Predicting survival in malignant mesothelioma

Our plain-English summary of Predicting survival in malignant mesothelioma, by A.W. Musk, N. Olsen, H. Alfonso, et al (The European Respiratory Journal, 2011).

The study

• Authors: A.W. Musk, N. Olsen, H. Alfonso, A. Reid, R. Mina, P. Franklin, J. Sleith, N. Hammond, T. Threlfall, K.B. Shilkin, N.H. de Klerk
• Journal: The European Respiratory Journal
• Published: 2011;38(6):1420-4
• Cited by: 103 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Malignant mesothelioma (MM) of the pleura or peritoneum is a universally fatal disease attracting an increasing range of medical interventions and escalating healthcare costs. Changes in survival and the factors affecting survival of all patients ever diagnosed with MM in Western Australia over the past five decades and confirmed by the Western Australian Mesothelioma Registry to December 2005 were examined. Sex, age, date and method of diagnosis, site of disease and histological type were recorded. Date of onset of symptoms and performance status were obtained from clinical notes for a sample of cases. Cox regression was used to examine the association of the clinical variables and the 10-yr periods of disease onset with survival after diagnosis. Survival was inversely related to age, being worse for males (hazard ratio (HR) 1.4, 95% CI 1.2-1.6), and those with peritoneal mesothelioma (HR 1.4, 95% CI 1.1-1.7). Patients with sarcomatoid histology had worse prognosis than patients with epithelioid and biphasic histological subtypes. Survival improved after the 1970s and has made incremental improvements since then. Median (interquartile range) survival by decade, from 1960 until 2005, was 64 (0-198), 177 (48-350), 221 (97-504), 238 (108-502) and 301 (134-611) days; ~4 weeks of this apparent improvement can be attributed to earlier diagnosis. With increasing resources and treatment costs for MM over the past 40 yrs, there have been modest improvements in survival but no complete remissions.

In plain English

The authors used the Western Australian Mesothelioma Registry to study survival after diagnosis of malignant mesothelioma of the pleura or peritoneum. It included 1,362 cases diagnosed from 1962 to 2005 (1,258 pleural, 102 peritoneal), including former Wittenoom asbestos mine and mill workers, Wittenoom residents, and people with other occupational or residential exposure. Overall median survival was 241 days. Median survival rose from 64 days for the 1960s (8 cases) to 301 days for 2000 to 2005, although the Cox regression hazard ratios for later decades were not statistically significant. Longer survival was associated with female sex (hazard ratio 0.75, 95% CI 0.63 to 0.89), younger age, epithelioid histology and better performance status. Sarcomatoid histology (hazard ratio 1.81, 95% CI 1.48 to 2.22) and peritoneal disease (1.53, 95% CI 1.21 to 1.94) were associated with shorter survival. Survival did not differ significantly between exposure groups. The authors also built a survival prediction equation. They concluded that survival had improved only modestly over 40 years, with median survival still under one year, and that primary prevention remains the most urgent priority. The registry had no treatment information.

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: Population-based registry study of survival, analysed by Cox regression, with a Weibull model used to build a survival prediction equation
• Who was studied: All 1,362 confirmed cases of malignant mesothelioma on the Western Australian Mesothelioma Registry diagnosed between 1962 and 2005 (1,258 pleural and 102 peritoneal). Symptom-onset dates and performance status came from clinical records for a subset only.
• Exposure: Asbestos exposure categories recorded by the registry: 260 Wittenoom asbestos mine and mill workers, 56 Wittenoom town residents, 760 with other occupational exposure, 87 with residential exposure and 199 with undetermined exposure. 64 (4.7%) had no known exposure. The article describes Wittenoom as a former crocidolite mining town. The study itself analysed survival, not exposure dose.
• Main results:
  • Overall median survival for all 1,362 cases was 241 days (interquartile range 108 to 515)
  • Median survival by decade of diagnosis was 64, 177, 221, 238 and 301 days for the 1960s, 1970s, 1980s, 1990s and 2000 to 2005. The 1960s figure is based on only 8 cases.
  • In the Cox regression, the hazard ratios for the later decades were not statistically significant: for the 2000s, HR 0.41 (95% CI 0.15 to 1.09), p = 0.08
  • Females had longer survival than males: HR 0.75 (95% CI 0.63 to 0.89), p = 0.001. Median survival was 323 days for 181 females and 235 days for 1,181 males.
  • Peritoneal mesothelioma had worse survival than pleural: HR 1.53 (95% CI 1.21 to 1.94). Median survival was 134 days for 102 peritoneal cases and 256 days for 1,258 pleural cases.
  • Sarcomatoid histology was associated with shorter survival: HR 1.81 (95% CI 1.48 to 2.22). Median survival was 113 days for sarcomatoid, 221 days for biphasic and 340 days for epithelioid cases.
  • Younger patients survived longer: median survival ranged from 362 days for those diagnosed before age 50 to 147 days for those diagnosed at 75 or older
  • In the subset with recorded performance status, patients with ECOG performance status greater than 1 had a hazard ratio of 3.4 (95% CI 1.4 to 8.7)
  • There were no significant differences in survival (p = 0.25) between exposure groups (Wittenoom, other occupational, residential, none and unknown)
  • In the reviewed subset, time from presentation to diagnosis did not improve, but time from symptom onset to diagnosis fell from 63 days (1971 to 1979) to 32 days (2000 to 2005)
• The authors' conclusion: The authors concluded that, despite increasing resources and treatment costs, survival has improved only modestly over the past 40 years, with overall median survival still under one year. They considered the improvement probably due to earlier presentation and diagnosis and improved treatment, and they concluded that primary prevention remains the most urgent priority.
• Limitations the authors state:
  • The registry had no access to treatment information

Mines named here

Asbestos mines this study is about. Each mine's page says who ran it, when it worked, and what it produced.

• Wittenoom, Western Australia

All asbestos mines

Topics

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

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Pleura, Peritoneum, Mesothelioma, Performance Status, Hazard Ratio, Peritoneal Mesothelioma, Sarcomatoid.

Related studies

• Predicting survival in mesothelioma — A.W. Musk (2012)
• Patterns in the incidence, mortality and survival of malignant pleural and peritoneal mesothelioma, New South Wales, 1972-2009 — M.J. Soeberg, N. Creighton, et al. (2016)
• Asbestos exposure and histological subtype of malignant mesothelioma — P. Franklin, H. Alfonso, et al. (2016)
• Malignant pleural and peritoneal mesotheliomas in former miners and millers of crocidolite at Wittenoom, Western Australia — G. Berry, N.H. de Klerk, et al. (2004)
• Malignant mesotheliomas in former miners and millers of crocidolite at Wittenoom (Western Australia) after more than 50 years follow-up — G. Berry, A. Reid, et al. (2012)
• Factors influencing long-term survival in mesothelioma patients--results of the German mesothelioma register — V. Neumann, A. Rütten, et al. (2004)

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