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Friday 11 November 2011


I have been forced to think a lot about percentages recently.  It seems to be all about percentages with Breast Cancer.  Percentage chance of survival after a lumpectomy on a Stage 3 cancer - 69%.  Radiotherapy adds around another 5%.  Chemotherapy takes that up another 10-15%.  If you have the type of cancer that responds to Tamoxifen, your chances are even better. 

My one and only chemotherapy session ended up with me having a severe allergic reaction.  Not to the drugs (1-10% chance of reaction) or to the antibiotics (7%) but to water (1 in 250,000,000 - looks more dramatic that way).  A second session of chemotherapy had a 50% chance to reversing this reaction.  It had a 50% chance of an even more adverse reaction.  That particular percentage was too scary for me.  No more chemo.  So a 74% chance that I won't get breast cancer again.

An interesting fact about chemotherapy.  It is only effective as a preventative in 12% of patients.    Medical science is not advanced enough to specify which 12% will benefit.  But it does mean that 88% of patients receive absolutely NO benefit from chemotherapy at all.  Just saying....

The other percentage that interested me was from a speech made by Dr Thomas Insel, NIMH at the F.E.A.S.T. conference about advances in the understanding of brain disorders and in particular, eating disorders.  A whole new world to understand.

"I think this comment about remembering this is multi factorial and probably many different disorders and they are not from the same cauldron and they don't require the same treatments.  We do have to recognise that we are still in an early stage and part of why I do what I do.....  We are at the 2% level and there is an awful lot we still have to learn.  We are at a very early stage of trying to understand these (disorders).  I think we are on a different path by saying that we have got to understand these from a biological as well as a psychological perspective and sometimes biological pieces of this, we may not see and psychological changes may be happening in a stealth way and requires a bio marker or something if you think there seems to be a problem.  That seems to be true in some other areas.  So all I am suggesting is we have to be open and we have to be humble at this point that there is a lot we don't know."

1 comment:

  1. Percentages and statistics are hugely complicated when applied to an individual - because they're based upon population measures. So we can take a large population, or a sample from a population of breast cancer patients with stage X cancer and state the odds based upon probability for the population or the sample, but the individual is an individual and may show an individual or idiosyncratic response.

    I like statistics, but they can be confusing. Think of it like this. If you toss a coin 10 times, the probability of it coming up either heads or tails is 50%. But if you try this exercise yourself, you'll find that the response varies each time.

    I agree with what Insel says about EDs. That paragraph above sums it up for me.