Aspirin - truly a wonder drug ?

[Nik]

Up until now the main reason for taking aspirin was prevention of vascular events. But there's been a lot in the press over the last 12 months about it's potential use as "chemoprevention" since a study done earlier this year found 75mg daily aspirin cut the risk of dying from all cancers by 34%. Just last week there was another study in patients with a hereditary form of colorectal cancer which found that 600mg daily cut the risk of development of the cancer, with a greater reduction in those taking the drug longer than 2 years.
Of course the risks and benefits need to be weighed and the author of the most recent study has said that more needs to be done to decide the suitable dose to take and duration of treatment (and a further study in the colorectal trial is planned), but both authors have said they have started taking preventative aspirin. Thoughts anyone ?

[Asterix]

Aspirin is no longer used in primary prevention anyway as you know due to the risks outweighing the benfits. Furthermore, I think we would need further studies before establising the greatness or downfall of such a drug. I know it has been shown to be effective in bowel cancer but surely a healthy diet in general would go towards helping this.

[Nik]

True, but those who have been identified as having a hereditary form may already be doing everything they can including dietary measures. The addition of a daily dose of aspirin may then be an attractive option to potentially reduce the risk further. In 4 previous placebo RCT's, aspirin was shown to reduce the risk of adenoma formation, the precursor to almost all colorectal cancers, in pt's with a history of adenoma or colorectal cancer. The trial for patients with Lynch syndrome was designed with colorectal cancer as the endpoint, but interestingly it showed that initially after an average treatment period of 29 months aspirin didn't reduce the risk. Follow up studies (which were reported last week) of about 2.5 years showed that fewer pts developed colorectal cancer on aspirin. It's not conclusive or definitive but for that population group at least it provides strong evidence. With regards to general chemoprevention, if trials can be conducted and benefit shown, who knows ?

[Asterix]

pretty interesting that but yes more studies would have to be carried out. I guess it is an attractive option for those individuals. The only major problem would be certain patient groups who are intolerable due to gi irritation and previous history of such bleeds which can be quite a large proportion.

[Nik]

On the subject of GI side effects, the follow up study stated that there were no data on adverse effects post-intervention but during the treatment period adverse effects were similar between aspirin and placebo. A bite vague really - no mention of GI bleeds specifically, but if lower doses can be shown to have a protective effect then the evidence may become harder to ignore.