Geographic and socioeconomic factors in patients with malignant pleural mesothelioma in New South Wales and their impact upon clinical outcomes

Our plain-English summary of Geographic and socioeconomic factors in patients with malignant pleural mesothelioma in New South Wales and their impact upon clinical outcomes, by A. Linton, M. Soeberg, R. Broome, et al (Respirology, 2017).

The study

• Authors: A. Linton, M. Soeberg, R. Broome, S. Kao, N. van Zandwijk
• Journal: Respirology
• Published: 2017;22(5):978-985
• Cited by: 5 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Background And Objective: Whilst the impact of clinicopathological factors on the prognosis of malignant pleural mesothelioma (MPM) is well understood, socioeconomic and geographic factors have received less attention. We analysed the relationship between geographic and socioeconomic factors upon survival and treatment provision in a large series of patients with MPM.

Methods: We assessed MPM patients awarded compensation between 2002 and 2009 with additional MPM incidence data from the New South Wales (NSW) Cancer Registry. The impact of geographic remoteness, distance from oncological multidisciplinary team (MDT) and Index of Relative Socioeconomic Advantage and Disadvantage (IRSAD) upon survival, clinical features and treatment received was analysed.

Results: We identified 910 patients (67% residing in major cities; 92% <50 km from MDT). Median overall survival was 10.0 months. On multivariate analysis, age >70 (hazard ratio (HR) = 1.39), male gender (HR =1.36), non-epithelioid histological subtype (HR = 2.18) and IRSAD status by decreasing quintile (HR = 1.06) were independent prognostic factors. There was no significant advantage for patients residing in major cities (10.6 months vs 8.8 months; P = 0.162) or within 50 km of MDT (10.3 months vs 7.8 months; P = 0.539). Patient's geographic location and distance to MDT did not impact chemotherapy, adjuvant radiotherapy or extrapleural pneumonectomy provision. Socioeconomically disadvantaged patients were significantly less likely to receive chemotherapy (37.4% vs 54.8%; P = 0.001).

Conclusion: This study provides evidence for differences in the treatment and survival according to socioeconomic status for compensated MPM patients in NSW. Further research is warranted to seek additional explanations for the differences noted by comparing the treatments and outcomes of compensated and non-compensated MPM patients in NSW.

© 2017 Asian Pacific Society of Respirology.

In plain English

This retrospective study reviewed records of 910 people with malignant pleural mesothelioma who were awarded compensation for occupational asbestos exposure by the New South Wales Dust Diseases Board between 2002 and 2009. The authors examined whether remoteness of home, distance to a cancer multidisciplinary team, and an area-based socioeconomic index were linked to survival and treatment. Median survival was 10 months. It was 10.6 months in major cities versus 8.8 months in regional or remote areas, and 10.3 versus 7.8 months for patients within versus beyond 50 km of a team. Neither difference was statistically significant. Patients in the most disadvantaged areas had a median survival of 8.4 months, compared with 13.0 months in the most advantaged. In the adjusted analysis, each lower socioeconomic quintile had a hazard ratio of 1.06 (95% CI 1.01–1.12). Chemotherapy was received by 37.4% of the most disadvantaged group versus 54.8% of the most advantaged. The authors concluded that greater socioeconomic disadvantage carried an independent survival detriment. They noted that co-morbidity data were missing and that very few patients lived in remote areas.

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 compensation records linked to death certificates (case series analysis), with comparison to NSW Cancer Registry data
• Who was studied: 910 of 1121 malignant pleural mesothelioma patients awarded compensation by the NSW Dust Diseases Board from 1 January 2002 to 31 December 2009. Patients living or treated outside NSW, patients with peritoneal disease, and patients missing basic data were excluded. 90% were male, and the median age was 72.
• Exposure: Occupational asbestos exposure (fiber types not given). The factors studied were remoteness of residence, distance to an oncology multidisciplinary team, and the area socioeconomic index (IRSAD quintiles).
• Main results:
  • Median survival for all 910 patients was 10 months (range 0–124 months).
  • Median survival was 10.6 months in major cities versus 8.8 months in regional/remote areas. This difference was not statistically significant (P = 0.162).
  • Median survival was 10.3 months for patients within 50 km of a multidisciplinary team versus 7.8 months for those farther away. This difference was not statistically significant (P = 0.539).
  • Median survival was 8.4 months in the lowest (most disadvantaged) socioeconomic quintile versus 13.0 months in the highest (log-rank P = 0.046).
  • On multivariate analysis (n = 812), several factors remained independently linked to survival:
• age 70 or over: HR 1.39 (95% CI 1.20–1.61)
• male sex: HR 1.36 (1.07–1.73)
• non-epithelioid subtype: HR 2.18 (1.87–2.55)
• decreasing IRSAD quintile: HR 1.06 (1.01–1.12; P = 0.021)
  Regional/remote residence was not significant (HR 1.02, 0.85–1.18; P = 0.977).
  • Among patients who received chemotherapy, IRSAD quintile remained a significant independent prognostic factor: HR 1.09 (95% CI 1.01–1.16; P = 0.022).
  • 37.4% of patients in the lowest socioeconomic quintile received chemotherapy, versus 54.8% in the highest (P = 0.001).
  • Geographic location and distance to a multidisciplinary team did not affect provision of chemotherapy, adjuvant radiotherapy or extrapleural pneumonectomy.
  • Palliative radiotherapy was received by 16.0% of regional/remote patients versus 23.9% of major-city patients (P less than 0.01). It was received by 22.1% of patients within 50 km of a team versus 11.8% of those farther away (P = 0.045).
  • The most disadvantaged quintile had a higher proportion of current or ex-smokers than the most advantaged quintile: 67.2% vs 56.6% (P = 0.044).
  • 1,596 patients were notified to the NSW Cancer Registry in 2002–2009. On that basis, the compensated patients living and treated in NSW represented about 57% of all MPM patients.
• The authors' conclusion: The authors concluded that living in areas of greater socioeconomic disadvantage conferred an independent survival detriment, and that fewer of these patients received chemotherapy. In their view, geographic factors did not appear to influence receipt of chemotherapy or surgery. They called for further research comparing compensated and non-compensated patients.
• Limitations the authors state:
  • The study was retrospective, and not all clinical data, such as co-morbidities, were available.
  • Very few patients lived in remote or very remote areas, so the true impact of remoteness is difficult to establish.
  • Only compensated patients were studied. Patterns of care and outcomes for the many non-compensated patients in all districts remain unknown.
  • Patients treated outside NSW were excluded, so most patients near state borders are missing from the series.

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, Prognosis, Cancer Registry, Multidisciplinary Team, Median Overall Survival, Multivariate Analysis, Hazard Ratio, Non-epithelioid.

Related studies

• Factors associated with survival in a large series of patients with malignant pleural mesothelioma in New South Wales — A. Linton, N. Pavlakis, et al. (2014)
• Validation of prognostic factors in malignant pleural mesothelioma: a retrospective analysis of data from patients seeking compensation from the New South Wales Dust Diseases Board — S.C. Kao, J. Vardy, et al. (2013)
• 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)
• Projected mesothelioma incidence in men in New South Wales — M. Clements, G. Berry, et al. (2007)
• Surveillance of Australian workplace Based Respiratory Events (SABRE) in New South Wales — K. Hannaford-Turner, D. Elder, et al. (2010)
• 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)

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