Prognostic factors for malignant mesothelioma in 142 patients: validation of CALGB and EORTC prognostic scoring systems

Our plain-English summary of Prognostic factors for malignant mesothelioma in 142 patients: validation of CALGB and EORTC prognostic scoring systems, by J.G. Edwards, K.R. Abrams, J.N. Leverment, et al (Thorax, 2000).

The study

• Authors: J.G. Edwards, K.R. Abrams, J.N. Leverment, T.J. Spyt, D.A. Waller, K.J. O'Byrne
• Journal: Thorax
• Published: 2000;55(9):731-5
• Cited by: 235 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Background: The incidence of malignant mesothelioma is increasing. There is the perception that survival is worse in the UK than in other countries. However, it is important to compare survival in different series based on accurate prognostic data. The European Organisation for Research and Treatment of Cancer (EORTC) and the Cancer and Leukaemia Group B (CALGB) have recently published prognostic scoring systems. We have assessed the prognostic variables, validated the EORTC and CALGB prognostic groups, and evaluated survival in a series of 142 patients.

Methods: Case notes of 142 consecutive patients presenting in Leicester since 1988 were reviewed. Univariate analysis of prognostic variables was performed using a Cox proportional hazards regression model. Statistically significant variables were analysed further in a forward, stepwise multivariate model. EORTC and CALGB prognostic groups were derived, Kaplan-Meier survival curves plotted, and survival rates were calculated from life tables.

Results: Significant poor prognostic factors in univariate analysis included male sex, older age, weight loss, chest pain, poor performance status, low haemoglobin, leukocytosis, thrombocytosis, and non-epithelial cell type (p<0.05). The prognostic significance of cell type, haemoglobin, white cell count, performance status, and sex were retained in the multivariate model. Overall median survival was 5.9 (range 0-34.3) months. One and two year survival rates were 21.3% (95% CI 13.9 to 28.7) and 3. 5% (0 to 8.5), respectively. Median, one, and two year survival data within prognostic groups in Leicester were equivalent to the EORTC and CALGB series. Survival curves were successfully stratified by the prognostic groups.

Conclusions: This study validates the EORTC and CALGB prognostic scoring systems which should be used both in the assessment of survival data of series in different countries and in the stratification of patients into randomised clinical studies.

In plain English

The authors reviewed case notes of 142 consecutive patients with malignant mesothelioma (13 women, 129 men) seen in Leicester, UK, since 1988. They examined survival factors and tested two published risk scoring systems (EORTC and CALGB). Overall median survival from diagnosis was 5.9 months. One-year survival was 21.3% (95% confidence interval 13.9 to 28.7) and two-year survival 3.5% (0 to 8.5). Analysed one at a time, male sex, older age, weight loss, chest pain, poorer performance status, abnormal blood counts and non-epithelial cell type were linked to shorter survival. A history of asbestos exposure (87 patients with such a history and 20 without, in the study's table) was not a statistically significant prognostic factor (p = 0.73). In a combined analysis of 101 patients with complete data, cell type, haemoglobin, white cell count, performance status and sex remained significant. Within risk groups, Leicester survival was generally comparable to the EORTC and CALGB series, though the EORTC high-risk median fell just outside the Leicester confidence interval and some CALGB groups had few patients. The authors concluded that, grouped by risk, their patients survived no worse than those series.

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 hospital case notes, with data collected prospectively from August 1998. It was a prognostic factor analysis using Cox regression and a test of two existing prognostic scoring systems (EORTC and CALGB).
• Who was studied: 142 consecutive patients with malignant mesothelioma (13 women, 129 men; median age 64, range 42 to 86) who presented to the Cardiothoracic Surgical Service in Leicester, UK, since 1988. Survival data were available for 138 patients, and complete data for 101.
• Exposure: This was not a study of asbestos exposure. A history of asbestos exposure was recorded as one of several possible prognostic factors. The article says 81% of patients gave such a history. Table 1 lists 87 patients with an exposure history and 20 without. No fiber types, products, jobs or doses were given.
• Main results:
  • All patients: median survival from histological diagnosis was 5.9 months (range 0 to 34.3). One-year survival was 21.3% (95% CI 13.9 to 28.7) and two-year survival was 3.5% (0 to 8.5).
  • In single-factor (univariate) analysis, these clinical factors were statistically significant poor prognostic factors: male sex (hazard ratio 2.24, 95% CI 1.10 to 4.52), older age, weight loss of more than 5%, pleuritic chest pain, and ECOG performance status above 0 (hazard ratio 3.33).
  • In univariate analysis, low haemoglobin, high white blood cell count and thrombocytosis (high platelet count) were also significantly associated with poor prognosis.
  • Epithelial cell type had a better prognosis than mixed and sarcomatoid types (univariate hazard ratio for mixed/sarcomatoid 2.71, 95% CI 1.80 to 4.08, p less than 0.0001).
  • A history of asbestos exposure (Table 1: 87 patients with such a history, 20 without) was not a statistically significant prognostic factor (hazard ratio 1.10, 95% CI 0.65 to 1.84, p = 0.73).
  • Patients who had surgical resection showed a trend towards longer survival, but it was not statistically significant (p = 0.09).
  • In the multivariate model (101 patients with complete data), five variables remained significant: cell type, haemoglobin, white blood cell count, performance status and sex (sex hazard ratio 3.13, 95% CI 1.33 to 7.14, per Table 2).
  • Multivariate model: non-epithelial cell type had a hazard ratio of 2.33 (95% CI 1.46 to 3.72).
  • Multivariate model: each 1 g/dl rise in haemoglobin went with a 21% fall in risk. Each rise of 1 x 10 to the 9th per litre in white blood cell count went with an 11% rise in risk.
  • Multivariate model: ECOG performance status of 1 or 2 had a hazard ratio of 2.01 (95% CI 1.24 to 3.28).
  • A significantly greater share of Leicester patients fell in the EORTC high risk group than in the original EORTC series (60% vs 42%, p = 0.002).
  • EORTC groups: median survival was 9.4 months in Leicester vs 10.8 in the EORTC series for the low risk group (49 Leicester patients), and 3.8 vs 5.5 months for the high risk group (75 Leicester patients). The EORTC figure fell within the Leicester 95% CI for the low risk group and just outside it for the high risk group. The authors reported one- and two-year survival as equivalent.
  • When grouped by CALGB criteria, median, one-year and two-year survival in Leicester were comparable to the published CALGB series. CALGB groups 2, 4 and 6 had only two, five and nine Leicester patients.
• The authors' conclusion: The authors concluded that the study validated the EORTC and CALGB prognostic scoring systems. They found survival in their series no worse than in the two chemotherapy-based series once patients were stratified into prognostic groups, and said these groups should be used in planning future clinical trials.
• Limitations the authors state:
  • Complete data were available for only 101 of 142 patients, because case notes were missing or destroyed or data were missing from them.
  • Diagnoses relied on the original pathology reports; tissue sections were not re-examined.
  • Retrospective TNM (IMIG) staging was judged not accurate enough, so survival by stage was not assessed.
  • Some CALGB groups had very few patients, so groups were combined for the survival plot.

Topics

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

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Performance Status, Median Survival.

Related studies

• 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)
• Malignant peritoneal mesothelioma: prognostic significance of clinical and pathologic parameters and validation of a nuclear-grading system in a multi-institutional series of 225 cases — D.B. Chapel, J.J. Schulte, et al. (2021)
• Health-related quality of life in patients with lung cancer: validation of the Mexican-Spanish version and association with prognosis of the EORTC QLQ-LC13 questionnaire — Ó. Arrieta, C. Núñez-Valencia, et al. (2012)
• Poor Prognostic Factors in Patients with Malignant Pleural Mesothelioma Classified as Pathological Stage IB According to the Eighth Edition TNM Classification — T. Takuwa, M. Hashimoto, et al. (2018)
• Survival and prognostic factors in malignant pleural mesothelioma: a retrospective study of 314 patients in the west part of Japan — S. Nojiri, K. Gemba, et al. (2011)
• Prognosis and prognostic factors of patients with mesothelioma: a population-based study — S. van der Bij, H. Koffijberg, et al. (2012)

Browse more research in Thorax, or return to medical research.