Malignant mesothelioma: clinical characteristics, asbestos mineralogy and chromosomal abnormalities of 41 patients

Our plain-English summary of Malignant mesothelioma: clinical characteristics, asbestos mineralogy and chromosomal abnormalities of 41 patients, by L. Tammilehto, T. Tuomi, M. Tiainen, et al (European Journal of Cancer, 1992).

The study

• Authors: L. Tammilehto, T. Tuomi, M. Tiainen, J. Rautonen, S. Knuutila, S. Pyrhönen, K. Mattson
• Journal: European Journal of Cancer
• Published: 1992;28A(8-9):1373-9
• Cited by: 20 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. 004889).

Abstract

The clinical characteristics and the results of mineral fibre and cytogenetic analyses were coordinated prospectively for 41 patients with confirmed malignant pleural mesothelioma. A correlation was found between high total fibre concentration, and partial or total loss of chromosomes 1, 4 and 9 and chromosomal rearrangements involving a breakpoint at 1p11-p22. There was also a correlation between crocidolite/amosite as the main fibre type and partial or total loss of chromosomes 1, 3 and 4 and chromosomal rearrangements involving del (3p). Positive prognostic factors were female gender, low total fibre concentration (less than 10(6) fibres per g dried lung tissue), anthophyllite as the main fibre type and normal chromosome 7. In addition, we found 4 patients with malignant mesothelioma who had been exposed mainly to anthophyllite fibres (total lung fibre concentrations of 1.2, 0.4, 0.2 and 0.1 x 10(6) fibres per g dried lung tissue). This would seem to indicate that there may be a carcinogenic role for anthophyllite.

In plain English

This Finnish study combined clinical, lung-fibre and tumour chromosome data on 41 patients with malignant mesothelioma (35 men, 6 women). The data were collected between 1982 and 1989 in the Helsinki University Central Hospital area. Lung fibre analysis was available for 27 patients and chromosome results for 36. Patients with higher total fibre counts more often had partial or total loss of chromosomes 1, 4 and 9. Patients whose main fibre type was crocidolite/amosite more often had loss of chromosomes 1, 3 and 4. Women lived longer than men (median 25 versus 8 months; P = 0.0019). Survival was better with fewer than 1 million fibres per gram of dried lung tissue (P = 0.031). It was best with anthophyllite as the main fibre type and worst with crocidolite/amosite (P = 0.021). Four patients had mainly anthophyllite in their lungs, which the authors wrote would seem to indicate a carcinogenic role for anthophyllite. The authors noted that they studied cells that were already malignant, and that fibre analysis was done for only 2 of the 6 women.

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: Prospectively collected clinical, mineralogical (lung fibre) and cytogenetic (chromosome) data on mesothelioma patients at one institution, analysed for correlations and survival
• Who was studied: 41 patients with mesothelioma (35 men, 6 women; median age 57, range 39 to 83), newly diagnosed 1982 to 1989 in the Helsinki University Central Hospital catchment area, Finland. Diagnoses were confirmed by Finnish and EORTC panels. 22 had both fibre and chromosome analyses, 14 chromosome analysis only, and 5 fibre analysis only.
• Exposure: Lung tissue fibre concentration and main fibre type, measured by scanning and transmission electron microscopy with X-ray microanalysis. Patients were grouped by main fibre type: group I, 50% or more crocidolite/amosite (15 patients); group II, 50% or more anthophyllite (4); group III, other fibre types (8); group IV, no fibre analysis (14).
• Main results:
  • Higher total fibre concentration correlated with partial or total loss of chromosome 1 (P = 0.0005, Table 4), chromosome 4 (P = 0.0069) and chromosome 9 (P = 0.0201).
  • Crocidolite/amosite as the main fibre type was accompanied by partial or total loss of chromosome 3 (P = 0.0322) and chromosome 4 (P = 0.0345), as well as chromosome 1 and del(3p) (P = 0.0207).
  • No chromosome change specific to mesothelioma was detected.
  • Median survival was 25 months for the 6 women and 8 months for the 35 men. Women lived longer than men (P = 0.0019).
  • Survival was better for patients with fewer than 1 million fibres per g dried lung tissue than for those with higher concentrations (P = 0.031).
  • Patients with crocidolite/amosite as the main fibre type had the worst prognosis and those with anthophyllite the best (P = 0.021).
  • Chromosome 7 abnormality was associated with poor prognosis (P = 0.038).
  • Four patients had been exposed mainly to anthophyllite. Their lung fibre concentrations were 1.2, 0.4, 0.2 and 0.1 million fibres per g dried lung tissue.
  • Using a criterion of more than 1 million fibres per g dried lung tissue, lung fibre counts indicated occupational exposure in 70% of the cases with fibre analysis.
  • Female gender correlated with very low fibre concentration (P = 0.022) and with anthophyllite as the main fibre type (P = 0.013).
• The authors' conclusion: The authors wrote that the 4 mainly anthophyllite-exposed cases would seem to indicate a carcinogenic role for anthophyllite. They also identified female gender, low total fibre concentration, anthophyllite as the main fibre type and normal chromosome 7 as positive prognostic factors.
• Limitations the authors state:
  • The chromosome findings came from cells that were already malignant, so they cannot show how asbestos started the cancer.
  • Fibre analysis was done for only 2 of the 6 women, and the 41 patients were selected.
  • Amosite and crocidolite could not easily be told apart by the analysis method.
  • The meaning of the link between breathlessness as the first symptom and low fibre counts was unclear.

Topics

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

Medical terms in this study, explained in our Lexicon: Malignant Mesothelioma, Mineralogy, Pleural Mesothelioma, Crocidolite, Amosite, Anthophyllite, Carcinogenic.

Related studies

• Abnormalities of chromosomes 7 and 22 in human malignant pleural mesothelioma: correlation between Southern blot and cytogenetic analyses — M. Tiainen, J. Kere, et al. (1992)
• Chromosomal abnormalities and their correlations with asbestos exposure and survival in patients with mesothelioma — M. Tiainen, L. Tammilehto, et al. (1989)
• Interphase cytogenetics on paraffin sections of malignant pleural mesothelioma. A comparison to conventional karyotyping and flow cytometric studies — M. Tiainen, A. Hopman, et al. (1992)
• Chromosomes and chromosomal evolution in human mesotheliomas as reflected in sequential analyses of two cases — G. Stenman, K. Olofsson, et al. (1986)
• Asbestos, chromosomal deletions, and tumor suppressor gene alterations in human malignant mesothelioma — S.S. Murthy, J.R. Testa (1999)
• Specificity of asbestos-induced chromosomal aberrations in short-term cultured human mesothelial cells — K. Olofsson, J. Mark (1989)

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