Aspirin is seemingly becoming one of the centerpieces of cancer research with a new study now suggesting that the drug improves survival rates of patients with tumours situated throughout the gastrointestinal (GI) tract.
The study carried out in The Netherlands is the first one to analyse the survival rates of patients with GI tumours all along the tract. Researchers believe that their major study involving nearly 14,000 patients could pave way for more detailed studies and new insights regarding the use of aspirin in GI cancer.
Researchers analysed data from 13,715 patients who had been diagnosed with a GI cancer between 1998 and 2011. They linked the data from these patients to drug dispensing information from PHARMO, the Institute for Drug Outcomes Research based in Utrecht, and showed that an association between aspirin use after a cancer diagnosis and overall survival (OS) does exist.
Researchers say that their analysis showed that there was a significant increase in overall survival among patients who did take aspirin compared to those who did not.
Patients using aspirin after their diagnosis had a chance of survival twice as high than that of those who did not use it in the same circumstances. The beneficial effect of aspirin use on survival was seen in patients with GI tumours after adjusting for potential confounding factors such as sex, age, stage of cancer, surgery, radiotherapy, chemotherapy and other medical conditions or disorders.
Trial co-ordinator Martine Frouws, MD, from Leiden University Medical Centre, Leiden, The Netherlands, explains that while all other observational studies use the ‘intention to treat’ method analysing aspirin’s effect, they analysed each separate prescription per patient, and therefore were able to achieve a more exact estimate of the effect of aspirin on cancer survival.
A multicentre, randomised, placebo-controlled trial is currently investigating the effect of a daily dose of 80 mg aspirin on OS of elderly patients with colon cancer in The Netherlands. Through this study, researchers hope that they will then be able to expand the trial to include further sites in the GI tract, and provide convincing proof that more patients will benefit from aspirin treatment.
“Given that aspirin is a cheap, off-patent drug with relatively few side-effects, this will have a great impact on healthcare systems as well as patients,” says Dr Frouws.
The scientists believe that the beneficial effect of aspirin in cancer is due to its antiplatelet effect. Platelets are a blood component whose function is to stop bleeding by clumping and clogging blood vessel injuries. Circulating tumour cells (CTCs) are thought to hide themselves from the immune system with the help of the clothing of platelets that surround them. Aspirin inhibits platelet function and therefore allows the immune system to recognise CTCs and eliminate them.
Dr Frouws and her colleagues have suggested that not only can aspirin prevent disease, but low dose aspirin is important as an adjunct therapy for gastrointestinal cancers.
The appropriate dosage and duration of aspirin use and risk/benefit ratios of aspirin use remain to be determined but, in the area of precision medicine, genetic information and blood and/or urinary biomarkers may help in tailoring treatment to those who will benefit most, while limiting adverse effects.
