Malignant mesothelioma: a clinical study of 238 cases

Our plain-English summary of Malignant mesothelioma: a clinical study of 238 cases, by S.E. Haber, J.M. Haber (Industrial Health, 2011).

The study

• Authors: S.E. Haber, J.M. Haber
• Journal: Industrial Health
• Published: 2011;49(2):166-72
• Cited by: 31 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

Malignant mesothelioma is a diffuse tumor arising in the pleura, peritoneum, or other serosal surface and is closely associated with asbestos exposure. An estimated 2,500 to 3,000 cases are diagnosed each year in the United States. Although there are individual case reports and small series detailing the clinical aspects of mesothelioma, few studies examine a large series of patients with malignant mesothelioma from the clinical perspective. This study reports on the findings of 238 cases of malignant mesothelioma from a private consultative medical practice. Most cases had a history of occupational asbestos exposure. The mean latency was 48.5 yr, with women having a longer latency than men. The mean age at diagnosis was 70. Survival overall was poor (mean 8.8 months), but treatment was beneficial (mean 11.3 versus 6.4 months). Epithelioid histology conferred a survival advantage over sarcomatoid and responded better to treatment. Our data support an inverse relationship between asbestos dose and latency.

In plain English

This was a case series from the Texas Occupational Medicine Institute, a private practice in Houston. Of 286 people diagnosed with malignant mesothelioma between 1977 and 2009, 238 (217 men, 21 women) had enough information for analysis. Of the tumors with a recorded site, 221 were pleural and 13 peritoneal. Most patients (91%) had occupational asbestos exposure, and pipefitter/plumber was the most common occupation. The article did not report which asbestos fiber types its own patients were exposed to. A clinician rated exposure as heavy in 50%, moderate in 37.1% and light in 12.9%. Mean latency from first exposure to diagnosis was 48.5 years, and it was longer in women than in men (53.3 versus 47.9 years, p less than 0.05). Pleural plaques were found in 124 of 224 cases and asbestosis in 63 of 223. Trimmed mean survival was 8.8 months. Treated patients survived longer than untreated patients (11.3 versus 6.4 months), and epithelioid tumors had longer survival than sarcomatoid ones (12.2 versus 7.3 months). The authors concluded that women's longer latency supported the idea that heavier exposure shortens latency. They noted possible selection bias because most cases were medicolegal.

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: Clinical case series drawn from the medical and consultative files of a private pulmonary and occupational medicine practice
• Who was studied: 238 people with pathology-confirmed malignant mesothelioma (217 men, 21 women), out of 286 identified in the files of the Texas Occupational Medicine Institute, Houston, Texas, diagnosed between 1977 and 2009; mean age at diagnosis 70.3 years
• Exposure: Asbestos exposure, mostly occupational (91%); the article does not report which fiber types the patients were exposed to. A TOMI physician rated exposure from work histories as heavy (50%), moderate (37.1%) or light (12.9%). The most common occupation was pipefitter/plumber. The most common setting was petrochemical, followed by construction and shipyard.
• Main results:
  • Of cases with tumor location given, 221 were pleural (94.4%) and 13 peritoneal (5.6%)
  • Pipefitter/plumber was the most common occupation among the 202 cases with occupation data (37 cases, 18.3%)
  • Women were more likely than men to have only non-occupational exposure (76.2% of women)
  • Mean latency (first exposure to diagnosis), calculated in 191 cases, was 48.5 years, range 18 to 70
  • Women had a longer latency than men: 53.3 versus 47.9 years, p less than 0.05
  • Latency for insulators was not statistically different from that of other occupations
  • Pleural plaques were present in 124 of 224 cases (55.3%)
  • Asbestosis was present in 63 of 223 cases (28.3%), all in men
  • Overall trimmed mean survival was 8.8 months
  • Among the 219 cases with treatment information, survival was longer with treatment than without: trimmed mean 11.3 versus 6.4 months, p less than 0.001
  • Epithelioid tumors had longer survival than sarcomatoid tumors overall: mean 12.2 versus 7.3 months, p less than 0.05
  • Those diagnosed before age 60 survived longer than those 60 or older (13.7 versus 9.7 months), but the difference was not statistically significant
  • The authors could not identify any particular treatment type or combination as superior
• The authors' conclusion: The authors concluded that the longer latency they found in women, who likely had lesser exposures, supported the hypothesis that heavier asbestos exposure is linked to shorter latency. They also reported a small but statistically significant survival prolongation with treatment.
• Limitations the authors state:
  • Possible selection bias, because most cases were medicolegal
  • The light/moderate/heavy exposure classification was subjective
  • Too few women had plaques for statistical analysis
  • Breast shadows may have hidden non-calcified plaques in women

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: Malignant Mesothelioma, Pleura, Peritoneum, Serosal Surface, Asbestos Exposure, Mesothelioma, Latency, Epithelioid.

Related studies

• Type of asbestos and respiratory cancer in the asbestos industry — P.E. Enterline, V. Henderson (1973)
• Respiratory carcinogenesis: an epidemiologic appraisal — J.F. Fraumeni (1975)
• The epidemiology and treatment of mesothelioma in South East England 1985-2002 — V. Mak, E. Davies, et al. (2008)
• Cancer mortality in U.S. counties with shipyard industries during World War II — W.J. Blot, B.J. Stone, et al. (1979)
• Classics in Oncology: Asbestos exposure and neoplasia — I.J. Selikoff, J. Churg, et al. (1984)
• Man-made vitreous fibers and risk of respiratory system cancer: a review of the epidemiologic evidence — I.M. Lee, C.H. Hennekens, et al. (1995)

Browse more research in Industrial Health, or return to medical research.