Mesothelioma Research

Asbestos-related diseases, including mesothelioma, have received increased recognition over the last few decades. Unfortunately, the amount of research into causes, treatments and incidences is less than many other diseases.

It is well-known today that asbestos is the primary cause of mesothelioma. However, decades ago, people were not aware of its harmful effects. In 1947, a case of pleural mesothelioma failed to acknowledge a link to asbestos, even though the patient was an asbestos worker who cut asbestos insulating board.

Finally, in 1960, asbestos was identified as a cause of mesothelioma in South Africa. Then, in 1992, researchers discovered that DNA can stick to asbestos fibers, transferring DNA from one cell to another. This can lead to mutations and cancers.

Many studies state that no form of asbestos is safe. In 1977, researchers discovered that tissues taken from mesothelioma patients contained a mixture of amphiboles and chrysotile. The study about DNA also showed that mesothelial cells are sensitive to all kinds of asbestos fibers.

In 1994, researchers observed the lung tissue of people with mesothelioma and uncovered that amosite asbestos was present in 81% of the samples. Actinolite, tremolite and anthophyllite were discovered in 55%, chrysotile in 21% and crocidolite in 16%. A study conducted in 1998 found that chrysotile asbestos is similar in potency of amphibole asbestos.

A 2002 study analyzed the type, number, and dimensions of asbestos fibers in both lung and mesothelial tissues in mesothelioma patients. Researchers discovered that asbestos fibers were present in nearly all of the lung and mesothelial tissues.

The study also found that the average number of asbestos fibers in both lung and mesothelial tissues was two orders of magnitude greater than the number found in the general population. Lung tissues of mesothelioma patients most often contained a combination of chrysotile with amphiboles, though some contained amphibole fibers alone and a smaller number contained chrysotile alone.

Chrysotile fibers were 30 times more likely than amphiboles to be found in mesothelial tissues. In certain patients, the only fibers found in the mesothelial or lung tissue were chrysotile fibers.

While crocidolite and amosite asbestos fibers have been most frequently associated with mesothelioma, chrysotile asbestos can also cause the disease. All types of asbestos are hazardous.

A study conducted in 1990 discovered that approximately 50% of mesothelioma patients by age 40 encountered asbestos in their childhood. These patients either lived close to asbestos plants or came in contact with fibers that were brought home on the skin, clothes or hair of a family member who worked with asbestos.

A 1994 study discovered that among male pleural mesothelioma patients, the attributable risk for exposure to asbestos was 88%. In male peritoneal cancer patients, it was 58%. For female mesothelioma patients, the attributable risk for exposure to asbestos was 23%. However, researchers wonder whether there was a greater misclassification among females because of the lack of understanding of non-occupational asbestos exposure.

A 1988 study compared asbestos fibers in mesothelioma patients and those in individuals who were not diagnosed with mesothelioma. The research found that patients with pleural mesothelioma had seven times as much asbestos in their tissues. Patients with peritoneal mesothelioma had 16 times as much.

In the late 1990s, a study investigated the history of cancer in first-degree relatives of mesothelioma patients. The research shows that those with a family history of cancer are more likely to develop mesothelioma, or may be more susceptible to asbestos exposure. This study may have indicated why people with only limited asbestos exposure have developed mesothelioma.

In 1997, studies showed that 80% of mesothelioma patients developed the disease in the pleura. Pleural mesothelioma rose by 300% in white males between 1973 and 1984. The median age for these patients was 60 years.