Sunday, 18 January 2015

4. Is Bad Luck to blame for most Cancers?

   

It is perhaps presumptuous for me cross swords with the distinguished Professor Bert Vogelstein of the John Hopkins University School of Medicine. He it was, you may remember, who was recently quoted as stating that "All cancers are caused by a combination of bad luck, the environment and heredity".
     His comment was supposedly to clarify the published results of his team's research finding that random mutations, which occur in DNA when cells divide, are responsible for two-thirds of adult cancers, while the remaining third are linked to environmental factors or defective inherited genes.
     There are surely provisos to Professor Vogelstain's statement however which were either left unsaid, or were omitted by the press, which prefers to paint word images in stark black and white for headline value and ignore the important shades of grey in the small print.
     It is that dangerous use of the word "ALL" in the published statement that worries me - and many others. For example 30 years ago cervical cancer might have been lumped with the group of cancers caused by "bad luck" whereas it is now well established that infection with the human papilloma virus causes this disease.  Indeed there are other examples, such as the hepatitis viruses HBV and HCV, which are the main cause of liver cancer and there is also a virus known to cause leukaemia in adults. Clearly this begs the question: “Are there viruses, as yet unknown, which can cause cancer if left undiagnosed and untreated?" This is not an easy question to answer since many of these types of viral infection produce few symptoms in the majority of people, which makes them hard to detect. Furthermore, the virus can be cleared during the time period between acquiring the infection and developing the cancer which can take as long as 50 years. The virus may be gone but the damage it caused persists and contributes to development of the malignancy, leading to cancer – what is known as the “Hit-and–Run” hypothesis. 
     At present approximately 20% of all human cancers are known to be caused by infections but we do not yet know whether this is an underestimate.  I bet that there will be future occasions where research will show that the answer is "Yes"!
     Similarly, while we now know that there is a strong correlation between aspects of poor lifestyle, (smoking/alcoholism/obesity/food choice/sedentary habits, or a lethal combination thereof), and some cancers, little research has been done on the positive effects of nutrition and diet on the prevention of some of those cancers now dismissively binned as 'bad luck'.
     Meanwhile, until cancer prevention rather than cure becomes the norm, we must stress the need to focus more resources on finding ways to detect such cancers at an early, curable stage, while charities such as Caring Cancer Trust, The Humane Research Trust and the Cancer Prevention Research Trust fund researchers like Drs Ian and Lynne Hampson in their continuing work to find those elusive infectious causes of cancer and, hopefully, non-invasive cures. 



Drs Lynne and Ian Hampson, PhD. Photo Caring Cancer Trust


 Dr Ian Hampson PhD, Reader in Viral Oncology, University of Manchester, writes in response: 

      The thing about Professor Vogelstein is that what he says is true but it is not the whole story since, as you rightly point out, viruses and other environmental factors, (some obviously dietary), combine with the genetic hand we have been dealt to promote the development of cancer. If you can prevent or limit exposure to the former it has got to improve our chances. For example worldwide cervical cancer kills 275,000 women every year and we know that, if you cure the virus, women hardly ever get the disease.
      The problem with nutrition and diet is that we keep getting it wrong. It seems that the diet that people are exposed to in early life, and even in utero, fixes the goalposts for what our bodies regard as normal. If we step outside this by a good measure problems can ensue.


Further Reading
utube : Dr Ian Hampson PhD discusses recent cancer research breakthroughs.

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