Fighting cancer with aspirin

In addition to its known ability to block an enzyme called cyclooxygenase (COX), aspirin also reduces the formation of blood vessels that fuel developing tumors, it is reported in the current (October) edition of a leading scientific journal.

Without new blood vessels – formed through a process called angiogenesis – tumors cannot grow beyond the size of a pea. With this information, researchers can pursue new lines of investigation that could ultimately yield an entirely new type of cancer-fighting drug.

In the study, Dr Helen Arthur and colleagues at Newcastle University Medical School show that salicylate, an ancient remedy found in plants and closely related to aspirin, also reduces the formation of new blood vessels, an important part of tumor development.

The findings, which appear in the October 2006 issue of The Journal of the Federation of American Societies for Experimental Biology (FASEB), provides important clues to how aspirin works in cancer and in inflammation.

'Aspirin has always been touted as a wonder drug,' said Gerald Weissmann, MD, Editor-in-Chief of The FASEB Journal, 'and this study shows that we are still learning about the many actions of this amazing drug.'

Dr Arthur said: 'We know from previous studies that low doses of aspirin taken over long periods can reduce the risk of cancer – by as much as 50 per cent in the case of bowel cancer.

'Aspirin seems to work against tumour formation in several ways, one of which is to restrict the blood supply. Tumours attract a blood supply by releasing growth factors that cause nearby blood vessels to grow into the tumour.

'We conducted experiments which involved applying various doses of aspirin to cells, which normally line the inside of blood vessels.

'Our experiments showed that low doses of aspirin had an effect on these cells which tended to cancel out the effect of the growth factors from the tumours.

She added: 'High doses of aspirin are toxic and we would like to stress that anyone suffering from cancer should not take aspirin unless they are advised to do so by a doctor.'