Survival of asbestos insulation workers with mesothelioma

Our plain-English summary of Survival of asbestos insulation workers with mesothelioma, by J. Ribak, I.J. Selikoff (British Journal of Industrial Medicine, 1992).

The study

• Authors: J. Ribak, I.J. Selikoff
• Journal: British Journal of Industrial Medicine
• Published: 1992;49(10):732-5
• Cited by: 18 articles, as counted by NIH iCite
• Read it: PubMed · Publisher · Free full text

Abstract

Malignant mesothelioma is a lethal disease. It is rare in the general population; however, workers exposed to asbestos suffer significant burdens of the neoplasm. The survival time of 457 consecutive fatal cases of pleural and peritoneal mesothelioma that occurred among 17,800 asbestos insulation workers observed prospectively from 1 January 1967 to 1 January 1987 was studied. Mean survival time from initial presentation of the disease to death was 11.4 months for the pleural mesothelioma patients compared with 7.4 months for the peritoneal group. This difference was statistically significant. Mean survival time from diagnosis to death was shorter for both groups of patients: 8.4 months for pleural mesothelioma v 5.8 months for the peritoneal cases. In conclusion, survival time in mesothelioma patients is short; most die within a year from the onset of the initial symptoms. No effective therapy is yet available.

In plain English

This study followed 17,800 asbestos insulation union members in the United States and Canada from 1967 to 1987. Among 5026 deaths, 457 were from malignant mesothelioma (186 pleural, 271 peritoneal). Only cases whose tissue slides the authors' pathologists reviewed were counted. The workers were described as exposed to chrysotile or chrysotile and amosite. About two thirds of the mesothelioma patients died before age 65. Among 385 cases with adequate data (141 pleural, 244 peritoneal), mean survival from first symptom to death was 11.4 months for pleural (median 10) and 7.4 months for peritoneal cases (median four), a statistically significant difference. Among 398 cases with adequate data, mean survival from diagnosis to death was 8.4 months for pleural and 5.8 months for peritoneal cases (medians five and two months). They found no survival differences between treatment types, or between treated and untreated patients. They noted that lead time bias from earlier pleural diagnosis must be considered. The authors concluded that survival is short, most patients die within a year of first symptoms, and no effective therapy is yet available.

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: Prospective cohort study; analysis of survival time in consecutive fatal mesothelioma cases within the cohort
• Who was studied: 17,800 members of the International Association of Heat and Frost Insulators and Asbestos Workers in the United States and Canada, observed from 1 January 1967 to 1 January 1987. There were 5026 deaths, of which 457 were mesothelioma (186 pleural, 271 peritoneal), accounting for 9.1% of deaths.
• Exposure: Asbestos insulation work. The authors describe this cohort as exposed to chrysotile or chrysotile and amosite.
• Main results:
  • The analysis of survival from first symptom to death covered 385 cases with adequate information: 141 pleural and 244 peritoneal. Information was not available for 45 pleural and 27 peritoneal cases.
  • From first symptom to death, pleural mesothelioma patients (141 with adequate data) had a mean survival of 11.4 months (SD 7.8) and a median of 10 months.
  • From first symptom to death, peritoneal mesothelioma patients (244 with adequate data) had a mean survival of 7.4 months (SD 5.8) and a median of four months.
  • The difference in survival from first symptom between the pleural and peritoneal groups was statistically significant (generalised Wilcoxon test).
  • The text states that within a year of first symptom, 63.4% of pleural patients and 86.3% of peritoneal patients had died.
  • Ten pleural and six peritoneal patients survived more than two years.
  • The analysis of survival from diagnosis to death covered 398 cases, according to the Table 2 title. Information was not available for 46 pleural and 13 peritoneal cases.
  • From diagnosis to death, pleural patients (140 with adequate data) had a mean survival of 8.4 months (SD 5.3) and a median of five months. Peritoneal patients had a mean of 5.8 months (SD 2.6) and a median of two months. The difference was statistically highly significant.
  • Approximately two thirds of the mesothelioma patients died before age 65.
  • Chemotherapy was the most frequent treatment. No therapy was recorded for 44 of 137 pleural patients (32.1%) and 82 of 219 peritoneal patients (37.3%) with treatment information.
  • No differences in survival time, either from diagnosis or from first symptom, were found between treatment modalities or between treated and untreated patients.
• The authors' conclusion: The authors concluded that survival time is short, that most patients die within a year of initial symptoms, and that no effective therapy is yet available.
• Limitations the authors state:
  • The longer survival of pleural patients may partly reflect lead time bias, because pleural mesothelioma tends to be diagnosed earlier.
  • The case definition was restrictive. Deaths diagnosed as mesothelioma were excluded if slides were not available for the authors' pathologists to review.
  • Adequate survival information was missing for some cases. For survival from first symptom, data were missing for 45 pleural and 27 peritoneal cases. For survival from diagnosis, data were missing for 46 pleural and 13 peritoneal cases.

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: Insulator, Mesothelioma, Malignant Mesothelioma, Neoplasm, Peritoneal Mesothelioma, Pleural Mesothelioma.

Related studies

• Influence of age at death on accuracy of death certificate disease diagnosis: findings in 475 consecutive deaths of mesothelioma among asbestos insulation workers and asbestos factory workers — I.J. Selikoff (1992)
• Lung cancer and mesothelioma during prospective surveillance of 1249 asbestos insulation workers, 1963-1974 — I.J. Selikoff (1976)
• Lung cancer and mesothelioma in the pleura and peritoneum among Swedish insulation workers — B. Järvholm, A. Sandén (1998)
• Asbestosis: interstitial pulmonary fibrosis and pleural fibrosis in a cohort of asbestos insulation workers: influence of cigarette smoking — R. Lilis, I.J. Selikoff, et al. (1986)
• Decline in death rates among asbestos insulation workers 1967-1986 associated with diminution of work exposure to asbestos — H. Seidman, I.J. Selikoff (1990)
• Asbestosis, laryngeal carcinoma, and malignant peritoneal mesothelioma in an insulation worker — A. Fischbein, J.C. Luo, et al. (1991)

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