Malignant mesotheliomas in Kure City, Japan: the relationship of asbestos exposure

Our plain-English summary of Malignant mesotheliomas in Kure City, Japan: the relationship of asbestos exposure, by T. Kishimoto, T. Sato, T. Ono, et al (Cancer Investigation, 1989).

The study

• Authors: T. Kishimoto, T. Sato, T. Ono, K. Okada, Y. Masuda, H. Ito
• Journal: Cancer Investigation
• Published: 1989;7(5):407-10
• Cited by: 7 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. 004759).

Abstract

Eighteen patients with malignant mesothelioma were seen at Kure Mutual Aid Hospital over a 10-year period. According to occupational history, chest x-ray manifestations, and evidence of asbestos bodies in the tissue, 13 of these cases were definitely thought to be due to exposure to asbestos as a result of two or three of these items testing positive. Kure City is one of the major ship-building cities in Japan since the 1920s. Most of the 18 patients worked in ship building before and during World War II. Malignant mesothelioma appeared about 40 years after their first exposure to asbestos. In western countries, most malignant mesotheliomas are thought to be induced by exposure to asbestos fibers (1,2). Consequently, there has been a serious effort to deal with this problem recently, including lowering rate of exposure. In Japan, however, there have been few reports that asbestos fibers caused malignant mesothelioma (3). This report suggests that an increased incidence of malignant mesotheliomas in a specific area of Japan may also be due to exposure to asbestos fibers.

In plain English

This report described 18 patients with malignant mesothelioma, diagnosed by pleural biopsy or autopsy, seen over 10 years at Kure Mutual Aid Hospital in Kure City, Japan. Sixteen were men and two were women, and the median age was 68. Fourteen tumors began in the pleura, three in the peritoneum and one in the pericardium. By occupational history, 15 of the 18 had worked around asbestos fibers, and 12 had worked for the Kure Ship Building Company or the Japanese Naval Dockyard before and during World War II. Chest x-rays showed pleural plaques (type IV in 6 patients, type V in 6) and asbestos-related lung fibrosis in 2. The text gave exposure as lasting 3 to 34 years (median 12), though the patient table lists one case at 35. Diagnosis came 20 to 49 years (median 43) after first exposure. Autopsied lungs showed numerous asbestos fibers in 6 of 13 patients and a considerably increased number in 6 others. Using occupational history, chest x-rays and lung findings, the authors considered 13 cases definitely due to asbestos. They concluded that the increase in mesothelioma in this area of Japan may be due to asbestos exposure.

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: case series (hospital-based review of 18 patients)
• Who was studied: 18 patients with malignant mesothelioma (16 male, 2 female; median age 68) diagnosed by pleural biopsy or autopsy at Kure Mutual Aid Hospital, Kure City, Japan, over a 10-year period. Autopsies were performed on 14.
• Exposure: Occupational asbestos exposure, mainly in shipbuilding: work for the Kure Ship Building Company or Japanese Naval Dockyard before and during World War II (jobs listed include shipfitter, welder, laborer, carpenter, watchman). Others worked at a steel company. Fiber types were not specified.
• Main results:
  • Site of origin: 6 right pleura, 8 left pleura, 3 peritoneum, 1 pericardium.
  • Median survival after admission to hospital was 6 months (range 1 to 26 months).
  • Histology: 4 epithelioid, 4 sarcomatous and 10 biphasic tumors.
  • By occupational history, 15 of the 18 patients had worked in an atmosphere of asbestos fibers.
  • On chest x-ray, 6 patients had pleural plaques of type IV and 6 had type V by the international classification. Another 2 had lung fibrosis attributed to asbestos fibers.
  • The Results text gives duration of asbestos exposure as 3 to 34 years (median 12 years). The duration column of Table 1 includes a value of 35 years, so the article is internally inconsistent on the maximum.
  • Time from first asbestos exposure to diagnosis of mesothelioma ranged from 20 to 49 years (median 43 years).
  • In autopsied lungs, numerous asbestos fibers were found in 6 of 13 patients and a considerably increased number in 6 others. The counting method actually counted asbestos bodies by light microscopy in 5 g of lung tissue.
  • 13 of the 18 cases were judged definitely due to asbestos exposure, because two or three of the three criteria (occupational history, chest x-ray findings, asbestos bodies in tissue) were positive.
  • The hospital saw only 2 mesothelioma patients before 1980, and 16 more in the past 5 years.
• The authors' conclusion: The authors concluded that an increased incidence of malignant mesothelioma in this specific area of Japan may also be due to exposure to asbestos fibers.

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, Asbestos Exposure, Occupational History, Chest X-Ray, Asbestos Bodies.

Related studies

• Malignant pleural mesothelioma in parts of Japan in relationship to asbestos exposure — T. Kishimoto, S. Ozaki, et al. (2004)
• A case-control study on occupational lung cancer risks in an industrialized city of Japan — N. Yamaguchi, M. Kido, et al. (1992)
• The relationship between malignant mesothelioma and an asbestos cement plant environmental risk: a spatial case-control study in the city of Bari (Italy) — M. Musti, A. Pollice, et al. (2009)
• 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)
• Incidence of interstitial lung disease in patients with mesothelioma in the west part of Japan — S. Nojiri, K. Gemba, et al. (2011)
• Physician requests by patients with malignant pleural mesothelioma in Japan — Y. Nagamatsu, I. Oze, et al. (2019)

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