By Theresa Garner
HAMILTON - A cancer-causing virus which contaminated the first polio vaccines may be teaming up with asbestos to cause cancer, Waikato researchers say.
Waikato Hospital histopathologist Dr Fred Mayall and Waikato University PhD student Greg Jacobson have uncovered a link between asbestos exposure, the SV40 virus and mesothelioma, a
once-rare type of lung cancer whose prevalence has rapidly increased.
The research, published in the UK Journal of Clinical Pathology, shows that the SV40 virus is linked with mesotheliomas in people exposed to high levels of asbestos, but does not often show up in mesotheliomas in patients who have not been exposed to asbestos.
The $24,000 study was funded by Waikato Hospital and the Waikato Medical Research Foundation.
Dr Mayall said asbestos might damage the cells of the chest wall, making them vulnerable to the cancerous effect of the SV40 virus.
SV40 came from dead monkeys whose kidney cells were used to culture the first vaccines. It was injected into millions worldwide, including New Zealanders, before being detected and screened out in 1963.
Until recently, mesotheliomas - responsible for less than 1 per cent of all cancer deaths - were linked primarily to exposure to asbestos. In the past few years, overseas studies have found that around 70 per cent of cases test positive for the SV40 virus DNA.
But until now, no one had investigated factors that could predispose people to SV40-related tumours.
Dr Mayall said the public should not be alarmed.
"One should remember that, at most, only a very small percentage of immunised patients have developed cancer as the result of SV40 virus, and millions of lives were saved by polio vaccination."
Modern polio vaccination is not contaminated.
Dr Mayall said the research was probably not going to help patients with mesothelioma.
"It is more of an insight into the biology of this unusual form of cancer.
"It doesn't help you treat it, but it tells you there may be an increase in this type of cancer in the next 10 or 20 years, and that we need to find out much more about SV40 virus."
