A growing body of evidence suggests that taking aspirin may reduce an individual's chances of developing colorectal cancer and perhaps other malignancies, but whether that evidence is strong enough to outweigh the risks of prescribing it to millions of healthy people is the subject of debate.
"The efficacy of aspirin in preventing colorectal cancer has been made obvious by more than twenty years of research," said Professor Robert Benamouzig from the Department of Gastroenterology, Avicenne Hospital, Bobigny, France.
"In 2010, researchers published the 20-year follow-up of five pooled randomized trials that assessed the effect of aspirin on colorectal cancer incidence and mortality. The study of more than 14,000 patients found that daily aspirin at any dose reduced risk of colorectal cancer by 24 percent and associated deaths by 35 percent after a delay of about 8 to 10 years," said Benamouzig.
"In these trials, the reduction of colorectal cancer rates was in essence a side-effect of treatment. None of them had such a reduction as their primary outcome. Nevertheless, the evidence that aspirin is effective for preventing these colorectal cancers is very strong," he said.
"NSAIDs and in particular aspirin are very promising in secondary prevention of colorectal neoplasia, however their role in primary prevention is still not proven," said Professor Nadir Arber of the Tel Aviv Sourasky Medical Center in Israel. "This means that the majority of the population does not need, and is not going to benefit from aspirin use. Having said that, specific high-risk populations definitely can benefit from aspirin intake, including people with hereditary non-polyposis colorectal cancer, familial adenomatous polyposis, existing colorectal cancer or adenoma. In the future based on genomic profile, we would be able to identify people who are at high risk of developing colorectal cancers and who might benefit from aspirin therapy."
Before aspirin can be used for preventing these cancers, we need to develop means of identifying people who are going to benefit from the drug without developing side-effects, Arber said. Risks of taking aspirin include gastrointestinal bleeding and intracranial hemorrhage. "We need a study that will measure overall morbidity and mortality and not efficacy and toxicity in a single organ or disease such as cardio-vascular disease," he said.
MEDICA.de; Source: European Society for Medical Oncology (ESMO)