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Study finds possible role for aspirin as treatment for colon cancer

BMJ 2012; 344 doi: http://dx.doi.org/10.1136/bmj.e2988 (Published 24 April 2012) Cite this as: BMJ 2012;344:e2988
  1. Zosia Kmietowicz
  1. 1London

Researchers are planning to investigate the role of aspirin as a treatment for colon cancer after finding an association with reduced mortality among patients who took the drug after diagnosis.

The use of aspirin as a treatment for colon cancer could prove especially useful for elderly patients who are not suitable for chemotherapy, say the researchers from the Netherlands, whose study is published in the British Journal of Cancer (doi:10.1038/bjc.2012.101).

Previous studies have shown that taking a daily aspirin for several years can help to lower the risk of a number of cancers developing, including bowel and oesophageal cancers. But the present study focused on the therapeutic effects of aspirin.

The observational study of 4481 patients with colorectal cancer between 1998 and 2007 found that, in the subgroup of 1219 who took aspirin daily for any length of time after their diagnosis, mortality from colon cancer was 23% lower than in patients who did not take aspirin (adjusted rate ratio 0.77 (95% confidence interval 0.63 to 0.95)).

In patients who took aspirin for nine months mortality from colon cancer was 30% lower (adjusted rate ratio 0.7 (0.46 to 0.81)).

Most patients were prescribed 80 mg or 30 mg aspirin a day to protect against cardiovascular disease.

The study also found that patients who took aspirin both before and after their diagnosis benefited but to a lesser extent than those who took aspirin only after diagnosis, with a mortality reduction of 12% (adjusted rate ratio 0.88 (0.83 to 0.97)). Researchers said that this might be because patients who took aspirin and still got bowel cancer could have had a particularly aggressive form of tumour that did not respond as well to aspirin.

Aspirin did not reduce mortality among the small group of patients with rectal cancer. And other non-steroidal anti-inflammatory drugs did not have the same therapeutic effects as aspirin.

Colorectal cancer is the third commonest cancer in the United Kingdom, with around 41 000 new diagnoses a year. It is the second most common cause of death from cancer after lung cancer—in 2010 around 16 000 people in the UK died from the disease.

One of the authors, Gerrit-Jan Liefers, who is based at the Leiden University Medical Centre in the Netherlands, said that their findings are very similar to those of a 2009 JAMA study (2009;302:649-658; doi:10.1001/jama.2009.1112), which increased his confidence that the effects of aspirin were real.

“Our findings could have profound clinical implications. In this study we showed the therapeutic effect of a widely available, familiar drug that costs mere pennies per day,” he said. “It’s possible that some older people may have other health problems which mean that they are not well enough to have chemotherapy. Bowel cancer is more common in older people, so these results could be a big advance in treatment of the disease, particularly in this group. But we need further research to confirm this.”

The research team has applied for funding for a randomised placebo controlled trial specifically targeting the over-70s to examine the effects of aspirin as an adjuvant to chemotherapy in colon cancer.

Notes

Cite this as: BMJ 2012;344:e2988