HOUSTON (March 9, 2002) -- Evidence of simian virus 40 (SV40) infection found in 42 percent of non-Hodgkin lymphoma samples could shed new light on the genesis of these blood cancers that have become more common over the past 30 years, said Baylor College of Medicine scientists in a report in the March 9 issue of The Lancet, a British scientific journal. About 55,000 new cases of the disease are diagnosed annually.
"This is an important finding because cancers with a viral cause offer the possibility of developing new and better ways of treating and diagnosing and ultimately preventing the tumor," said Dr. Janet Butel, chairman of the department of molecular virology and microbiology at Baylor and senior author of the report.
"This study further demonstrates that humans can be infected by SV40, an infection that was not suspected in the past," she said. SV40 usually infects rhesus monkeys. However, in the 1950s and early 1960s, some batches of polio vaccine became accidentally infected with the virus. The vaccine was then given to millions of people worldwide. Because some patients with SV40-positive tumors were born after 1963 and would not have been exposed to the contaminated vaccine, it appears that SV40 continues to spread among humans in ways that are not yet clear. Recently, evidence of SV40 infection has also been found in human brain tumors, tumors of the lining of the chest and abdomen (mesothelioma), and osteosarcomas.
In their study, Butel and Dr. Regis Vilchez, an assistant professor of medicine and first author on the report in The Lancet, analyzed samples from 154 patients who had lymphomas and found 42 percent positive for SV40 DNA, whereas many control samples were negative.
Dr. Adi Gazdar, a colleague at the University of Texas Southwestern Medical School in Dallas, performed a similar study that confirmed the presence of SV40 in samples of non-Hodgkin lymphomas. His study also appears in the March 9 issue of The Lancet.
Materials provided by Baylor College Of Medicine. Note: Content may be edited for style and length.
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