Chemotherapy Induced Pathologic Complete Response in Malignant Pleural Mesothelioma: A Review and Case Report

The timing of chemotherapy in the management plan for medically operable early-stage malignant pleural mesothelioma

Introduction: Trimodality therapy (including surgery, chemotherapy and radiation therapy) represents an important management approach of early-stage malignant pleural mesothelioma (MPM). The oncological value, as well as the proper sequence of the three modalities, is still under investigations. Areas Covered: The article covers the timing of chemotherapy in the management plan with either a neoadjuvant approach or adjuvant approach. It evaluates also how to select patients for induction chemotherapy and how to assess the response to treatment. Expert Opinion: Management of patients with early-stage MPM must be completed in a multidisciplinary team in tertiary centers. Availability of newer prognostic and response assessment tools should facilitate the use of induction chemotherapy as well as the selection of patients who might benefit from radical surgery.

Micro-RNA149 confers taxane resistance to malignant mesothelioma cells via regulation of P-glycoprotein expression

Multidrug resistance (MDR) represents a major hindrance to the efficacy of cancer chemotherapeutics. While surgical resection, radiation, and chemotherapy can be used to reduce tumor size, the subsequent appearance of drug resistant cells is a frequent problem. One of the main contributors to the development of MDR is increased expression of multi-drug resistant protein 1 (MDR1), also known as P-glycoprotein (P-gp). P-gp is a membrane-associated efflux pump that can efficiently remove internalized taxane-base chemotherapeutics thus preventing drug accumulation and maintaining cellular viability. Consequently, investigation into the molecular mechanisms responsible for regulation of P-gp expression is necessary to facilitate treatment of MDR tumors. Using molecular and biochemical approaches, we identified that the micro-RNA, miRNA149, contributes to the development of MDR within malignant mesothelioma cells by regulating the expression of MDR1.

Pathological complete response in malignant pleural mesothelioma patients following induction chemotherapy: Predictive factors and outcomes

A small proportion of patients with malignant pleural mesothelioma (MPM) achieve pathological complete response (CR) following treatment with current practice induction chemotherapy. Our analysis of 58 patients with MPM treated with platinum-based chemotherapy showed 4 patients (7%) attained pathological CR at subsequent extrapleural pneumonectomy (EPP). Patient and tumour factors such as age, gender, smoking habit, histological subtype, and clinical stage were not found to be associated with pathological CR. Patients with pathological CR had longer disease-free survival (29.2 vs. 13.8 months; p=0.08) and overall survival (76.4 vs. 23.4 months; p=0.06) but this did not reach statistical significance. Our study suggests that patients who achieve pathological CR after chemotherapy may have improved survival in MPM.

Induction chemotherapy vs post-operative adjuvant therapy for malignant pleural mesothelioma

INTRODUCTION

Malignant pleural mesothelioma (MPM) is an aggressive neoplasia. Multidisciplinary treatments, including the association of induction and/or adjuvant therapeutic regimens with surgery, have been reported to give encouraging results. Current therapeutic options are not well standardized yet, especially regarding the best association between surgery and medical treatments. The present review aims to assess safety, efficacy and outcomes of different therapies for MPM. Areas covered: This article focuses on the multimodality treatment of mesothelioma. A systematic review was performed by using electronic databases to identify studies that considered induction and adjuvant approaches in MPM therapy in a multidisciplinary setting, including surgery. Endpoints included overall survival, disease free survival, disease recurrence, and complications. Expert commentary: This systematic review offers a comprehensive view of current multidisciplinary therapeutic strategies for MPM, suggesting that multimodality therapy offers acceptable outcomes with better results reported for trimodality approaches. Individualization of care for each patient is fundamental in choosing the most appropriate treatment. The growing complexity of treatment protocols mandates that MPM patients be referred to specialized Centers, in which every component of the interdisciplinary team can provide the necessary expertise and quality of care.

Induction Therapy for Mesothelioma

One particular approach of multimodality treatment for mesothelioma is induction therapy followed by surgery. Among its several advantages, the most important is downstaging of the tumor into a resectable stage, although morbidity and mortality might be increased. In this article we review the principles and outcome of different modalities for induction treatment of mesothelioma.

Response evaluation in mesothelioma: Beyond RECIST

Malignant pleural mesothelioma (MPM) typically demonstrates a non-spherical growth pattern, so it is often difficult to accurately categorize change in tumour burden using size-based tumour response criteria (e.g., WHO (World Health Organisation), RECIST (Response Evaluation Criteria in Solid Tumours) and modified RECIST). Functional imaging techniques are applied to derive quantitative measurements of tumours, which reflect particular aspects of the tumour pathophysiology. By quantifying how these measurements change with treatment, it is possible to observe treatment effects. In this review, we survey the existing roles of CT and MRI for the management of MPM, including the currently applied size measurement criteria for the assessment of treatment response. New functional imaging techniques, such as positron emission tomography (PET), diffusion-weighted MRI (DWI) and dynamic contrast-enhanced MRI (DCE-MRI) that may potentially improve the assessment of treatment response will be highlighted and discussed.

Management of malignant pleural mesothelioma-The European experience

Management of malignant pleural mesothelioma (MPM) remains a clinical challenge and the incidence of the disease will continue to increase worldwide. Several aspects of mesothelioma treatment are discussed controversially, in particular, regarding extent and best type of surgery, radiotherapy, and the role of neoadjuvant or adjuvant treatment. However, best survival data is reported from groups using multimodality treatment including macroscopic complete resection (MCR) achieved by either extrapleural pneumonectomy (EPP) or (extended) pleurectomy/decortication for patients qualifying from the tumor biology, stage, and patient's performance status and comorbidities. Several aspects have to be considered during surgery but morbidity and mortality have been reduced at experienced centres. The final analysis of extended selection algorithms is pending.

Adaptation of a chemosensitivity assay to accurately assess pemetrexed in ex vivo cultures of lung cancer

PURPOSE

Pemetrexed is the only FDA approved treatment for mesothelioma and is a second line agent for treatment of non-small cell lung carcinoma (NSCLC). Pemetrexed is inhibited by folate and its analogs, which are components of many culture media, making it challenging to study pemetrexed in vitro. In order to accurately evaluate pemetrexed's effects in vitro, the protocol for a standard chemosensitivity assay, the ChemoFx drug response marker, had to be modified.

EXPERIMENTAL DESIGN

Novel rinse and media change steps were assessed and then added to the assay protocol in order to observe pemetrexed activity. The intraday and interday stability of pemetrexed were also established under the adapted protocol. Then, the modified protocol was used to examine pemetrexed in 65 ex vivo lung cancer specimens.

RESULTS

Substituting 5% RPMI + EGF for BEGM allowed pemetrexed to exert its anticancer activity in the ChemoFx DRM. ChemoFx classified 6.2% of the lung specimens as responsive, 9.2% as intermediate responsive and 84.6% as non-responsive to pemetrexed.

CONCLUSIONS

Adapting the ChemoFx protocol allowed for the accurate evaluation of pemetrexed anticancer activity in ex vivo lung specimens. ChemoFx evaluation may provide an indication of a patient's clinical response to the drug prior to pemetrexed treatment. Having this information when treatment options are being considered could avoid wasted time, unnecessary costs and needless side effects that are the result of an inappropriate chemotherapy regimen.

A phase II trial of low-dose gemcitabine in a prolonged infusion and cisplatin for malignant pleural mesothelioma

After a favorable experience with gemcitabine at a low dose in a prolonged infusion in combination with cisplatin for advanced non-small-cell lung cancer, here, we present the results from a phase II trial for patients with malignant pleural mesothelioma. Eligible patients had biopsy-proven malignant pleural mesothelioma, were chemo-naive, Eastern Cooperative Oncology Group performance status 0-2, had normal hematopoietic liver and renal function, and gave informed consent. Treatment consisted of gemcitabine 250 mg/m in a 6-h infusion on days 1 and 8 and cisplatin at 75 mg/m on day 2 of a 3-week cycle for four cycles, followed by two additional cycles without cisplatin. Seventy-eight patients (58 men, 20 women; age 33-82 years, median 58) were recruited into the trial. The histologic types were as follows: epitheloid 56 (71.8%); four sarcomatoid (5.1%); mixed 15 (19.2%); and mesothelioma, three not otherwise specified (3.8%). Grades 3-4 toxicity included two (2.6%) patients with anemia, 18 (23.1%) with neutropenia, and one with nausea/vomiting. Reversible thrombocytosis with platelets over 1000-10/l was recorded in 10 (12.8%) patients and grade 2 alopecia in 60 (76.9%). Four (5.1%) patients showed a complete response and 35 (44.9%) showed a partial response with a response rate of 39/78 (50%). Minimal response or stable disease was seen in 35 (44.9%), whereas only four (5.1%) patients progressed during treatment. Most patients reported symptomatic improvement with a higher or a stable quality of life score in 70 (89.7%) cases. The median progression-free survival was 8.0 months (confidence interval 6.9-9.0). The median overall survival was 17.0 months (confidence interval 14.7-19.2). One-year, two-year, and three-year survival rates were 67.3, 32.7, and 19.8%, respectively. Epitheloid histological type was the only statistically significant favorable prognostic factor for progression-free survival and overall survival. Because of the acceptable toxicity, remarkable activity, and reasonable cost, this treatment should be further explored.