The humble aspirins case for being a wonder drug just got stronger. Three studies published in the latest issues of The Lancet show the analgesic to have anti-cancer properties,along with a role in prevention of distant metastasis (spread from one part of the body to another) of the disease. The studies build a case for inclusion of the drug in cancer treatment protocol.
Because of its blood-thinning quality,aspirin is already recommended for cardiovascular patients.
One of the new studies examined patient data from 51 long-term randomised controlled trials involving 77,549 patients. Researchers at the University of Oxford found that after three years of daily aspirin use,the risk of developing cancer was reduced by almost 25 per cent when compared with a control group not taking aspirin. After five years,the risk of dying of cancer was reduced by 37 per cent among those taking aspirin.
A second paper that analysed five large randomised controlled studies in Britain found that over six and a half years on average,daily aspirin use reduced the risk of metastatic cancer by 36 per cent and risk of adenocarcinomas common solid cancers including colon,lung and prostate cancer by 46 per cent.
Daily aspirin use also reduced the risk of progressing to metastatic disease,particularly in patients with colorectal cancer,the studies reported.
A third paper by Andrew T Chan and Nancy R Cook of Harvard Medical School compared the findings of the observational studies and the randomised trials of aspirin.
There is an urgent need for clinical trials of treatment regimens incorporating aspirin,Dr Peter M Rothwell,a professor of clinical neurology at the University of Oxford,who led the first two studies,said. What really jumps out at you in terms of prevention is the striking 75 per cent reduction in oesophageal cancer and a 40 to 50 per cent reduction in colorectal cancer,which is the most common cancer right now. In terms of prevention,anyone with a family history would be sensible to take aspirin.
The studies show a lot of promise because we never knew these things earlier,says P K Julka,professor of clinical oncology at AIIMS. According to him,the anti-inflammatory properties of aspirin and its role as inhibitor of prostaglandins (hormome-like substances) may explain the findings of the studies. Professor Julka cautions that more trials were needed before aspirin could be made a part of the treatment protocol.
However,long-term use of aspirin as in patients with a cardiovascular condition is not without its share of risks.The drug is known to trigger bleeding in the gastrointestinal tract,and the risk of that goes up as a patient grows older. Past studies have also suggested that the drawbacks of daily use may outweigh the benefits,particularly in healthy patients.
It is a little difficult to comment on the role of aspirin in arresting metastasis without larger studies. And trials will be difficult unless the subjects are of a certain age group and chosen very carefully, warns Dr Ashok Vaid,consultant oncologist at Medanta.
The note of warning notwithstanding,doctors remain upbeat. Says Dr Kusum Verma,senior consultant cytopathologist at Sir Gangaram Hospital,The results look very promising though obviously more studies are required.