Asbestos Toxicity
What Other Health Conditions Are Associated with Asbestos?
Course: WB 2344
CE Original Date: January 29, 2014
CE Renewal Date: January 29, 2016
CE Expiration Date: January 29, 2018
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Learning Objectives |
Upon completion of this section, you will be able to
- Identify non-respiratory conditions that might be associated with exposure to asbestos.
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Introduction |
Evidence indicates that exposure to asbestos leads to conditions outside the respiratory system, including
- Peritoneal mesothelioma,
- Other extra-thoracic cancers, and
- Cardiovascular conditions secondary to pulmonary fibrosis.
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Peritoneal Mesothelioma |
Peritoneal mesothelioma is similar to pleural mesothelioma except that it arises in peritoneal membranes. Like pleural mesothelioma, this tumor is rapidly locally invasive and often rapidly fatal after it is diagnosed.
Peritoneal mesothelioma is rare. In men, 90% of all mesotheliomas are pleural [Weill et al. 2004]. In addition, the sex difference in incidence is smaller with peritoneal mesothelioma than for pleural mesothelioma [Hillerdal 1999].
The table below shows male to female incidence ratios for the two different types of mesothelioma.
Table 9. Sex Ratios for Different Types of Mesothelioma
| Type of Mesothelioma |
Male:Female Incidence Ratio |
| Pleural |
5:1 |
| Peritoneal |
1.5:1 |
Source: Hillerdal 1999 |
Other Extra-thoracic Cancers |
Researchers and regulators have not been able to reach a consensus on the effects of asbestos on extra-thoracic cancers. Both the Institute of Medicine (IOM) and the International Agency for Research on Cancer (IARC) have reviewed the state of the evidence regarding the role of asbestos in causing selected extra-thoracic cancers. The recent IARC panel determinations are presented below.
Table 10. Other Extra-thoracic Cancers
| Type of Cancer |
Evidence for Causality by Asbestos |
| Laryngeal |
Sufficient evidence for increased risk in asbestos-exposed workers |
| Ovary |
Sufficient evidence for increased risk in asbestos-exposed women |
| Pharyngeal |
Evidence for associated risk from asbestos exposure is suggestive but not sufficient. More research is needed. |
| Stomach |
Evidence for associated risk from asbestos exposure is suggestive but not sufficient. More research is needed. |
| Colorectal |
Evidence for risk from asbestos exposure is suggestive but not sufficient. More research is needed. The IARC working group was evenly divided on whether the evidence was sufficient to designate causality. |
| Esophageal |
Inadequate evidence exists to determine the risk from asbestos exposure. |
Source: IARC 2012
Despite the lack of scientific consensus on the role of asbestos in gastrointestinal cancers, ATSDR and the National Toxicology Program (NTP) concur that it is prudent to consider increased risk of gastrointestinal cancer a possible effect of asbestos exposure [ATSDR 2001a; American Thoracic Society 2004; National Toxicology Program 2011]. Colon cancer screening starting at age 50 is recommended using accepted guidelines [Agency for Healthcare Research and Quality, 2008] but on the basis of current evidence, screening for other extrathoracic cancers in people exposed to asbestos is not currently recommended [American Thoracic Society 2004; Griffith and Maloney 2003]. |
Cardiovascular Conditions |
Cor pulmonale occurs in many forms of far advanced lung disease when fibrosis of the lungs leads to increased resistance to blood flow through the capillary bed. This condition is most commonly seen in patients with severe asbestosis, though it can also occur with less severe fibrotic disease, especially if chronic obstructive pulmonary disease is simultaneously present, as is often the case with asbestos workers who have been smokers.
Constrictive pericarditis rarely occurs secondary to severe asbestos-induced fibrosis or calcification of the pericardium. |
Key Points |
- Pleural and peritoneal mesothelioma is a rare, rapidly invasive tumor caused by asbestos exposure.
- Asbestos exposure is a known risk factor for laryngeal cancer and ovarian cancer.
- Asbestos exposure might be associated with some other extrathoracic cancers, especially colon cancer.
- Cor pulmonale can occur secondary to pulmonary fibrosis, mainly in patients with severe asbestosis.
- Rarely, constrictive pericarditis can occur secondary to asbestos-associated disease.
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Progress Check |
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