MARS: a sense of perspective and an inconvenient truth

Our plain-English summary of MARS: a sense of perspective and an inconvenient truth, by T. Treasure, M. Utley, K. O'Byrne (Journal of Thoracic Oncology, 2013).

The study

• Authors: T. Treasure, M. Utley, K. O'Byrne
• Journal: Journal of Thoracic Oncology
• Published: 2013;8(5):e48-9
• Type of article: Letter, Comment
• Cited by: 10 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Summary of the article

In this letter to the editor, the authors responded to comments by Kindler and by Rusch et al., published in the November issue of the Journal of Thoracic Oncology, about the Mesothelioma and Radical Surgery (MARS) trial of extrapleural pneumonectomy (EPP) for malignant pleural mesothelioma. They stated that MARS, which reported 50 randomized patients, was funded by Cancer Research UK as a feasibility study. A full trial with 80% power to detect a survival advantage from EPP had been estimated to need 670 patients. They argued that 50 patients were enough to raise serious concern that EPP might shorten life and reduce its quality. On operative mortality, they reported EPP mortality in MARS of 2 of 19 (10.5%; exact 95% confidence limits 1.3%-33.1%). They said this lay within the 0% to 11.8% range of 30-day mortality in a systematic review of 34 studies including 2320 patients. Median survival in the EPP arm was 14.4 months from randomization, which they said was in line with EPP cohorts published from 2007 to 2009 (10 to 14 months). Patients randomized to no surgery had a median survival of 19.5 months. On feasibility, MARS registered 112 patients in 2005-2008, and 57 consented to randomization. The authors concluded that effort should go into obtaining high-quality evidence, for example on lung-sparing surgery and quality of life.

PubMed has no abstract for this study, and the article doesn't print one. We wrote this summary from the full article with the help of AI. It is not the authors' wording.

In plain English

This is a letter to the editor, not a new study. The authors wrote to answer criticisms of the Mesothelioma and Radical Surgery (MARS) trial raised by other authors. MARS compared extrapleural pneumonectomy (EPP), a major operation, with no EPP in patients with malignant pleural mesothelioma. The authors acknowledged that MARS randomized just 50 patients, a small number. They explained that it was funded as a 50-patient study to test feasibility, and that a full trial had been estimated to need 670 patients. They reported EPP mortality in MARS of 2 of 19 (10.5%; exact 95% confidence limits 1.3% to 33.1%). They said this lay within the 0% to 11.8% range of 30-day mortality found in a systematic review of other studies. Median survival was 14.4 months from randomization in the EPP arm and 19.5 months among patients randomized not to have surgery. The authors concluded that 50 patients were enough to raise a serious concern that surgery might shorten life and reduce its quality. They called for high-quality evidence on lung-sparing surgery. The letter does not study asbestos exposure.

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: Letter to the editor (commentary) defending a previously published randomized feasibility trial; no new data collection
• Who was studied: Patients with malignant pleural mesothelioma in the MARS trial: 50 randomized patients, from 112 registered in 2005 to 2008
• Exposure: Not an asbestos exposure study; the letter concerns extrapleural pneumonectomy (EPP) surgery versus no EPP for malignant pleural mesothelioma
• Main results:
  • MARS was funded as a 50-patient feasibility study; the sample size estimated for a definitive randomized study was 670 patients
  • EPP mortality in MARS was 2 of 19 (10.5%; exact 95% confidence limits 1.3% to 33.1%). The authors compared this with a systematic review of 34 other studies (2320 patients) in which 30-day mortality ranged from 0% to 11.8%
  • Median survival in the MARS EPP arm was 14.4 months from randomization
  • Among MARS patients considered suitable for EPP but randomized not to have surgery, median survival was 19.5 months
  • Recruitment: 112 patients registered over 3 years (2005 to 2008); 18 withdrew of their own volition, and after clinical exclusions 57 gave further consent to be randomized
• The authors' conclusion: The authors concluded that 50 patients were enough to raise a serious concern that the surgical part of multimodal treatment might shorten life and reduce its quality. They called for high-quality evidence, for example on lung-sparing surgery and quality of life.
• Limitations the authors state:
  • The authors acknowledged that MARS randomized only 50 patients, a small number

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: Mesothelioma, Extrapleural Pneumonectomy (EPP), Pleural Mesothelioma, Systematic Review, Median Survival, Quality of Life.

Related studies

• MARS: a sense of perspective and an inconvenient truth — V.W. Rusch, H.L. Kindler (2013)
• Extra-pleural pneumonectomy versus no extra-pleural pneumonectomy for patients with malignant pleural mesothelioma: clinical outcomes of the Mesothelioma and Radical Surgery (MARS) randomised feasibility study — T. Treasure, L. Lang-Lazdunski, et al. (2011)
• Surgery for mesothelioma: MARS landing and future missions — T. Treasure (2010)
• Canada, chrysotile, and the search for truth — T. Ogden (2008)
• Common sense in the environment — (1991)
• The MARS feasibility trial: conclusions not supported by data — W. Weder, R.A. Stahel, et al. (2011)

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