Changing pattern in malignant mesothelioma survival

Our plain-English summary of Changing pattern in malignant mesothelioma survival, by J. Faig, S. Howard, E.A. Levine, et al (Translational Oncology, 2015).

The study

• Authors: J. Faig, S. Howard, E.A. Levine, G. Casselman, M. Hesdorffer, J.A. Ohar
• Journal: Translational Oncology
• Published: 2015;8(1):35-9
• Cited by: 33 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Unlabelled: Survival for mesothelioma has been shown to be poor, with marginal improvement over time. Recent advances in the understanding of pathophysiology and treatment of mesothelioma may impact therapy to improve survival that may not be evident from available clinical trials that are often small and not randomized. Therapies may affect survival differently based on mesothelioma location (pleural vs peritoneal). Data are conflicting regarding the effect of asbestos exposure on mesothelioma location.

Objectives: We examined survival in a large cohort of mesothelioma subjects analyzed by tumor location and presence and mode of asbestos exposure.

Methods: Data were analyzed from cases (n = 380) diagnosed with mesothelioma from 1992 to 2012. Cases were either drawn from treatment referrals, independent medical evaluation for medical legal purposes, or volunteers who were diagnosed with mesothelioma. Subjects completed an occupational medical questionnaire, personal interview with the examining physician, and physician review of the medical record.

Results: This study reports better survival for mesothelioma than historical reports. Survival for peritoneal mesothelioma was longer than that for pleural mesothelioma (hazard ratio = 0.36, 95% confidence interval = 0.24-0.54, P < .001) after adjusting for gender and age at diagnosis. Non-occupational cases were more likely to be 1) diagnosed with peritoneal mesothelioma, 2) female, 3) exposed, and 4) diagnosed at a younger age and to have a 5) shorter latency compared to occupational cases (P < .001).

Conclusion: Peritoneal mesothelioma was more likely associated with non-occupational exposure, thus emphasizing the importance of exposure history in enhancing early diagnosis and treatment impact.

Copyright © 2014 Neoplasia Press, Inc. Published by Elsevier Inc. All rights reserved.

In plain English

This study examined survival among 380 people with mesothelioma diagnosed between 1992 and 2012. Most (316) were evaluated for medical legal purposes; 21 were surgery referrals and 43 were volunteers. There were 303 pleural and 77 peritoneal cases. After adjusting for age at diagnosis and gender, peritoneal cases survived longer than pleural cases (hazard ratio 0.36, 95% confidence interval 0.24 to 0.54). Median survival was 18.4 months for pleural and 75.7 months for peritoneal cases. Of 284 people exposed to asbestos at work, 27 (9.5%) had peritoneal mesothelioma, compared with 50 of 96 (52.1%) exposed outside work. Median survival was 19.71 months for work-exposed and 53.74 months for non-occupational cases, but the difference was not statistically significant after adjusting for age and gender. The non-occupational group was mostly women, younger at first exposure and at diagnosis. The authors concluded that survival is improving and appears longer than historical reports. They noted that exposure was self-reported, dose and fiber type were not measured, and most subjects were in litigation.

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: Survival analysis of a case series of 380 mesothelioma cases diagnosed from 1992 to 2012, comparing pleural with peritoneal cases and occupational with non-occupational exposure
• Who was studied: 380 people with mesothelioma: 316 seen for independent medical evaluations for medical legal purposes, 21 referred for peritoneal mesothelioma surgery, and 43 volunteers. Diagnoses were documented by pathology reports from laboratories in the United States or Canada (377), by death certificate (2), or by self-report (1).
• Exposure: Asbestos exposure as reported by subjects on a questionnaire and in an interview, classed as occupational (284 subjects) or non-occupational (96 subjects). Occupations of the occupationally exposed were grouped by the Rice classification. Dose and fiber type were not quantified.
• Main results:
  • Of the 380 subjects, 303 had pleural and 77 had peritoneal mesothelioma.
  • After adjusting for age at diagnosis and gender, peritoneal mesothelioma cases had better survival than pleural cases: hazard ratio 0.36, 95% confidence interval 0.24-0.54, p less than .001.
  • Median survival was 18.4 months (range 0.26-142.69) for pleural cases and 75.7 months (range 0.79-326.30) for peritoneal cases.
  • For pleural cases, survival at 1, 3, 5 and 10 years was 73.1%, 22.9%, 12.0% and 4.7%.
  • For peritoneal cases, survival at 1, 3, 5 and 10 years was 91.6%, 73.8%, 65.3% and 39.4%.
  • Of the occupationally exposed subjects, 257 (90.5%) had pleural and 27 (9.5%) had peritoneal mesothelioma.
  • Of the 96 non-occupationally exposed subjects, 46 (47.9%) had pleural and 50 (52.1%) had peritoneal mesothelioma.
  • Median survival was 19.71 months (range 0.26-144.66) for occupationally exposed subjects and 53.74 months (range 2.69-326.30) for non-occupationally exposed subjects.
  • After adjusting for age at diagnosis and gender, survival did not differ significantly between occupational and non-occupational cases (P = .86).
  • Compared with occupational cases, non-occupational cases were younger at first exposure (mean 9.3 vs 18.7 years in Table 1) and at diagnosis (mean 51.9 vs 67.3 years), and had a shorter latency (mean 43.2 vs 49.2 years).
  • Most occupationally exposed cases were men (93% male in Table 1). Most non-occupational cases were women (87.5% female).
  • Of the 77 peritoneal cases, 49 were treated with HIPEC (heated chemotherapy delivered into the abdomen) and cytoreductive surgery, 22 with systemic chemotherapy, and for 6 the treatment was unknown. Treatment was not analyzed as a variable.
  • Among occupationally exposed subjects, laborer/factory worker was the most common occupation for pleural cases and construction worker for peritoneal cases.
  • At the study closing date of 1 March 2012, 92 subjects were alive: 48 (16%) pleural and 44 (57%) peritoneal.
• The authors' conclusion: The authors concluded that survival is improving for peritoneal and, to a lesser extent, pleural mesothelioma and appears longer than in historical reports. They emphasized the importance of taking a thorough occupational and non-occupational exposure history.
• Limitations the authors state:
  • Possible selection bias in the subject pool arising from clinicians' interest in medico-legal issues or in mesothelioma treatment. The authors felt the large number of subjects and confirmed diagnoses were sufficient to offset referral bias.
  • Asbestos exposure was based on patient report, which can be flawed by memory.
  • Dose and fiber type of asbestos were not quantified.
  • Most, if not all, subjects were involved in litigation, which may bias the reporting of how much asbestos exposure they had.
  • Past personal and family history of cancer came from patient report.

Topics

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Mesothelioma, Clinical Trial, Asbestos Exposure, Peritoneal Mesothelioma, Pleural Mesothelioma, Hazard Ratio, confidence interval.

Related studies

• Changing patterns in asbestos-induced lung disease — J. Ohar, D.A. Sterling, et al. (2004)
• Changing patterns of lung cancer in the United States — W.J. Blot, J.F. Fraumeni (1982)
• Changing patterns in asbestos-induced lung disease — P. De Vuyst, P.A. Gevenois, et al. (2004)
• Multimodal therapy of epithelioid pleural mesothelioma: improved survival by changing the surgical treatment approach — L.V. Klotz, H. Hoffmann, et al. (2022)
• Survival patterns for malignant mesothelioma: the SEER experience — R. Spirtas, R.R. Connelly, et al. (1988)
• Patterns of failure, toxicity, and survival after extrapleural pneumonectomy and hemithoracic intensity-modulated radiation therapy for malignant pleural mesothelioma — D.R. Gomez, D.S. Hong, et al. (2013)

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