Patterns of care and survival among patients with malignant mesothelioma in the United States

Our plain-English summary of Patterns of care and survival among patients with malignant mesothelioma in the United States, by L. Enewold, E. Sharon, A. Thomas (Lung Cancer, 2017).

The study

• Authors: L. Enewold, E. Sharon, A. Thomas
• Journal: Lung Cancer
• Published: 2017;112:102-108
• Cited by: 19 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: Mesothelioma is a rare malignancy that is associated with poor survival. This study aimed to describe the patterns of care and subsequent survival among malignant mesothelioma patients in the United States, while adjusting for patient demographics and comorbidities.

Methods: A random sample of patients diagnosed with histologically confirmed mesothelioma in 2011, as reported to the National Cancer Institute's Surveillance Epidemiology and End Results program, were included. Logistic regression and Cox proportional hazard regression were utilized to identify factors associated with receipt of therapy and all-cause mortality, respectively, among patients with pleural mesothelioma.

Results: This study included 389 patients with pleural mesothelioma and 53 patients with non-pleural mesothelioma. Almost a third (29.3%) of the pleural patients and 21.5% of the non-pleural patients received no therapy. Additionally, approximately 60% of both patient groups received systemic therapy. Among pleural mesothelioma patients, receipt of therapy was less likely among older patients. Median survival was 9 months among the pleural patients and 18 months among the non-pleural patients. Receipt of either surgery or systemic therapy and particularly the combination of these two modalities was associated with better all-cause survival. Additionally, among pleural mesothelioma patients, younger age and lower socioeconomic status were found to be associated with better all-cause survival. Comorbidity score was not found to be associated with receipt of treatment nor was it independently associated with survival among pleural mesothelioma patients.

Conclusion: These findings indicate the need for efforts to ensure equitable application of currently available therapies to all patients.

Published by Elsevier B.V.

In plain English

This study described treatment and survival of U.S. patients diagnosed with mesothelioma in 2011. It used National Cancer Institute registry data on 442 adults: 389 with pleural and 53 with non-pleural mesothelioma. Among pleural patients, 29.3% received no treatment and 62% received systemic (drug) therapy. Among non-pleural patients, 21.5% received no treatment and 61.6% received systemic therapy. Pleural patients aged 70 or older were less likely than those under 50 to receive surgery or systemic therapy. Median survival was 9 months for pleural patients and 18 months for non-pleural patients. Among pleural patients, surgery and systemic therapy were associated with better survival. Older age, sarcomatoid histology, stage IV disease and living in the highest rather than the lowest socioeconomic fifth of areas were associated with poorer survival. Fewer than 5% of patients joined a clinical trial. The study did not test whether asbestos causes mesothelioma; among pleural patients, recorded asbestos exposure was linked to receiving systemic therapy, but not after adjustment for other factors. The authors cautioned that treated patients may have been healthier. They concluded that available therapies need to be applied equitably.

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 observational study (NCI Patterns of Care study) using SEER cancer registry data, with treatment re-abstracted from hospital records and verified with treating physicians; regression and survival analyses
• Who was studied: 442 adults (20 or older, no prior cancer) diagnosed in 2011 with histologically confirmed mesothelioma and reported to U.S. SEER registries: 389 pleural and 53 non-pleural. All eligible patients were included except in the Greater California registry, where 50 of 143 cases were randomly sampled. Vital status was followed through December 31, 2013.
• Exposure: Not a study of whether asbestos causes mesothelioma. The factors examined were treatments (surgery, radiation, systemic therapy) and patient and hospital characteristics. Recorded asbestos exposure was one of the patient characteristics tested as a factor in receiving treatment and in survival. Pleural patients more often had a history of asbestos exposure than non-pleural patients.
• Main results:
  • Pleural mesothelioma patients: 29.3% received no treatment, 27.1% surgery, 18.4% radiation and 62% systemic therapy (weighted percentages).
  • Non-pleural mesothelioma patients: 21.5% received no treatment, 51.8% surgery, 4.9% radiation and 61.6% systemic therapy.
  • Among pleural patients, those aged 70 or older were less likely than those under 50 to receive surgery (OR 0.15). Stage III patients were more likely than stage I patients to receive surgery (OR 3.72).
  • Among pleural patients, those aged 70 or older were less likely than those under 50 to receive systemic therapy (OR range 0.17 to 0.19).
  • Among pleural patients, recorded asbestos exposure was significantly associated with receiving systemic therapy in bivariate analysis (72.7% of those with recorded exposure vs 47.6% of those without). In the multivariate model the association was not significant: no exposure vs exposure OR 0.83, 95% CI 0.44 to 1.64.
  • Median survival was 18 months for non-pleural patients and 9 months for pleural patients. By the end of 2013, more than 86% of pleural patients and 55% of non-pleural patients had died.
  • Among pleural patients, poorer all-cause survival was associated with age 70 or older vs under 50 (HR range 2.43 to 2.45) and with living in the highest vs lowest socioeconomic quintile (HR 1.78; 95% CI 1.13 to 2.79), in a multivariate model.
  • Among pleural patients, poorer survival was also associated with sarcomatoid vs epithelioid histology (HR 2.58; 95% CI 1.79 to 3.72) and with stage IV vs stage I (HR 1.85; 95% CI 1.13 to 3.04).
  • Among pleural patients, better all-cause survival was associated with systemic therapy (HR range 0.58 to 0.65) and surgery (HR range 0.58 to 0.71). The association for extrapleural pneumonectomy was not statistically significant.
  • Among pleural patients, comorbidity score was not associated with receiving treatment and was not independently associated with survival.
  • 4.6% of pleural patients and 1.6% of non-pleural patients took part in a clinical trial.
• The authors' conclusion: The authors concluded that only a subset of mesothelioma patients receive the benefit of established treatments, and that efforts are needed to ensure available therapies are applied equitably to all patients.
• Limitations the authors state:
  • The study was observational. The link between treatment and better survival may reflect treated patients being healthier at diagnosis, not the treatment itself.
  • Comorbidity was scored from retrospective chart review and may have been misclassified. Performance status and comorbidity severity were unavailable.
  • The small number of non-pleural patients prevented analysis of factors linked to their treatment and survival.
  • The sample size was too small to identify survival differences between individual surgical procedures.
  • Patients were diagnosed in 2011, before newer clinical trial results, so the findings may not reflect current treatment patterns.

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: Malignant Mesothelioma, Mesothelioma, Epidemiology, Pleural Mesothelioma, Systemic Therapy, Median Survival.

Related studies

• Patterns of care for malignant pleural mesothelioma patients compensated by the Dust Diseases Board in New South Wales, Australia — S.C. Kao, S. Clarke, et al. (2013)
• Mesothelioma from asbestos exposures: Epidemiologic patterns and impact in the United States — R.A. Lemen (2016)
• Mesothelioma in the United States: a Surveillance, Epidemiology, and End Results (SEER)-Medicare investigation of treatment patterns and overall survival — J.L. Beebe-Dimmer, J.P. Fryzek, et al. (2016)
• Patterns of care and survival of older patients with malignant pleural mesothelioma — A. Linton, P. Blinman, et al. (2019)
• Malignant Peritoneal Mesothelioma: Patterns of Care and Survival in the Netherlands: A Population-Based Study — N.L. de Boer, J.P. van Kooten, et al. (2019)
• Recent geographic patterns of lung cancer and mesothelioma mortality rates in 49 shipyard counties in the United States, 1970-94 — A. Jemal, D. Grauman, et al. (2000)

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