Population based epidemiology and prognosis of mesothelioma in Leeds, UK

Our plain-English summary of Population based epidemiology and prognosis of mesothelioma in Leeds, UK, by A. Chapman, S. Mulrennan, B. Ladd, et al (Thorax, 2008).

The study

• Authors: A. Chapman, S. Mulrennan, B. Ladd, M.F. Muers
• Journal: Thorax
• Published: 2008;63(5):435-9
• Cited by: 61 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Introduction: Malignant mesothelioma is a fatal neoplasm, which is rapidly increasing in incidence throughout Western Europe. To date there have been no studies reporting on the natural history and interventional practices on a comprehensive unselected population, as opposed to reports from referral institutions or compensation claimants. We present a population based study capturing data on all patients with mesothelioma presenting within a defined geographical area over a 4 year period in the UK.

Method: Data of all cases occurring in Leeds with a population of 750 000 were collected retrospectively from 2002 to 2003 and prospectively from 2004 to 2005. All patients' hospital records and the Trust histology database were reviewed, as well as coroner's reports on all patients with a post mortem diagnosis of mesothelioma.

Results: Over the 4 year study period, there were a total of 146 cases in Leeds; 77% were male. Median age was 74 years (range 36-93). Median survival from diagnosis was 8.9 months. 92% and 8% had histological or cytological confirmation, respectively. 85% had documented evidence of definite or probable exposure to asbestos. 110/146 (75%) had symptomatic pleural effusions at presentation. Twice the number of patients (42 vs 17) were managed with surgical rather than bedside pleurodesis and these had a lower recurrence rate (14% vs 47%; p = 0.02). 122 patients had video assisted thoracoscopic surgery/cutting CT biopsies or chest drains. 73/122 (60%) had prophylactic radiotherapy to these sites. There were seven cases (5%) of tract invasion by tumour and six of these had received prophylactic radiotherapy. Median time to seeding was 174 days. 92/146 (63%) had a performance status of 2 or better at diagnosis but only 54/146 were considered fit for chemotherapy. Of these, 28 (52%) declined chemotherapy; the overall uptake of chemotherapy or entry into a trial was 18%. No patient had radical surgery.

Conclusion: This comprehensive population based audit has shown that the median age at presentation of malignant mesothelioma is increasing and baseline performance status and survival is worse than in selected series. 37% of patients were considered suitable for palliative chemotherapy but less than 20% accepted this offer. Thorascopic pleurodesis appears to be associated with fewer recurrences. The role of prophylactic radiotherapy to chest drain and biopsy sites needs reappraisal.

In plain English

This population-based audit sought every tissue- or cell-confirmed case of malignant mesothelioma among the roughly 750,000 people of Leeds, UK, from 2002 to 2005; the authors believed they captured very nearly 100%. Cases before 2004 were reviewed retrospectively, later ones prospectively. There were 146 cases (4.9 per 100,000 per year), median age 74. Of 126 patients with a recorded asbestos history, 72 had definite and 35 probable exposure; 19 recalled none. Excluding three patients diagnosed after death, median survival was 267 days (95% confidence interval 178 to 356), about 8.9 months. 110 of 146 presented with symptomatic fluid around the lung. Surgical pleurodesis (sealing the lung lining) was followed by fewer fluid recurrences than bedside pleurodesis (14% vs 47%), possibly reflecting patient selection, the authors said. Tumour growth along biopsy or drain tracts occurred in 1 of 49 patients without preventive radiotherapy and 6 of 73 with it, not a statistically significant difference. Only 26 of 146 entered chemotherapy trials. The authors concluded that survival was not improving and that preventive radiotherapy's timing and role need reappraisal.

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 audit of mesothelioma cases in a defined area, which the authors describe as capturing very nearly 100% of patients. Cases from 2002–2003 were analysed retrospectively and cases from 2004–2005 prospectively, using hospital records, the histology database and coroner's records.
• Who was studied: 146 confirmed cases of malignant mesothelioma diagnosed between 1 January 2002 and 31 December 2005 within the five Leeds primary care trusts (population 750 000), West Yorkshire, UK. Four further cases diagnosed only on clinical and CT evidence were excluded.
• Exposure: History of asbestos exposure recorded in case notes, classified as definite, probable (patients in high risk occupations who did not report definite exposure) or uncertain. No fiber types, products or doses were reported.
• Main results:
  • The calculated incidence was 4.9 per 100 000 population per year, with no obvious increase or decrease over the study period.
  • The median age at diagnosis was 74 years (range 36–93).
  • Asbestos histories were recorded for 126 of 146 patients. Among these 126, 72 (57%) reported definite exposure, 35 (28%) probable exposure, and 19 (15%) could not recall any exposure.
  • Median survival from diagnosis was 267 days (95% CI 178 to 356), about 8.9 months. The three patients diagnosed after death were excluded from this analysis.
  • Median survival by subtype: epithelioid 325 days (95% CI 240 to 410, n = 34); sarcomatoid 175 days (95% CI 0 to 445, n = 10); biphasic 161 days (95% CI 93 to 229, n = 9). Subtype was recorded in 36% of cases.
  • 110 of 146 patients (75%) had symptomatic pleural effusion at presentation.
  • Among patients whose pleural fluid was actively managed, recurrence was lower after surgical than after bedside pleurodesis (14% vs 47%; p = 0.02). Recurrence after bedside pleurodesis (8/17) versus chest drain only (9/26) was not statistically significant.
  • Of 122 patients who had thoracoscopic surgery, CT-guided cutting biopsy or chest drains, 73 (60%) received prophylactic radiotherapy. Tumour invasion of the tract occurred in 1 of 49 (2%) untreated patients and 6 of 73 (8%) treated patients (p = 0.243). The median time to tract metastasis was 174 days (range 76–360).
  • 54 of 146 patients (37%) were suitable for and offered chemotherapy. Of these, 28 of 54 (52%) declined, so 26 of 146 (18%) were randomised into chemotherapy trials.
  • Among patients fit enough to receive chemotherapy, median survival was 479 days (95% CI 421 to 537 days).
• The authors' conclusion: The authors concluded that median age at presentation is, as expected, increasing. They wrote that median survival is not improving and may be worsening, and that many patients have poor performance status and comorbidities that preclude palliative chemotherapy. They added that surgical pleurodesis appeared to be associated with fewer recurrences, possibly reflecting patient selection, and that the timing and role of prophylactic radiotherapy to biopsy sites needs reappraisal.
• Limitations the authors state:
  • A few patients with a Leeds postcode may have been referred to hospitals outside Leeds and missed.
  • Asbestos exposure histories initially recorded in medical notes may often be inaccurate.
  • The lower recurrence after surgical pleurodesis may reflect patient selection.
  • Complete data on the reasons for delays to prophylactic radiotherapy were not available.
  • Short survival may partly explain the low incidence of tract invasion.

Topics

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

Medical terms in this study, explained in our Lexicon: Epidemiology, Prognosis, Mesothelioma, Malignant Mesothelioma, Neoplasm, Histology, Median Survival, Pleural Effusion.

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