crabsallover highlights in red and my comments in bold orange
crabsallover has paid $31 for Janusz Jankowski paper cited by Peter Rothwell et al: stored on my hardrive: aspirin-cancer-consensus-jankowski.pdf
Expert opinion: aspirin and cancer – the unanswered questions
In the light of today’s headlines about aspirin and cancer, we spoke to one of our leading scientists Professor Janusz Jankowski, who’s running a clinical trial – AspECT – looking at whether aspirin can prevent oesophageal and bowel cancer. Here are his opinions and concerns about the latest findings:
Aspirin’s ability to prevent cancer, especially cancers of the digestive system (oesophagus, stomach and bowel cancers) is well known.
But before we can recommend that people take aspirin, there are several important things to learn about whether long-term low-dose aspirin use is beneficial overall.
How common are side-effects?
Aspirin has several serious side effects. Most importantly, aspirin can increase the chances of developing stomach ulcers – which can cause bleeding. In people over 75, this can be fatal. The true frequency of aspirin-related stomach ulcers varies depending on the method used to measure it – it can be anywhere from 0.1 to 2 per cent of people taking aspirin, every year. Peter Rothwell somewhere mentioned the 1/1000 or 0.1% figure.
Who will benefit?
Secondly, because we’re all genetically different, and have different lifestyles, aspirin probably doesn’t prevent cancer in everyone who takes it. A reasonable estimate, based on the available research, is that about a quarter (25 per cent) of people will benefit – but this figure may be as low as a fifth (20 per cent). So the majority of people taking aspirin may not in fact benefit from it.This ‘aspirin resistance’ seems to be widespread, and we don’t yet know what causes it. So we don’t know who should take aspirin. To clarify this, we need large genetic studies to discover who will benefit from low-dose aspirin.
What dose?
Thirdly, we don’t know what dose of aspirin is best. While the current paper has looked at 75mg of aspirin we don’t know that 150 or even 300mg isn’t better. This is vital – the commonest reason drugs don’t work is the dose is wrong.Peter Rothwell research says 75mg per day gives 21% reduction in cancer.
How long should you take it for?
Fourth, we don’t know how long a person has to take aspirin to get a protective effect. The current paper indicates an unusually rapid response for this: five years. This is unique and in many ways doesn’t fit with how we understand cancer develops.Note: The Peter Rothwell et al paper is 'unique' and 'doesn't fit with how we understand cancer develops'.
What has been done by Cancer Research UK in this area?
The trial I work on – AspECT – was specifically designed to measure rates of oesophageal cancer, bowel cancer and deaths from heart disease.
The trial is split into four groups:
- people only given a low-dose proton pump inhibitor
- people only given a high-dose proton pump inhibitor
- people given a low-dose proton pump inhibitor with 300mg aspirin
- people given a high-dose proton pump inhibitor with 300mg aspirin
To date, the team behind the trial haven’t revealed any obvious differences between these four groups.
The study looked at trials that focused on heart disease rather than cancer, and that might have biased the results.
For example, the number of deaths from cancer of the digestive system was just 182 out of almost 20,000 patients. There were only 23 deaths from oesophageal cancer. That’s a very small number to be trying to draw firm conclusions from.
Janusz Jankowski
Reference:
Rothwell, P., Fowkes, F., Belch, J., Ogawa, H., Warlow, C., & Meade, T. (2010). Effect of daily aspirin on long-term risk of death due to cancer: analysis of individual patient data from randomised trials The LancetDOI: 10.1016/S0140-6736(10)62110-1
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