Asbestos-related diseases are complex and can be deadly. Understanding what causes these types of diseases and how they progress is important for detection and medical treatment purposes. Since 1972, the Surveillance, Epidemiology, and End Results (SEER) program of the National Cancer Institute has analyzed mesothelioma data, tracking incidence, mortality, and survival rates. This invaluable information serves members of the medical researching community as well as policymakers in their efforts to educate, protect and treat the public.
Asbestos usage in the United States peaked in the early 1970s, being widely used in construction, automotive and shipyard industries. Of the illnesses attributable to asbestos exposure, mesothelioma results from lesser levels and duration of exposure. Mesothelioma is also likely to be the outcome of asbestos exposure in a high percentage of cases, compared to lung cancer, which is often caused by smoking cigarettes. Those exposed to asbestos and subsequently developed mesothelioma are urged to call an asbestos attorney immediately to discuss a possible claim.
SEER currently reports cancer cases and data from 14 cancer registries, and their long-term case data are from five states: Hawaii, New Mexico, Iowa, Utah, and Connecticut. Trends are often fit to the male, age-adjusted rate because asbestos usage in the United States follows a distinct and clear pattern for this demographic. The rates most recently available are for the years between 1990 and 2005.
As previously noted, mesothelioma incidence is probably the best indicator of asbestos disease burden in the population and considerable effort has been devoted to examining trends in mesothelioma incidence in different countries. A report of observed rates through 1992, using the age-birth cohort model to project cases, estimated that the number of cases in the USA would peak in 1997 and subsequently decline. The updated rates reported here (through 2000) are reasonably consistent with these projections.
The vast majority of mesotheliomas in men in the USA (approximately 90%) are of pleural origin, and 90% or more of these tumors are caused by asbestos. Increasing male mesothelioma incidence for many years was undoubtedly the result of exposure to asbestos. The high mesothelioma risk was prominently influenced by exposure to amphibole asbestos (crocidolite and amosite), which reached its peak usage in the 1960-70s and thereafter declined. A differing pattern in some other countries (continuing rise in incidence) may be related to their greater and later amphibole use, particularly crocidolite. The known latency period for the development of this tumor provides biological plausibility for the recent decline in mesothelioma incidence in the United States. This favorable finding is contrary to a widespread fear that asbestos related health effects will show an inevitable increase in coming years, or even decades.
For males, the age-adjusted mesothelioma rate is increasing solely due to the age group 75 years and over, albeit at a declining growth rate. In addition to asbestos, other mineralogical, environmental, genetic, and possible viral factors might contribute to malignant mesothelioma susceptibility. Given these complexities, understanding susceptibility needs to be a priority for investigators in order to reduce exposure of those most at risk to known environmental carcinogens.
Malignant mesothelioma is ranked fourth in the list of 10 cancers with
the largest male-to-female incidence rate ratios. Occupational exposure
to asbestos in male-dominated professions is strongly associated with
risk. Thus, the observed gender-related differences in malignant mesothelioma
incidence may well by claimed to be largely due to occupational reasons.
Males have also been associated with predicting poor outcomes at diagnosis.
The time trend of mesothelioma incidence and projections of future cases provide useful information for analyzing proposed public health interventions where asbestos exposure may be an issue, evaluating regulatory proposals, and estimating the remaining potential costs of programs to compensate individuals with asbestos-related diseases.
The SEER data provide further evidence of a strong linkage between mesothelioma risk and exposure to amphibole asbestos and should lead to the avoidance of amphibole use in developing countries that may still be using this type of asbestos. If you or a loved one is suffering from an asbestos- related illness, contact a mesothelioma attorney today for a free legal consultation.