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

Our plain-English summary of Pathological complete response in malignant pleural mesothelioma patients following induction chemotherapy: Predictive factors and outcomes, by B. Lau, S. Kumar, T. Yan, et al (Lung Cancer, 2017).

The study

• Authors: B. Lau, S. Kumar, T. Yan, J. Burn, C. Kennedy, J. McLean, M. Boyer, B. McCaughan, S. Kao
• Journal: Lung Cancer
• Published: 2017;111:75-78
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

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.

Copyright © 2017 Elsevier B.V. All rights reserved.

In plain English

This short communication retrospectively reviewed 58 consecutive patients with malignant pleural mesothelioma at two Sydney hospitals, January 2003 to July 2015. All had platinum-based induction chemotherapy, mostly cisplatin with pemetrexed, then extrapleural pneumonectomy, removing the pleura, lung, pericardium and diaphragm. Four (7%) had a pathological complete response: no cancer cells in the removed tissue. All four had the epithelioid subtype. No pretreatment factor examined, including age, gender, smoking and stage, was significantly associated with complete response. Median disease-free survival was 29.2 months (95% CI not reached) with complete response versus 13.8 months (95% CI 8.3 to 19.3) without (p=0.08). Median overall survival was 76.4 months (95% CI 0 to 163.4) versus 23.4 months (95% CI 19.7 to 27.1) (p=0.06). Neither difference was statistically significant. After adjusting for gender, subtype and stage, patients without complete response had worse disease-free survival (hazard ratio 4.51, 95% CI 1.04 to 19.65) and overall survival (hazard ratio 5.13, 95% CI 1.17 to 22.57). The authors concluded that pathological complete response may be a good prognostic indicator. They noted that small numbers and the retrospective design may limit the findings.

We wrote this plain-English summary from the full article with the help of AI, and a second AI model checked each sentence against the article. It is not the authors' wording; the abstract and the article are their own account.

What the study did and found

• Design: Retrospective review of consecutive patients (short communication)
• Who was studied: 58 patients with pathologically confirmed malignant pleural mesothelioma who had induction chemotherapy followed by extrapleural pneumonectomy at Royal Prince Alfred and Strathfield Private Hospitals, Sydney, Australia, January 2003 to July 2015. 46 male (79%) and 12 female (21%), median age 63 (range 32 to 90). 52 (90%) had the epithelioid subtype and 6 (10%) the biphasic subtype.
• Exposure: This was a treatment study, not a study of asbestos exposure. Patients received platinum-based induction chemotherapy before extrapleural pneumonectomy: cisplatin/pemetrexed 42 (72%), carboplatin/pemetrexed 14 (24%), carboplatin/vinorelbine 1 (2%), carboplatin/paclitaxel 1 (2%). The median was 3 cycles (range 1 to 9), and 38 (66%) had adjuvant radiotherapy. The patients' asbestos exposure was not reported.
• Main results:
  • 4 of 58 patients (7%) had a pathological complete response in the surgically resected tissue.
  • No pretreatment patient or tumour factor examined was significantly associated with pathological complete response. All four complete responders had the epithelioid subtype.
  • Median disease-free survival was 29.2 months (95% CI not reached) in patients with pathological complete response versus 13.8 months (95% CI 8.3 to 19.3) in those without; p=0.08.
  • Median overall survival was 76.4 months (95% CI 0 to 163.4) in patients with pathological complete response versus 23.4 months (95% CI 19.7 to 27.1) in those without; p=0.06.
  • In Cox regression adjusting for gender, histological subtype and clinical stage, patients without pathological complete response, compared with those with it, had a disease-free survival hazard ratio of 4.51 (95% CI 1.04 to 19.65; p=0.05) and an overall survival hazard ratio of 5.13 (95% CI 1.17 to 22.57; p=0.03).
  • Across all 58 patients, median disease-free survival was 15.1 months (95% CI 6.9 to 23.3) and median overall survival was 24.4 months (95% CI 20.0 to 28.9). 43 deaths (74.1%) occurred during the study.
• The authors' conclusion: The authors concluded that pathological complete response to chemotherapy may be a good prognostic indicator in malignant pleural mesothelioma. They did not find clinical factors that could predict it.
• Limitations the authors state:
  • The small number of patients, and the very small number with pathological complete response, may limit the power of the statistical analyses.
  • The retrospective design and its inherent biases may limit interpretation of the findings.

Topics

The National Library of Medicine indexes this study under subjects our site covers: Lung cancer, Mesothelioma.

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Chemotherapy, Extrapleural Pneumonectomy (EPP), Habit, Histological Subtype, Disease-Free Survival, Overall Survival, Statistical Significance.

Related studies

• A pathological complete response in malignant pleural mesothelioma after combination chemotherapy with Carboplatin and pemetrexed — S.C. Kao, B. McCaughan, et al. (2010)
• Folylpoly-glutamate synthetase expression is associated with tumor response and outcome from pemetrexed-based chemotherapy in malignant pleural mesothelioma — D.C. Christoph, B.R. Asuncion, et al. (2012)
• PI3K/mTOR signaling in mesothelioma patients treated with induction chemotherapy followed by extrapleural pneumonectomy — B.K. Bitanihirwe, M. Meerang, et al. (2014)
• Soluble mesothelin, megakaryocyte potentiating factor, and osteopontin as markers of patient response and outcome in mesothelioma — K. Hollevoet, K. Nackaerts, et al. (2011)
• ERCC1, MLH1, MSH2, MSH6, and βIII-tubulin: resistance proteins associated with response and outcome to platinum-based chemotherapy in malignant pleural mesothelioma — S. Ting, F.D. Mairinger, et al. (2013)
• A feasibility study of induction pemetrexed plus cisplatin followed by pleurectomy/decortication aimed at macroscopic complete resection for malignant pleural mesothelioma — M. Shimokawa, S. Hasegawa, et al. (2013)

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