Current concepts in chemotherapy for malignant pleural mesothelioma

Physicochemical and pharmacokinetic properties of polymeric films loaded with cisplatin for the treatment of malignant pleural mesothelioma

Background

Malignant mesothelioma is an invasive neoplasm arising from mesothelial surfaces of the pleural and peritoneal cavities. Mesothelioma treatment is unsatisfactory and recurrence is common. Here an innovative locoregional treatment for malignant pleural mesothelioma is presented.

Methods

Chitosan- and hyaluronate-based films were loaded with 0.5% and 4% w/w cisplatin and were studied for their physicochemical, mechanical and drug release characteristics. The performance of the drug delivery systems was assessed in vitro on A549 cells and on an orthotopic model of MPM recurrence in rats.

Results

Polysaccharide films produced were thin, flexible and resistant. Cisplatin was completely released from hyaluronic acid films within 96 hours, while drug release was found to be much more prolonged with chitosan films. The drug released from hyaluronate films was effective against A549 cell line, while for chitosan films the release was too slow to produce cytotoxicity. Similarly, cisplatin-loaded chitosan films in vivo released minimal quantities of cisplatin and induced inflammation and foreign body reaction. Cisplatin-loaded hyaluronate acid films on the contrary were able to prevent tumor recurrence. The cisplatin-loaded hyaluronate films provided higher C_max and AUC compared to a solution of cisplatin administered intrapleurally, but did not show any sign of treatment related toxicity.

Conclusions

Hyaluronate-based films appear as an optimal platform for the development of drug delivery systems suitable for the loco-regional post-surgical treatment of lung malignancies.

Thymidylate synthase protein expression levels remain stable during paclitaxel and carboplatin treatment in non-small cell lung cancer

BACKGROUND

Thymidylate synthase (TS) is a potential predictive marker for efficacy of treatment with pemetrexed. The current study aimed at investigating whether TS expression changes during non-pemetrexed chemotherapy of non-small cell lung cancer (NSCLC), thus making rebiopsy necessary for deciding on pemetrexed second-line treatment.

MATERIALS AND METHODS

TS immunohistochemístry was performed on biopsies and available resection specimens from 65 NSCLC patients stage T1-3N0-2 treated with preoperative carboplatin and paclitaxel [neoadjuvant chemotherapy (NAC)-group] and from 53 NSCLC patients stage T1-4N0-1 treated with surgery without preceding chemotherapy [operation (OP)-group] that served as controls. The diagnostic biopsies and subsequent resection samples were compared in order to evaluate for change in TS expression in groups treated with and without preoperative chemotherapy.

RESULTS

No statistically significant change in TS expression was observed between diagnostic biopsies and subsequent surgical resections of primary tumors in either the OP-group (p = 0.186) or the NAC-group (p = 0.542). Primary tumors were discordant between diagnostic biopsies and resection specimens when TS expression was dichotomized into high (H score ≥ 150) and low (H score < 150), in 45 and 33% in the OP-group and NAC-group, respectively (p = 0.288). The fraction of tumors which increased (19 vs. 20%; p = 0.900) and decreased (42 vs. 23%; p = 0.095) in TS expression was equal between the OP- and the NAC-group.

CONCLUSION

The discordance observed between paired serial samples likely reflects intratumoral heterogeneity of TS expression and highlights the need of sufficient representative material for TS expression analysis if this biomarker is to be used for treatment selection. TS expression in primary tumors remained unchanged, and new biopsies for deciding on second-line pemetrexed does not seem warranted based on the current results.

A biomarker profile for predicting efficacy of cisplatin-vinorelbine therapy in malignant pleural mesothelioma

PURPOSE

Malignant pleural mesothelioma (MPM) has a dismal prognosis. Treatment results may be improved by biomarker-directed therapy. We investigated the baseline expression and impact on outcome of predictive biomarkers ERCC1, BRCA1, and class III β-tubulin in a cohort of MPM patients treated with cisplatin-vinorelbine. We further explored the possibility of combining markers into a treatment-response profile to increase the predictive power.

METHODS

Formalin-fixed paraffin-embedded tumor specimens from 54 MPM patients included in a phase II trial were evaluated for ERCC1, BRCA1, and class III β-tubulin by immunohistochemistry (IHC). Immunostaining was quantified by an H-score and dichotomized according to upper quartile values. The ERCC1- and class III β-tubulin-status classified patients as treatment resistant (ERCC1 positive + class III β-tubulin positive) or treatment responsive (ERCC1 negative + class III β-tubulin negative). The remaining marker combinations were considered inconclusive.

RESULTS

Fifty patients had tumor tissue available for IHC. Eleven had a responsive profile, and nine had a resistant profile. Thirty patients had an inconclusive profile. Median progression-free survival (PFS) was 6.7 months in the treatment-resistant group, 15.3 months in the treatment-responsive group, and 8.1 months in the inconclusive group (log-rank p = 0.03). Multivariate analysis revealed that treatment-resistant patients had a decreased PFS and overall survival (OS) compared with the treatment-responsive patients (HR 6.45, CI 95 % [2.02-20.64] p = 0.002 and HR 4.64, CI 95 % [1.56-13.79], p = 0.006, respectively). BRCA1 status was associated with neither PFS nor OS.

CONCLUSION

Combined negative ERCC1 and class III β-tubulin immunostaining is associated with significantly prolonged PFS and OS in MPM patients receiving cisplatin-vinorelbine therapy.

Low ERCC1 expression in malignant pleural mesotheliomas treated with cisplatin and vinorelbine predicts prolonged progression-free survival

INTRODUCTION

The relationship between excision repair cross-complementation group 1 (ERCC1) expression and outcome, in patients with malignant pleural mesothelioma (MPM), treated with cisplatin/vinorelbine combination-therapy, was retrospectively evaluated in a patient population from a previously published phase II clinical trial.

METHODS

The study population consisted of 54 inoperable patients with MPM enrolled between 2003 and 2006. ERCC1 expression was evaluated by immunohistochemistry (IHC) on the formalin-fixed paraffin-embedded diagnostic biopsies. The immunoreaction was quantified using an H-score (staining intensity multiplied by a proportion score based on the percentage of stained tumor cells). The cutoff point was chosen as the median H-score in a cohort of non-neoplastic pleural samples from patients with benign thoracic diseases. The tumor samples were separated according to this cutoff point into ERCC1-negative (H-score ≤ median) and ERCC1-positive (H-score > median) cases.

RESULTS

Fifty patients had tumor tissue available for IHC. There were 20 ERCC1-positive and 30 ERCC1-negative tumors. There was a significant correlation between negative ERCC1 status and long progression-free survival (PFS). Median PFS was 10.9 months in the ERCC1-negative group, opposed to 6.7 months in the ERCC1-positive group (p = 0.053). Multivariate Cox regression showed ERCC1 to be the only variable significantly associated with PFS, and ERCC1-positive patients had a significantly shorter time to progression compared with ERCC1-negative patients (hazard ratios, 2.24; 95% confidence interval, 1.16-4.34; p = 0.0163). We found no association between ERCC1 status and overall survival.

CONCLUSION

Our retrospective study in MPM patients treated with cisplatin/vinorelbine suggests that low ERCC1 expression, evaluated by IHC, may predict longer PFS, a result that warrants further validation.

Cisplatin and vinorelbine first-line chemotherapy in non-resectable malignant pleural mesothelioma

The aim was to evaluate the activity of cisplatin and vinorelbine in previously untreated, inoperable patients having histologically verified malignant pleural mesothelioma (MPM), normal organ function, and performance status 0-2. Treatment was vinorelbine 25 mg m(-2) i.v. weekly and cisplatin 100 mg m(-2) i.v. every 4 weeks with hydration and standard prophylactic antiemetic treatment. Patients gave written informed consent. Characteristics of 54 consecutive patients were: males 85%, epithelial subtype 74%, IMIG stages III and IV 35 and 46%, performance status 0, 1, and 2, 26, 69, and 6%, and median age 63 years (31-78 years). CTC grade 3 or 4 toxicity occurred with respect to leukocytopenia (48% of patients, grade 4 in 13%), nausea (13%), neurotoxicity (11%), nephrotoxicity (4%), and other toxicities (9%). There were no toxic deaths. The median number of cycles was four. The fraction of patients alive at 1-, 2-, and 3-years were 61, 31, and 4%, respectively, and median survival and median time to progression were 16.8 months (0.5 to 46.4 +months) and 7.2 months (1.6 to 40.6 + months). There were two CRs and 14 PRs (response rate 29.6%). Cisplatin and intravenous vinorelbine is a highly active regimen in MPM with a response rate and survival comparable to the most active regimens so far reported.