Aspirin may protect against cancers of the mouth, throat and oesophagus, a study suggests.
Aspirin is over 100 years old
Researchers in Italy say taking aspirin regularly for five years cuts the risk of contracting these diseases by two thirds.
The findings add to growing evidence that aspirin truly is a miracle drug.
Previous studies have shown that the pill, developed more than 100 years ago, may help prevent bowel and lung cancer.
While most people take it to relieve pain, it is also widely used to protect against heart disease and even arthritis.
Reports of its latest therapeutic benefits follow a study by scientists from the Institute of Pharmacological Research in Milan.
They analysed information from three separate studies involving 965 cancer patients and 1779 people who were in hospital for other conditions.
Everyone in the studies filled in detailed questionnaires about smoking and drinking habits, diet and how often they took aspirin.
They found that people who had taken aspirin regularly for five years or more cut their chances of developing cancers of the mouth, throat and oesophagus by two thirds compared to those who didn't take the medicine.
Many of the aspirin users in the study had been taking the drug because they had been diagnosed with other health problems, such as heart disease.
The scientists believe that if people started taking the drug earlier, specifically for its anti-cancer properties, it might be possible to achieve even stronger protective effects.
However, further research will be needed to evaluate this and to track possible side-effects of long-term aspirin use.
But lead researcher Dr Cristina Bosetti hailed the findings.
"This is the first quantitative evidence that taking aspirin may reduce the risk of developing cancers in what we call the aerodigestive tract, connecting the mouth and the stomach.
"We think that aspirin may take effect by acting on an enzyme called cyclooxegenase-2, which has a role both in inflammation and the process of cancer growth.
"Our results further extend our knowledge of the health benefits of this remarkable drug and suggest that taking it could become an important way of protecting ourselves against cancer."
Dr Richard Sullivan, Cancer Research UK's head of clinical programmes, said: "Aspirin has to count as one of the greatest finds in the history of drug discovery.
"What began life as a simple painkiller now seems to have a wide range of beneficial effects for our health, and this new study adds to the evidence of a significant protective effect against cancer.
"We're not yet at the stage where we can recommend that everyone starts taking aspirin on a daily basis, as we'll need to further investigate its effectiveness and possible side-effects of long-term use.
"However, it looks as though the drug could become an important part of cancer prevention."
Each year in the UK, there are 7,250 cases of oesophageal cancer, around 4,000 cases of mouth cancer and 2,200 cases of throat cancer.
Smoking and heavy drinking are the main risk factors for all three types.
The study is published in the British Journal of Cancer.