Simian Virus SV40

One new and highly contentious issue is the role of simian virus 40 (SV40) in the development of mesothelioma tumors. Animal experiments have established that SV40 is a potent tumor inducing virus, however, clinical studies still have not conclusively linked SV40 to human mesothelioma cases. Many studies and publications have demonstrated the presence of SV40 in human mesothelioma tissue samples.

There is some evidence, however, that the SV40 presence in the samples may be due to pervasive laboratory contamination. The source of this contamination was the original monkey cell cultures used as a medium in which to grow smallpox vaccines. The SV40 remnants were felt to be benign and were therefore ignored by laboratories. it was only later that the tentative connection to cancer was noted.

It is also interesting that the presence of SV40 in pathology samples is statistically indicative of a poor outcome, suggesting that asbestos and SV40 may interact in the spread and aggressiveness of mesothelioma tumors. More research is necessary before we can claim to have a causal link between SV40 and human malignant mesothelioma.