Monday, 28 February 2011

The dividing line between last hope and false hope

There was a very sad story in the latest edition of our local free magazine, Swindon Link. It concerns 27-year-old Tami Brown who has been fighting cancer for seven years and has now being told it's terminal. She is hoping to raise £5,000 to take a last hope therapy. We are told about the new 'High-Dose Intravenous Vitamin C therapy':
Based on research by Noble [sic] Prize winner Dr Linus Pauling there is a lot of reported success in the USA and New Zealand.
 There are several problems with this statement. Taking it at face value you might think that medical researcher Dr Linus Pauling has recently won a Nobel Prize for his successful therapy. The reality is a little different. Pauling did indeed win the Nobel Prize - twice, in fact. Once the peace prize and once for chemistry. He was a chemist, not a medical doctor. In the 1970s he became interested in the idea that high doses of vitamin C could cure the common cold, and later that it could have a positive effect on cancer. At the time this was just a speculative idea - he had no personal involvement in work demonstrating this.

In clinical trials in the 1980s, this treatment was shown to be no better than placebo, though Pauling always questioned the results as the trial had not been intravenous. He died in 1994, so has no recent part in this story.

There has since been some evidence that high doses of vitamin C do slow the growth of some cancers in mice. the effect is small, however - there are many other substances that would have a bigger effect. Unfortunately the 'lots of reported success' mentioned in the article does not appeal to have a scientific basis. To quote a scientific analysis (see link below):
If high dose intravenous ascorbate has antitumor activity in humans, that activity is almost certainly quite modest at best, and to achieve even such modest antitumor activity definitely requires incredibly high doses of ascorbate. Once again, I point out that any other experimental drug requiring such high plasma concentrations and high doses to achieve such a modest antitumor effect would probably garner very little interest from anyone, even if it were a potentially patentable product of big pharma.
It's a really difficult one. If this were a totally unsubstantiated treatment, like the suggestion that cancer can be treated by homeopathy, then it would be easy to say 'there's no point' - and it would probably be illegal to say that the treatment could cure cancer. But this is less clear cut. When does a last hope become a false hope?

You can read the full Swindon Link story here, visit Tami Brown's website here, and read a detailed analysis of the science here, emphasing how limited the effect of vitamin C was in the mice trial. Then, perhaps you can make your own mind up.

3 comments:

  1. There's an odd thing, though: the placebo effect has been reported to cure people even of terminal cancer. So, if the person in question really believes this might be a cure, it might become one.

    That was one of the "things that don't make sense" in New Scientist a while ago, if I remember correctly.

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  2. so sad :( interestingly im reading "Bad Science by Ben Goldacre" that covers Vitamin C therapy at the moment.

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  3. While possibly true, Pelo, it would be nice to use a less intrusive placebo.

    Thanks, Sarah - I had forgotten this is in Ben's excellent book. You can see more about it here http://www.popularscience.co.uk/reviews/rev419.htm

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