Causality of mesothelioma: SV40 question.
The fragility of the evidence for SV40 association with human cancer is seen in studies of NHL. A publication in 1999 stated that SV40 is rarely present in NHL. In 2002, two laboratories reported SV40 sequences in 42% to 43% of cases of NHL . One of these laboratories also detected SV40 sequences in small proportions of pediatric tumors (e.g., Wilm's tumor, hepatoblastoma, rhabdomyosarcoma, medulloblastoma, osteosarcoma, and retinoblastoma) and adult carcinomas (e.g., lung, colon, breast, and prostate) These positive results were not confirmed in subsequent studies published in 2003. Capello et al and Mackenzie et al failed to detect SV40 sequences in NHL tissues. Sanjose et al examined sera from patients with NHL and from controls for antibodies reactive to SV40 VLPs, and they detected no significant differences between the two groups. The association of SV40 with NHL is in doubt. An etiologic link between a virus and a cancer becomes plausible when evidence from different lines of enquiry (e.g., epidemiology, pathogenesis, and molecular mechanisms) is mutually reinforcing and together provides a coherent picture that can connect the biology the virus to the characteristics of the disease. The associations of human papillomaviruses with cervical cancer and hepatitis B and C viruses with hepatocellular carcinoma are examples in which the etiologic link is clear. With SV40 and mesothelioma, the data on viral sequences in tumors is inconsistent and disputed, and serologic evidence does not support any association. The epidemiologic data do not show that documented exposures tt SV40 increase the risk of mesothelioma. It seems improbable that a single virus (which cannot be conclusively demonstrated to be present in the community) contributes to the development of such a wide variety of tumors, spanning all age groups and histologic types. The weaknesses in the evidence linking SV40 with mesothelioma are summarized in Box 11 It seems unlikely that infection with SV40 contributes to the development of human mesothelioma or any other human cancer.
Shah
Keerti V
KV
Department of Molecular Microbiology and Immunology, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe Street, Baltimore, MD 21205, USA. kvshah@jhsph.edu
D000818:Animals; D015984:Causality; D006224:Cricetinae; D006801:Humans; D008654:Mesothelioma / Q000453:epidemiology / Q000821:virology*; D010997:Pleural Neoplasms / Q000453:epidemiology / Q000821:virology*; D016133:Polymerase Chain Reaction; D013539:Simian virus 40 / Q000472:pathogenicity*