Sputum cytology of asbestosis patients

Our plain-English summary of Sputum cytology of asbestosis patients, by M.S. Huuskonen, E. Taskinen, V. Vaaranen (Scandinavian Journal of Work, Environment & Health, 1978).

The study

• Authors: M.S. Huuskonen, E. Taskinen, V. Vaaranen
• Journal: Scandinavian Journal of Work, Environment & Health
• Published: 1978;4(4):284-94
• Cited by: 4 articles, as counted by NIH iCite
• Read it: PubMed · Publisher
• In J-M's library: Johns-Manville's company medical library held a copy.

Abstract

One hundred and fourteen patients with asbestosis, 59% of whom were chronic cigarette smokers, were subjected to a cytological sputum examination which showed: 36 workers (31.6%) with squamous metaplasia, 20 (17.5%) with benigh columnar cell atypia, 5 (4.4%) with benign dysplasia, 2 with suspicious cells for carcinoma, and 1 with anaplastic (microcellular) carcinoma. Clinically and histologically five lung cancers were verified, two of which were cytologically false negatives. All asbestosis patients with lung cancer were chronic smokers. Of the 114 asbestosis patients, 49 (43.0%) had ferruginous bodies in their sputum. The workers from an asbestos quarry more frequently had ferruginous bodies in their specimens than the other patients. Radiographically moderate and severe asbestosis cases showed squamous metaplasia more frequently than those with radiographically slight asbestosis. Most of the detected cellular atypias represented reversible alterations of the respiratory epithelium. It is, however, important to screen the sputum of older (greater than 40 years of age) smoking asbestos workers with benign and suspicious cellular atypias regularly because these alterations may represent the first step int he pathway to bronchogenic cancer. The results of this study did not answer the question of whether bronchial cancer of patients with asbestosis is curable if detected early with cytological methods.

In plain English

This Finnish study examined sputum (coughed-up mucus) under the microscope in 114 patients with asbestosis diagnosed by the Institute of Occupational Health between 1964 and 1976. Of these patients, 59% were chronic cigarette smokers. They had worked as insulators or asbestos sprayers, in an asbestos cement product factory, in an asbestos quarry, or in other industries. Benign cell changes were found in 61 patients, most often squamous metaplasia (36, 31.6%). Two patients had cells suspicious for carcinoma, and one had cells of microcellular (small-cell) carcinoma. Five lung cancers were verified clinically or histologically. Sputum testing missed two of them, and all patients with lung cancer were chronic smokers. Ferruginous bodies appeared in the sputum of 49 patients (43.0%), more often among quarry workers. Squamous metaplasia was less common in radiographically slight asbestosis (11 of 52) than in moderate and severe cases (25 of 62). The authors concluded that most cell changes were reversible, but that sputum of smoking asbestos workers over 40 with benign or suspicious atypias should be screened regularly. They said the study did not answer whether early detection by sputum testing makes these cancers curable.

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: Cross-sectional cytological (sputum) examination of asbestosis patients, with comparison to earlier sputum examinations for a subgroup of 33
• Who was studied: 114 asbestosis patients (99 men, 15 women by Table 1) diagnosed by the Institute of Occupational Health, Helsinki, Finland, between 1964 and 1976; mean age 56.0; 59% chronic cigarette smokers
• Exposure: Occupational asbestos exposure as insulators, asbestos sprayers, asbestos cement product factory workers, asbestos quarry workers and others including shipbuilding. Sprayers were exposed to crocidolite and quarry workers to anthophyllite. Other occupations had mixed exposure, mainly chrysotile with smaller amounts of anthophyllite, crocidolite and amosite. Mean exposure length was 22.1 years (range 3 to 44).
• Main results:
  • Squamous metaplasia was found in 36 of the 114 asbestosis patients (31.6%), benign columnar cell atypia in 20 (17.5%), and benign dysplasia in 5 (4.4%)
  • 2 patients had cells suspicious for carcinoma and 1 had cells of anaplastic (microcellular) carcinoma; no false positive findings occurred
  • Five lung cancers were verified clinically or histologically among the 114 patients; two were cytologically false negatives
  • All asbestosis patients with lung cancer were chronic smokers
  • 49 of the 114 patients (43.0%) had ferruginous bodies in their sputum; asbestos quarry workers had them more often than the other groups (15 of 23, 65.2%; chi-square 9.31, p less than 0.01)
  • Squamous metaplasia was less common in radiographically slight asbestosis (11 of 52) than in radiographically moderate and severe asbestosis (25 of 62); chi-square 3.96, p less than 0.05
  • Smoking habits, length of exposure and occupation were not related to any form of benign atypia
  • 89 of the 114 patients (78.1%) had cell findings indicating inflammation; these were less frequent in radiographically slight asbestosis
  • 23 patients (20.2%) had eosinophils in sputum; asbestos quarry workers had them more often than other occupations (chi-square 10.40, p less than 0.01)
  • Of 33 workers whose sputum had first been examined seven years earlier, 3 showed clear progression from normal or metaplastic cells to dysplastic or malignant cells
  • The type of asbestos, according to occupation, had no significant effect on cellular atypias, inflammatory findings or ferruginous bodies
• The authors' conclusion: The authors concluded that most cellular atypias were reversible changes. They considered it important to screen the sputum of older (over 40) smoking asbestos workers with benign or suspicious cellular atypias regularly, because these changes may be a first step toward bronchogenic cancer. They also concluded that ferruginous bodies in sputum seem to indicate only exposure to asbestos dust. They said the study did not answer whether bronchial cancer in asbestosis patients is curable if detected early by cytology.
• Limitations the authors state:
  • The material was too small for definitive conclusions about whether adenocarcinoma was overrepresented
  • The lack of a smoking effect on benign atypia may reflect the small size of the material
  • The asbestos sprayers group was too small for a significant comparison of ferruginous bodies with other groups
  • The way sputum was collected (morning specimens rather than aerosol-induced) may have affected the number of insufficient specimens (10 patients, 8.8%)

Topics

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

Medical terms in this study, explained in our Lexicon: Sputum, Cytology, Columnar Cell, Carcinoma, Lung Cancer, Ferruginous body, Epithelium, Bronchogenic Carcinoma.

Related studies

• Asbestos bodies in the sputum of asbestos workers: correlation with occupational exposure — C. Paris, F. Galateau-Salle, et al. (2002)
• Assessment of hazardous dust exposure by BAL and induced sputum — E. Fireman, J. Greif, et al. (1999)
• Copy number gains on 5p15, 6p11-q11, 7p12, and 8q24 are rare in sputum cells of individuals at high risk of lung cancer — E. Kettunen, K. Salmenkivi, et al. (2006)
• Perls' Prussian Blue Stains of Lung Tissue, Bronchoalveolar Lavage, and Sputum — A.J. Ghio, V.L. Roggli (2021)
• A method for extracting ferruginous bodies from sputum and pulmonary tissue — M.J. Smith, B. Naylor (1972)
• A procedure for the isolation of amosite asbestos and ferruginous bodies from lung tissue and sputum — M.G. Williams, R.F. Dodson, et al. (1982)

Browse more research in Scandinavian Journal of Work, Environment & Health, or return to medical research.