Report: Link Between Viruses and Cancer May be Overestimated
DNA viruses play no role in most major cancers, authors say (August 5)
The results of a large-scale analysis of the association between DNA viruses and human malignancies suggest that many of the most common cancers are not associated with DNA viruses. The new findings challenge earlier studies, which suggested that up to 40% of tumors may be caused by viruses.
The new report was published in the August 2013 issue of the Journal of Virology, a publication of the American Society for Microbiology (ASM).
For years, scientists believed viruses played a role in the development of 10% to 20% of cancers. In 2011, scientists at the Karolinska Institute in Sweden identified potential viral links to several cancers not previously associated with viruses, including brain tumors and prostate cancer, suggesting that the real number could be as high as 40%. Since then, researchers have been working to find more associations, partly because viruses could provide targets for vaccines to prevent or cure these cancers.
To better understand the role of DNA viruses in human cancers, researchers at the MD Anderson Cancer Center in Houston sequenced RNA from 3,775 malignant tumor samples and applied a bioinformatics algorithm to survey them for the presence of viral transcripts.
Cancers found not to be associated with DNA viruses included acute myeloid leukemia, cutaneous melanoma, low- and high-grade gliomas of the brain, and adenocarcinomas of the breast, colon and rectum, lung, prostate, ovaries, kidneys, and thyroid gland.
The findings, says study co-author Dr. Xiaoping Su, suggest that the estimate that 40% of tumors are virus-related “should be much lower.”
The new data also provide a framework for understanding how viruses integrate into cancer subtypes, such as hepatocellular cancer, Su says. That might make it possible to personalize treatments by targeting genes that are located within known integration sites and that might be drivers of cancer initiation and progression.
Source: ASM; August 5, 2013.