A study involving almost 14,000 cancer patients has linked increased survival rates with regular aspirin use. The research involved sufferers of various forms of gastrointestinal tumors and found that patients who starting to use aspirin after they had been diagnosed doubled their chances of survival.

Led by scientists from the Netherlands' Leiden University Medical Centre, the study analyzed data of 13,715 gastrointestinal cancer patients. This form of illness pertains to the group of cancers affecting the digestive system, with the colon, rectum and oesophagus the most common tumor sites among the subjects in this study. Of the subjects, 30.5 percent had used aspirin before being diagnosed, while 8.3 percent began taking it after the fact, and 61.1 percent had not used aspirin at all.

The team found that those who started using aspirin after their diagnosis were twice as likely to be alive after four years as those who did not. This observation was made after adjusting for factors such as sex, age, stage of cancer, types of treatment and other medical conditions.

As for how the cheap painkiller might be countering the work of the cancer cells, the scientists have a theory. They point to the antiplatelet effect of aspirin, which they believe makes the tumor cells more visible to the immune system. The platelets in our blood carry out the task of clogging blood vessel injuries to stem blood flow, but in doing so it is possible they are offering a hiding place for circulating tumor cells to operate in. And because aspirin inhibits platelet function, it may be lifting the veil on these dirty dealings and better enabling the immune system to destroy them.

The cancer-fighting properties of aspirin have been explored for some time. In 2012, researchers developed a new aspirin compound that curbed the growth of 11 different types of human cancer cells in culture. Earlier studies have suggested that aspirin can reduce the risk of dying when it comes to gastrointestinal cancers, but the Dutch researchers say this is the first time data from patients with tumors in different gastrointestinal locations has been analyzed at the same time.

A randomized, placebo-controlled trial is now underway whereby the researchers are treating elderly colon cancer patients with a daily dose of 80 mg of aspirin to investigate the overall survival rates. The team also hopes to study tumor material from patients with the purpose of determining who would benefit from aspirin treatment, and build on its findings by expanding the trial to cover other sites along the gastrointestinal tract.

The researchers are presenting the results of the study this week at the 2015 European Cancer Congress in Vienna, Austria.