Clinical study of asbestos-related lung cancer

Our plain-English summary of Clinical study of asbestos-related lung cancer, by T. Kishimoto, K. Ohnishi, Y. Saito (Industrial Health, 2003).

The study

• Authors: T. Kishimoto, K. Ohnishi, Y. Saito
• Journal: Industrial Health
• Published: 2003;41(2):94-100
• Cited by: 13 articles, as counted by NIH iCite
• Read it: PubMed · Publisher

Abstract

We analyzed the characteristics of 120 patients of primary lung cancer supposed to be induced by exposure to asbestos. Most of 120 patients were male and the age ranged from 47 to 87 years with a median of 70 years. No particular tendency was observed in the histological types of the lung cancer in 120 patients. Forty of the 120 patients were heavy smokers. When the occupational history was analyzed, most of the patients had been exposed to asbestos in former Japanese naval shipyard, commercial shipyards, construction industry and ironworks. The term of asbestos exposure was 2 to 60 years with a median 27 years. Lung cancers appeared after 15 to 69 years with a median 43 years from the initial exposure to asbestos. Lung cancer was accompanied by asbestosis in 35 patients and by pleural plaques in 77. Twenty-two patients had both asbestosis and pleural plaques. The number of asbestos bodies per 5 g wet lung tissue for 72 patients whose lung tissues obtained from autopsy or surgery was more than 150 bodies which meant the number of occupational asbestos exposure. As for the kinds of asbestos fibers of 32 patients, 14 patients exposed to crocidolite, 10 patients to amosite and 8 patients to chrysotile.

In plain English

This study described 120 patients in Japan with primary lung cancer that the authors considered asbestos-related. They were diagnosed from 1995 to 2000 at Industrial Injury Hospitals and other public hospitals, and there was no comparison group. Inclusion required work exposure to asbestos plus asbestosis or pleural plaques, or, without these, at least 150 asbestos bodies per 5 g of wet lung tissue. Of the 120, 116 were men, and the median age at onset was 70. The most common job was shipbuilding (51 patients), followed by construction (18) and ironworks (15). Among 70 patients with known exposure duration, median exposure was 27 years and the median time from first exposure to lung cancer was 43 years. Asbestosis was found in 35 patients and pleural plaques in 77. In 72 patients whose lung tissue was examined, asbestos body counts ranged from 160 to 244,500 per 5 g. Counts were significantly higher in patients with asbestosis than in those with plaques only or neither. In 32 patients whose fibers were typed, the most frequent fiber was crocidolite in 14, amosite in 10 and chrysotile in 8. Only 10 patients had applied for workers' compensation. The authors concluded that physicians need education about asbestosis.

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: Descriptive clinical case series of patients with lung cancer judged asbestos-related (no comparison group)
• Who was studied: 120 patients (116 men, 4 women) with primary lung cancer considered asbestos-induced, diagnosed 1995 to 2000 at Industrial Injury Hospitals of the Labor Welfare Corporation, National Kure Hospital and Kure Kyosai Hospital in Japan. Inclusion required occupational asbestos exposure plus asbestosis or pleural plaques, or 150 or more asbestos bodies per 5 g wet lung tissue in patients without them.
• Exposure: Occupational asbestos exposure, most often in shipbuilding (51 patients, including former naval arsenal workers in rigging, plumbing and electric work). Others worked in construction (18), ironworks (15), slate manufacturing (7), plumbing (6), the automobile industry (4) and other jobs.
• Main results:
  • Age at onset ranged from 47 to 87 years, with a median of 70 years (all 120 patients).
  • Duration of asbestos exposure, for the 70 patients in whom it was known, ranged from 2 to 60 years, with a median of 27 years.
  • Time from first exposure to onset of lung cancer, for 70 patients, ranged from 15 to 69 years, with a median of 43 years.
  • Of the 120 cancers, 54 were squamous cell carcinomas, 51 adenocarcinomas, 11 small cell carcinomas and 4 large cell carcinomas.
  • Asbestosis was found in 35 of the 120 patients (25 with profusion rate 1, 7 with rate 2, 3 with rate 3).
  • Pleural plaques were found in 77 of the 120 patients. In 13 of these, the plaques were seen only at autopsy or surgery.
  • 22 patients had both asbestosis and pleural plaques. 30 had neither, but had more than 150 asbestos bodies per 5 g wet lung tissue.
  • In all 72 patients whose lung tissue was examined (from surgery or autopsy), asbestos bodies exceeded 150 per 5 g wet lung tissue. Counts ranged from 160 to 244,500, with a median of 12,680.
  • Mean asbestos bodies per 5 g wet lung tissue were: 16,712 plus or minus 13,564 with asbestosis and plaques; 22,529 plus or minus 20,238 with asbestosis without plaques; 4,651 plus or minus 6,904 with plaques only; 2,325 plus or minus 5,178 with neither.
  • Patients with asbestosis (with or without plaques) had significantly more asbestos bodies (p less than 0.0001) than patients with plaques only or with neither.
  • There was no significant difference in asbestos body counts between patients with plaques only and patients with neither asbestosis nor plaques.
  • Of 32 patients whose fibers were typed by electron microscopy, crocidolite alone was found in 14, amosite alone in 10 and chrysotile alone in 4.
  • In the remaining 4 patients, chrysotile was the most frequent fiber, with crocidolite also found in 3 and amosite in 1.
  • Only 4 patients were non-smokers, including 2 women.
  • Among 54 smokers, the Brinkman index ranged from 450 to 2,400 (median 900). 46 were heavy smokers.
  • All 120 patients met Japan's workers' compensation conditions, but only 10 had applied.
• The authors' conclusion: The authors concluded that physicians need education about asbestosis, so that they can diagnose it correctly in patients with findings such as pleural plaques.
• Limitations the authors state:
  • For 50 of the 120 patients, the duration of asbestos exposure was not confirmed, so duration and latency figures cover only 70 patients.
  • The authors noted that researchers do not fully agree on diagnostic criteria for asbestos-related lung cancer (the sentence in the text is missing a word).

Topics

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

Medical terms in this study, explained in our Lexicon: Lung Cancer, Occupational History, Asbestos Exposure, Pleural Plaques, Asbestos Bodies, Autopsy, Crocidolite, Amosite.

Related studies

• Asbestos-related occupational cancers compensated under the Industrial Accident Compensation Insurance in Korea — Y.S. Ahn, S.K. Kang (2009)
• Clinical study of asbestos-related lung cancer in Japan with special reference to occupational history — T. Kishimoto, K. Gemba, et al. (2010)
• Low-dose computed tomography (LDCT) in workers previously exposed to asbestos: detection of parenchymal lung disease — M.C. Carrillo, S. Alturkistany, et al. (2013)
• Effects of asbestos and smoking on gas diffusion in people exposed to crocidolite — H.S. Alfonso, L. Fritschi, et al. (2005)
• Mesothelioma risk and environmental exposure to asbestos: past and future trends in Japan — K. Azuma, I. Uchiyama, et al. (2009)
• Clinical study of asbestos-related lung cancer diagnosed by asbestos medical examination — T. Yotsumoto, A. Sano, et al. (2018)

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