Aspirin may double survival in cancer patients

A daily dose of aspirin may double the life expectancy of patients with cancers affecting the gastrointestinal tract, a new study has claimed.
This is the first time that survival data from patients with tumours in different gastrointestinal (GI) locations have been analysed at the same time. Previously, only one type of cancer, usually colorectal, was studied.
Trial co-ordinator Martine Frouws, from Leiden University Medical Centre in The Netherlands, and her team analysed data from 13,715 patients who had been diagnosed with a GI cancer between 1998 and 2011.
By linking the data to drug dispensing information from PHARMO, the Institute for Drug Outcomes Research based in Utrecht, the team was able to show an association between aspirin use after a cancer diagnosis and overall survival (OS).

They found there was a significant increase in OS among patients who did take aspirin compared to those who did not.
In total, 30.5 per cent of patients used aspirin pre-diagnosis, 8.3 per cent were solely post-diagnosis users, and 61.1 per cent had not taken aspirin at all.

The most common sites for tumours were colon (42.8 per cent of patients), rectum (25.4 per cent), and oesophagus (10.2 per cent).
Median follow-up time for all patients was 48.6 months, with 28 per cent of patients surviving for at least five years.
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.
"Through studying the characteristics of tumours in patients where aspirin was beneficial, we should be able to identify patients who could profit from such treatment in the future," Frouws said.
At present, a multi-centre, randomised, placebo-controlled trial is studying the effect of a daily dose of 80 mg aspirin on OS of elderly patients with colon cancer in The Netherlands.
"Given that aspirin is a cheap, off-patent drug with relatively few side-effects, this will have a great impact on health-care systems as well as patients," said 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.