Diffuse malignant pleural mesothelioma in an urban hospital: clinical spectrum and trend in incidence over time

Our plain-English summary of Diffuse malignant pleural mesothelioma in an urban hospital: clinical spectrum and trend in incidence over time, by K.E. Shepherd, L.C. Oliver, H. Kazemi (American Journal of Industrial Medicine, 1989).

The study

• Authors: K.E. Shepherd, L.C. Oliver, H. Kazemi
• Journal: American Journal of Industrial Medicine
• Published: 1989;16(4):373-83
• Cited by: 16 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy (J-M no. 000156).

Abstract

This retrospective analysis reviews the clinical experience of a major urban referral hospital with diffuse malignant pleural mesothelioma during the 14-year period from 1973 through 1986. Seventy-five cases of definite or equivocal mesothelioma were identified. There were four cases of primary malignant peritoneal mesothelioma, seven cases of benign fibrous mesothelioma, and 64 cases of diffuse malignant pleural mesothelioma. In 43 cases (67%) of diffuse malignant pleural mesothelioma, there was historic evidence of asbestos exposure. In 21 cases (33%), there was no known history of asbestos exposure. An increase in annual incidence of diffuse malignant pleural mesothelioma was observed over the study period, from three cases in 1973 to ten cases in 1986. Despite greater awareness of this disease, the diagnosis remains a difficult one to establish given the nonspecific symptoms, signs and radiographic appearance, variable histologic appearance, and poor diagnostic sensitivity and specificity of thoracentesis and closed pleural biopsy. Thoracotomy, thoracoscopy, and CT-guided needle biopsies gave higher yields and are the diagnostic measures of choice when diffuse malignant pleural mesothelioma is suspected.

In plain English

This retrospective review covered coded mesothelioma patients at Massachusetts General Hospital from 1973 through 1986. Of 75 cases, 64 were diffuse malignant pleural mesothelioma; four peritoneal and seven benign fibrous cases were not analyzed. Of the 64, 46 (72%) had documented asbestos exposure. Three were identified only from lung tissue; 28 of 43 with exposure histories worked in shipyard trades. Annual cases rose from three (1973) to ten (1986). Male cases numbered 17 in 1973 to 1979 and 34 in 1980 to 1986. Women were 8 of 21 (38.1%) without an exposure history and 5 of 43 (11.6%) with one. The 18 non-asbestos-related patients averaged 56.9 years, versus 66.2 for the 46 asbestos-related. Pleural fluid cytology was clearly positive in four of 35 tested. Open pleural biopsy, CT-guided needle biopsy through the chest wall and thoracoscopy gave high yields; closed pleural biopsy often did not. The authors concluded that males with known exposure appeared to account for the rise. They judged their data insufficient to implicate hidden environmental exposure, except anecdotally. They named small numbers and the referral-hospital sample as weaknesses.

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 records (case series) at one hospital, a follow-up to an earlier report covering 1945 through 1972
• Who was studied: All patients with a coded histopathologic diagnosis of mesothelioma at Massachusetts General Hospital, Boston, 1973 through 1986. There were 75 cases: 64 diffuse malignant pleural mesothelioma (51 male, 13 female per Table I), 4 peritoneal mesothelioma and 7 benign fibrous mesothelioma. Only the pleural cases were analyzed.
• Exposure: Asbestos exposure was judged from medical records: reported use of asbestos at work, work at a naval shipyard, other nontrivial occupational or personal exposure, or interstitial fibrosis and/or asbestos bodies on pathology specimens. Most exposed patients worked in shipyard trades. Other sources were textile mill work, machinist and welder jobs, and one housewife exposed through a spouse's contaminated clothing. Fiber types were not specified.
• Main results:
  • Of the 64 diffuse malignant pleural mesothelioma cases, 46 (72%) had documented asbestos exposure.
  • 21 of the 64 cases (33%) had no history or clinical evidence of asbestos exposure. Three (14%) of these 21 had pathologic evidence of exposure and were counted as asbestos-related.
  • The annual number of diffuse malignant pleural mesothelioma diagnoses rose from three in 1973 to ten in 1986.
  • The increase was mainly among males: 17 cases (33.3%) in 1973 to 1979 and 34 cases (66.7%) in 1980 to 1986. Among females there were six cases in the earlier period and seven in the later period.
  • This comparison is based on exposure history alone. Females made up 38.1% (n = 8) of the 21 patients with no exposure history, compared with 11.6% (n = 5) of the 43 patients with an exposure history.
  • Table IV compares the 46 patients classed as asbestos-related (mean age 66.2 years) with the 18 classed as non-asbestos-related (mean age 56.9 years), p = .011. The text describes those with a history of exposure as significantly older.
  • Among those with known exposure, the latent period from first exposure to diagnosis ranged from 15 years upward, with the majority after 30 years.
  • A pleural effusion was the most common chest X-ray finding, present in 80% of patients.
  • Pleural fluid cytology was unequivocally positive in only four of 35 patients examined. Thoracentesis and closed pleural biopsy were often nondiagnostic. Open pleural biopsy (with or without lung biopsy), CT-guided transthoracic percutaneous needle biopsy and thoracoscopy gave high diagnostic yields.
  • Open pleural biopsy with or without lung biopsy, CT-guided transthoracic percutaneous needle biopsy and thoracoscopy gave high diagnostic yields. Thoracentesis and closed pleural biopsy often were nondiagnostic.
• The authors' conclusion: The authors concluded that males with known asbestos exposure appeared to account for the increasing trend. They suggested that people with nontrivial occupational exposure were surviving asbestosis and lung cancer and living out the longer latency of mesothelioma. They also said their data provided insufficient evidence to implicate occult environmental exposure as a cause other than on an anecdotal basis.
• Limitations the authors state:
  • Small numbers, and a sample limited to patients diagnosed at an urban referral hospital.
  • Larger numbers might have shifted the proportions of exposed and unexposed males and females.
  • Increasing physician awareness and referral could account for the apparent rise in incidence, and the authors could not rule this out.

Topics

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

Medical terms in this study, explained in our Lexicon: Pleural Mesothelioma, Mesothelioma, Peritoneal Mesothelioma, Asbestos Exposure, Thoracentesis, Pleural Biopsy, Thoracotomy, Thoracoscopy.

Related studies

• The significance of asbestos exposure in the diagnosis of mesothelioma: a 28-year experience from a major urban hospital — F.M. Hasan, G. Nash, et al. (1977)
• Asbestos bodies in bronchoalveolar lavage in the 21st century: a time-trend analysis in a clinical population — V. Nuyts, H. Vanhooren, et al. (2017)
• Time trends and spatial patterns in the mesothelioma incidence in Slovenia, 1961-2014 — V. Zadnik, M. Primic Zakelj, et al. (2017)
• Response to Letter to the Editor Regarding "Ambient Asbestos Fiber Concentrations and Long-Term Trends in Pleural Mesothelioma Incidence Between Urban and Rural Areas in the United States (1973-2012)" by Finkelstein — K.A. Keeton, M.E. Glynn, et al. (2018)
• Letter Concerning: Glynn ME, Keeton KA, Gaffney SH, Sahmel J. Ambient Asbestos Fiber Concentrations and Long-Term Trends in Pleural Mesothelioma Incidence Between Urban and Rural Areas in the United States (1973-2012). Risk Analysis 2018;38(3):454-471 — M.M. Finkelstein (2018)
• Time trend of mesothelioma incidence in the United States and projection of future cases: an update based on SEER data for 1973 through 2005 — B. Price, A. Ware (2009)

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