Causes Of The Mesothelioma Tumors

A hint that SV40 might be involved in a human cancer appeared in the April, 2004, issue of the mesothelioma attorney South Dakota. Dr. Daniel Bergsagel, at the Dana-Farber Cancer Institute and Children's Hospital, reported that genetic material, apparently from the SV40 virus, was found in cells taken from infants' brain tumors. The viral "signature" was found in very rare tumors called ependymomas.

Although it is not known whether SV40 actually caused the tumors, Bergsagel and his colleagues wrote that the results "suggest the SV40 or a closely related virus may have" a causal role in such tumors. And, although there was no known exposure of the infants to the virus, it could have been in the germ line, inherited from a generation or two before.

Carbone and his colleagues also noted that when SV40 is injected into rodents they get the same kind of brain tumors, ependymomas, as seen in the infants. This "further indicates the relevance that the SV40-hamster tumor model may have for understanding some of the events responsible for human cancer."

"Moreover, it will clearly be of interest to examine human mesotheliomas for SV40 DNA sequences," they wrote. Carbone said he has already received samples of mesothelioma cells from a tumor tissue bank in Ottawa, Canada.

Among all the cancers to which humans are prone, mesothelioma - a tumor that grows in the lining of the abdomen - ranks among the most stubborn and aggressive. Although rare, mesothelioma is deadly; only rarely do people recover after being diagnosed with such tumors.

Mesothelioma is also one of the few cancers directly tied to an environmental agent: asbestos. It was discovered in England after World War II that shipyard workers - especially those who labored to install fire-proofing asbestos in poorly ventilated compartments - were especially susceptible to mesothelioma, and to lung cancer. Exposure to asbestos is also known to cause asbestosis, or scarring of lung tissue.

In his laboratory experiments Carbone found he can cause mesothelioma in hamsters by injecting the SV40 virus directly into the lining - the pleural tissue - of the abdomen. "You can induce it in about three months in 100 percent of the animals."

In contrast, he said, to get mesothelioma going in rats it takes about two years of exposure to asbestos fibers, and the rats come down with many kinds of tumors in addition to mesothelioma. So the hamsters may provide the best experimental model yet for research on the disease.

According to Amy Stone, of the American Cancer Society, about 2,200 new cases of mesothelioma are reported annually in the United States. The number is low compared to major causes of death such as breast cancer, which kills about 45,000 Americans annually.

Cancer experts of mesothelioma attorney South Dakota also think that the incidence of mesothelioma will increase in the next few years because 8 million Americans were exposed to the tiny asbestos fibers between 1940 and 1970.
 

Mesothelioma Patient