates to liposome-entrapped cis-bisneodecanoato-trans-R,R-1,2-diaminocyclohexane platinum(II) (L-NDDP) administered intrapleurally in patients with malignant pleural mesothelioma.

Patients and Methods

Thirty-three patients with malignant pleural mesothelioma and free-flowing pleural effusions received intrapleural L-NDDP once every 3 weeks at a dose of 450 mg/m2. Thoracoscopic evaluation with pleural biopsies was performed before therapy and then after every two cycles. The primary end point was pathologic response as determined by thoracoscopic biopsy.

Results

After at least two cycles, post-treatment pleural biopsy analysis was negative in 14 patients for a pathologic response rate of 42% (95% CI, 25% to 61%). Median survival was 11.2 months. There were three treatment-related deaths secondary to peritonitis, cellulitis at the thoracoscopy site, and empyema. Grade 3 nonhematologic toxicities included infection, fever, dyspnea, and anorexia, which occurred in five (15%), one (3%), one (3%), and one (3%) patients, respectively. There were no grade 4 nonhematologic toxicities. Grade 3 or 4 neutropenia, thrombocytopenia, and anemia occurred in five (15%), three (9%), and two (6%) patients, respectively. Two patients with pathologic responses subsequently underwent pleural decortication. Both surgical specimens revealed residual tumor in regions that were not in direct communication with the pleural space.

Conclusion

Intrapleural L-NDDP therapy in this patient population is feasible with significant but manageable toxicity. Although pathologic responses are highly encouraging, areas of mesothelioma that are not in direct communication with the pleural space will evade drug exposure and limit efficacy in some patients. The optimal role of intrapleural L-NDDP therapy currently remains to be determined.

Surgical management of malignant pleural mesothelioma: a systematic review and evidence summary

An evidence summary was developed for the surgical management of adult patients with diffuse or localized malignant pleural mesothelioma. This evidence summary is based on a systematic search and review of the literature published between 1985 and February 2004. Relevant studies were identified, according to pre-determined criteria by the authors and methodologists. No randomized controlled trials comparing pleurectomy (PL) with extrapleural pneumonectomy (EPP) or comparing surgery with an alternative treatment were identified. Four comparative studies, seven non-comparative prospective studies, and 16 retrospective case series were identified that looked at PL, or EPP, or PL and EPP. Trial results were not pooled due to the heterogeneity of the treatments in the trials and the fact that no trials were randomized and none were designed to directly compare different treatments. External feedback was obtained from Ontario clinicians, and the provincial Lung Cancer Disease Site Group approved the review.

CONCLUSIONS

The role of surgery in the management of malignant pleural mesothelioma cannot be precisely defined as the lack of randomized controlled clinical trials makes it impossible to determine whether the use of EPP or PL improves survival or effectively palliates the symptoms of the disease. Future studies of the role of surgery in the treatment of mesothelioma should include evaluations of quality of life.

Innovative therapies: intraoperative intracavitary chemotherapy

Both phase I studies demonstrated that high-dose cisplatin can be delivered safely with acceptable complication rates. The maximum tolerated doses of 225 mg/m2 and 250 mg/m2 cisplatin, respectively, are higher than any other published report of intrapleural cisplatin. The intrapleural cisplatin doses reported in other trials have been 80 mg/m2, 100 mg/m2, and 200 mg/m2. Despite the use of high-dose intraoperative chemotherapy, the group of 50 patients who underwent EPP experienced mortality and morbidity comparable to the contemporaneous group of 41 patients who did not participate in the protocol, except for increased rates of deep venous thrombosis and diaphragmatic patch failure. The 44 patients who underwent P/D experienced a slightly higher mortality rate and creatinine toxicity rate than the first phase I trial. Given the demographics of this patient cohort (higher age, lower FEV1, and inability to withstand pneumonectomy because of limited cardiopulmonary reserve), however, the mortality and morbidity rates seem acceptable. The pharmacologic data from both studies support our hypothesis that high regional doses of cisplatin can be delivered with less systemic absorption than can be achieved with intravenous administration (data not shown). With the maximum tolerated dose of intracavitary cisplatin and safety of intraoperative administration after surgical resection firmly established by these phase I trials, we are prepared to implement phase II and III studies of EPP and P/D with intraoperative cisplatin lavage. We aim to monitor tumor recurrence and patient survival prospectively and compare these results with historic controls. We also intend to document prospectively the morbidity and mortality of the treatment protocols. Finally, we plan to evaluate the pharmacokinetics of cisplatin by measuring tissue and perfusate levels of active and inactive cisplatin. By approaching the problem of local recurrence after resection of MPM in a careful and methodical manner, we hope to decrease or delay the rate of recurrence and potentially improve longterm survival in patients with this lethal disease.

Pleurectomy and decortication for malignant mesothelioma

P/D in combination with other therapies remains an effective weapon in the thoracic surgeon's armamentarium for treating patients with MPM, particularly patients with limited lung function. A clear benefit has been demonstrated in terms of symptom relief. Further strategies aimed at eliminating residual disease in an effort to prevent locoregional recurrence and as potential curative therapies currently are being investigated.

Pemetrexed and its emerging role in the treatment of thoracic malignancies

Pemetrexed (Alimta); Eli Lilly and Co., Indianapolis, IN, USA) is a unique multitargeted antifolate that inhibits at least three enzymes, thymidylate synthase, dihydrofolate reductase and glycinamide ribonucleotide formyltransferase. This novel drug is being evaluated in a comprehensive clinical programme for use in both front-line and second-line therapies. It has shown broad activity in a number of solid tumours, including colon cancer, breast cancer, lung cancer, head and neck, cervical cancer and others. While a number of antifolates have been evaluated in clinical trials, further development has been stopped or delayed by the occurrence of life-threatening toxicities. Similar trends were also initially observed with pemetrexed as well, but investigators later showed that these toxicities could be minimised with folic acid and vitamin B(12) supplementation included in the treatment regimen. Preliminary data indicate that this supplementation does not hamper drug efficacy in most tumour types and in many cases, supplemented patients exhibit improved clinical outcome. Here, the current data for pemetrexed in treating thoracic malignancies are reviewed, with special focus on malignant pleural mesothelioma and non-small cell lung cancer.

Surgical treatment of malignant pleural mesothelioma: a review

Despite many years of clinical research, there is still no effective therapy for malignant pleural mesothelioma (MPM). Untreated, the prognosis is poor, with a median survival of < 1 year. Single-agent or combination chemotherapy as well as radiotherapy have not shown persistent improvements in response or survival. In general, MPM is a disease confined to the pleural cavity for a long time before metastasizing. Therefore, focus on local treatment seems rational. Surgical resection has been considered the mainstay of treatment by some. However, surgery alone results in high recurrence rates, and the survival benefit remains questionable. In recent years, the emphasis has been on surgery combined with adjuvant therapies. In this article, the present state of surgical management of MPM will be reviewed.

Radical pleurectomy/decortication and intraoperative radiotherapy followed by conformal radiation with or without chemotherapy for malignant pleural mesothelioma

OBJECTIVES

We performed a retrospective review of the efficacy and morbidity of radical pleurectomy/decortication and intraoperative radiotherapy followed by external beam radiation therapy with or without chemotherapy for diffuse malignant pleural mesothelioma.

METHODS

A total of 32 patients with diffuse malignant pleural mesothelioma were initially evaluated between January 1995 and September 2000. Three patients were excluded from analysis because of unresectable disease. Two patients died postoperatively, and one patient had recurrent disease previously treated at an outside institution. Of the remaining 26 patients included in the analysis, 24 received intraoperative radiotherapy. External beam radiation therapy was generally started 1 to 2 months after resection and delivered by means of 3-dimensional conformal radiation therapy or with inverse treatment planning intensity-modulated radiation therapy. When given, chemotherapy consisted of 2 to 3 cycles of cyclophosphamide, doxorubicin (Adriamycin), and cisplatin initiated 1 to 2 months after completion of radiation.

RESULTS

At the time of data analysis, 5 of 26 patients were alive. The median follow-up was 9.7 months (range, 2-67.6 months). The median overall survival and progression-free interval from the time of the operation were 18.1 and 12.2 months, respectively. The Kaplan-Meier estimates of overall survival and freedom from progression at 1 year were 64% and 50%, respectively. The site of failure was mostly locoregional. However, there were 4 abdominal failures and 1 contralateral lung failure.

CONCLUSIONS

Radical pleurectomy/decortication with aggressive radiotherapy with or without chemotherapy might offer an alternative treatment option to those who cannot tolerate extrapleural pneumonectomy.

Malignant mesothelioma: options for management

In the past, there has been a tendency to think of diffuse malignant pleural mesothelioma as one disease in therapeutic terms, regardless of histological type and tumor stage. This does not happen with other tumors, yet it is equally illogical and inappropriate in mesothelioma. As with other tumors, early diagnosis-while the disease is still in stage I, or even at an in situ stage-must be the goal so that therapy can be maximized, particularly if immunotherapy or gene therapy is to be used. Patients with pure epithelial mesothelioma have a better prognosis and respond better to trimodality therapy. Stage I patients who meet fitness criteria should be offered the option of radical surgery in combination with chemotherapy and radiotherapy. Further research is required to determine the optimum neoadjuvant and adjuvant modalities, particularly the timing of individual drugs, use of hyperthermia, and route of administration. The place of immunotherapy and gene therapy as adjunctive treatments also remains to be defined. For example, it may be possible to reduce tumor bulk and perhaps downstage the disease with immunotherapy before radical surgery, if treatment is started early enough. Gene therapy may have a role either preoperatively or in destroying the microscopic disease that remains after radical surgery. These and other combinations of treatment need to be tested in well-designed clinical trials, probably on a multicenter basis (to enroll a sufficient number of patients). Finding the means to improve treatment for sarcomatous and mixed histology mesothelioma remains a challenge. At present, radical surgery does not seem worthwhile for these patients when combined with currently employed chemotherapy and radiotherapy; however, chemotherapy combinations used for treating other sarcomas need to be evaluated as adjunctive therapy before radical surgery is abandoned altogether as a mode of treatment. A collaborative approach involving thoracic surgeons, basic scientists and oncologists, and physicians with experience in treating mesothelioma is essential. Despite its increasing frequency, mesothelioma is still a relatively rare tumor, so treatment should be concentrated in relatively few supraregional centers to maximize expertise and allow innovative treatment combinations to be implemented with the greatest chance of success. Evaluation of new therapeutic approaches will be achieved more rapidly if these supraregional centers collaborate in multicenter trials. The nihilistic approach of simply waiting until the mesothelioma epidemic eventually begins to decline spontaneously in 20 or 30 years is untenable in view of the hundreds of thousands of deaths that will result if no effective treatment is found.

Cytoreductive surgery and intraoperative hyperthermic intrathoracic chemotherapy in patients with malignant pleural mesothelioma or pleural metastases of thymoma

STUDY OBJECTIVES

No established curative treatment is available for pleural thymoma metastases and malignant pleural mesothelioma (MPM). Recently, peritoneal malignancies have been treated by cytoreductive surgery and intraoperative hyperthermic intracavitary perfusion chemotherapy (HIPEC). We investigated the feasibility and safety of this multimodality treatment in the thoracic cavity.

DESIGN

Patients with pleural thymoma metastases or early-stage MPM were enrolled in a feasibility study. Morbidity, recurrence, and survival rates were recorded.

SETTING

The Netherlands Cancer Institute.

PATIENTS

Three patients with pleural thymoma metastases and 11 patients with pleural mesothelioma were treated.

INTERVENTIONS

Cytoreductive surgery and intraoperative hyperthermic intrathoracic perfusion chemotherapy (HITHOC) with cisplatin and adriamycin were performed. The mesothelioma patients received adjuvant radiotherapy on the thoracotomy wound and drainage tracts.

MEASUREMENTS AND RESULTS

Morbidity and mortality rates were 47% and 0%, respectively. Reoperation was necessary in four cases. Severe chemotherapy-related complications were not observed. A solitary mediastinal and a contralateral pleural thymoma recurrence were successfully treated by radiotherapy and a contralateral HITHOC procedure. All thymoma patients were alive and free of disease after a mean follow-up period of 18 months. After a mean follow-up period of 7.4 months, nine mesothelioma patients are alive. Two mesothelioma patients died of contralateral pleural and peritoneal recurrent disease, while one patient is alive with locoregional recurrence.

CONCLUSIONS

Cytoreductive surgery and HITHOC with cisplatin and adriamycin is feasible in patients with pleural thymoma metastases and early-stage MPM, and is associated with acceptable morbidity rates. Early data on locoregional disease control are encouraging, and a phase II study will be conducted.

Malignant pleural mesothelioma

Malignant pleural mesothelioma remains a difficult tumor to treat, much less cure. Currently, the best chance for long-term survival lies with early diagnosis and aggressive surgical extirpation, but given the typically long delay between the onset of symptoms and diagnosis, this is only possible with a high index of suspicion and an aggressive diagnosis workup. Early referral to a tertiary center experienced in the treatment of MPM may be important for several reasons: (1) decreased risk of tumor spread along multiple thoracenesis/biopsy tracts, (2) the availability of specialized pathologic assays for definitive diagnosis, (3) the availability of critical staging modalities (aggressive mediastinoscopy +/- thoracoscopy, MRI scans performed according to specific mesothelioma protocols, and perhaps PET scans), (4) surgical experience with pleurectomy/decortication and/or extrapleural pneumonectomy, that may decrease morbidity and mortality, and (5) the availability of novel adjuvant protocols. Single-modality therapy is unlikely to result in long-term survival. Aggressive surgery is required for optimal debulking, and extrapleural pneumonectomy may offer better local control compared with pleurectomy/ecortication. Delivery of optimal radiation schedules, which may involve large fractions as well as large total doses, is limited by the presence of nearby dose-limiting structures. Current chemotherapy is severely lacking in producing objective responses and improved survival although gemcitabine and IL-2 may be active agents to be combined with radiation and/or other agents. Hyperthermia, photodynamic therapy, intracavitary therapy, and gene therapy are all relatively new techniques under active investigation that should be supported by enrollment in on-going protocols. Predictably, many of these techniques provide greater benefit when used in the setting of adjuvant protocols or minimal residual disease, emphasizing the importance of multimodality therapy.

Management of malignant pleural mesothelioma: a critical review

Malignant mesothelioma remains a uniformly fatal disease and best supportive care continues to be the standard treatment. Neither chemotherapy nor surgery has been shown to prolong survival. Radiotherapy is not curative but is useful for prophylaxis against needle-track metastases and for symptom palliation. Combinations of therapies have been tried but most studies were uncontrolled and selection bias makes the results impossible to interpret. The combination of extrapleural pneumonectomy, chemotherapy, and radiotherapy attracted much interest, but the subsequent results were disappointing in a highly selected group of patients. Randomized controlled trials are desperately needed to provide definitive information on experimental treatments. It is also important to develop better measures of disease response and to assess quality of life issues in clinical trials. If patients are to receive therapies other than palliation, they should only do so in the setting of randomized controlled trials under approved protocols.

Advances in the treatment of malignant pleural mesothelioma

Malignant pleural mesothelioma is a neoplasm that is commonly fatal and for which there are no widely accepted curative approaches. Mesothelioma is unresponsive to most chemotherapy and radiotherapy regimens, and it typically recurs even after the most aggressive attempts at surgical resection. Multimodality approaches have been of some benefit in prolonging survival of very highly selected subgroups of patients, but they have had a relatively small impact on the majority of the patients diagnosed with this disease. As the incidence of pleural mesothelioma peaks in the United States and Europe over the next 10 to 20 years, new therapeutic measures will be necessary. This review will discuss the roles of chemotherapy, radiotherapy, surgery, and combined modality approaches in the treatment of pleural mesothelioma, as well as scientific advances made in the past decade that have led to the development of experimental techniques, such as photodynamic therapy, immunotherapy, and gene therapy, that are currently undergoing human clinical trials. These promising new avenues may modify the therapeutic nihilism that is rampant among clinicians dealing with mesothelioma.

Pleural space perfusion with cisplatin in the multimodality treatment of malignant mesothelioma: a feasibility and pharmacokinetic study

INTRODUCTION

Malignant pleural mesothelioma is an ideal model for testing new locoregional multimodality approaches because of its aggressive local behavior.

METHODS

This study was planned to investigate the feasibility, safety, and pharmacokinetics of a multimodality therapy including an operation, pleural space perfusion (60 minutes) with cisplatin (100 mg/m2), hyperthermia (41. 5 degrees C), and postoperative radiotherapy (55 Gy to chest wall incisions). The effects of the extent of resection and perfusion temperature on cisplatin pharmacokinetics were evaluated. Ten patients with epithelial or mixed, stage I or II, malignant pleural mesothelioma underwent the following procedures: group A (3 patients), pleurectomy/decortication and normothermic pleural space antineoplastic perfusion; group B (3 patients), pleurectomy/decortication and hyperthermic perfusion; and group C (4 patients), pleuropneumonectomy and hyperthermic perfusion. Operations were selectively applied depending on tumor extent. Platinum levels were serially measured by atomic absorption in systemic blood, perfusate, lung, and endothoracic fascia.

RESULTS

The overall procedure was completed in every case, without any death or toxicity. No lung damage was demonstrated after treatment. Major complications included 1 wound infection and 1 diaphragmatic prosthesis displacement. The mean peak platinum plasma levels were reached within 45 to 60 minutes after perfusion was started. Systemic drug concentrations were greater after pleurectomy/decortication than after pleuropneumonectomy (P =.006). The local tissue/perfusate ratio of platinum concentrations tended to be higher after hyperthermic perfusion rather than normothermic perfusion.

CONCLUSION

This multimodality approach is feasible, pharmacokinetically advantageous, and safe enough to undergo further clinical investigations.