Benefits and risks of aspirin in the context of its anti-cancer potential

Aspirin has been reported to have the potential to prevent selected cancers of the digestive tract. Aspirin also reduces the risk of serious vascular diseases in patients already at higher risk of them. A team led by researchers from the University of London has published their assessment of the risks and benefits of aspirin by analysing previous reports of the effects of aspirin.

Aspirin is a powerful drug with powerful adverse effects, including bleeding into the digestive tract or brain, causing some forms of asthma, exacerbating gout and causing rare but serious complications in children under 16 years of age ...

See more on this in Spanish on the BBC World Service website.

Below is an English version of the BBC World Service report:

" Myth and reality of aspirin to prevent disease

Writing

BBC Mundo

Aspirin is one of the world's best selling drugs. More than two thousand years ago, Hippocrates, the Father of Medicine, discovered the active ingredient in aspirin, which he extracted from the willow plant, and used to soothe fevers and headaches.

But it was not until 1897 that the German Felix Hoffman developed the drug as such. More than a century later, aspirin, acetylsalicylic acid, is one of 10 generic best sellers in the world, with annual sales of about $ 1.7 billion.

Besides being a recognized analgesic, aspirin has gained ground as way to prevent certain diseases. Multiple studies have highlighted its benefits in preventing cardiovascular disease and various cancers.
However, taking aspirin regularly involves significant risks. BBC News spoke to several experts to discuss how and when it is advisable to take a dose of this medicine each day.

Cardiovascular Benefits

Taking a daily dose of aspirin is a method widely used to prevent cardiovascular disease in people who have had this disorder already.

Mike Knapton, associate medical director at the BHF, told the BBC that for people who have had heart attacks, angina, some types of stroke and diseases of the arteries, a low dose of aspirin a day can prevent the occurrence of new episodes. This practice is well established and several studies have demonstrated these benefits.

The reason is that aspirin inhibits platelet adhesion in blood vessels reducing blood clotting.  But research also points that the drug may not prevent cardiovascular events in healthy people.  Rather, "the risks of taking a daily dose of aspirin outweigh the benefits of taking it in the case of people who have never had this kind of disorders," said Dr. Mike Knapton.

Reduction of cancer

In recent years, several studies have also pointed to the benefits of the drug as a way to prevent certain types of cancer. Experts also point out that aspirin increases the risk of bleeding. In fact, Peter Elwood, a British expert who participated in the scientific team that first showed the benefits of this analgesic in cardiovascular disease states that "the future is aspirin in reducing certain types of cancer."

Recent research by Queen Mary University of London, argues that for people between 50 and 65 years, a dose of daily aspirin can significantly reduce the risk of developing colon, esophageal and stomach cancer.
"This study showed a 35% reduction in cases of colon cancer and 40% in the number of deaths from this disease," Julie Sharp, Director of the Health Information Department of the British charity Cancer Research UK told the BBC.

"In relation to stomach cancer and esophagus, a reduction of 30% in the number of cases and between 35% and 50% in deaths was recorded, "said the expert. The study recommends that people between 50 and 65 take a dose of 75 and 100 grams of aspirin for at least 5 years, preferably 10 years.

Significant risks

But some studies in the UK have indicated that in some cases, taking the drug may have more risks than benefits. One of the side effects of this drug is the possibility of internal bleeding, including brain. Experts agree that a daily dose of aspirin helps prevent cardiovascular problems in people who already suffer from these disorders.

As he explained to the BBC, Donald Singer, professor of clinical pharmacology in the department of medicine at Yale University in the United States, "as a result of its blood thinning effect, aspirin can cause bleeding, for example in people who have a stomach or intestinal ulcer, and in some cases it can also cause bleeding in the brain. "

Research from Queen Mary University of London recognizes these risks and stresses that in the case of persons 60 years of age who take a daily dose of aspirin for 10 years, the risk of bleeding in the digestive tract increased from 2.2% to 3.6%, and in a small proportion of these cases (5%), can lead to death. " It is important that in each patient assessment is done to establish who can take aspirin and who should not".

Julie Sharp, of the British charity Cancer Research UK said the risk increases significantly for people over 70 years.

But to what extent do the risks outweigh the benefits of aspirin?

Here is a point on which not all experts agree. "I have no doubt that the balance is in favor of taking aspirin for people over 50 years," Professor Peter Elwood told the BBC. He noted that, although the risk of bleeding is increased, there is no evidence aspirin is associated with fatal bleeding. "The evidence suggests that there is minor bleeding, but not fatal."

But a study from the University of London published in 2012 concluded that the medicine, taken daily, can do more harm than good to a healthy person.
Julie Sharp notes that precisely because it is not known with certainty who may suffer side effects, "it is important that in each case testing done to establish who should take aspirin and who is not."

Consult your doctor

The active ingredient of aspirin has been used to treat headaches for centuries. With so many studies highlighting the benefits of aspirin, thousands of people in several countries take the drug to prevent disease before presenting with any symptoms, something that according to Professor Donald Singer, a member of the British Pharmacology Society, can be very dangerous. "It's very important that people are aware of the risks and consult your physician" before taking long term aspirin treatment.

He explained that people who suffer from indigestion, or asthma, or who have gout or who are taking other drugs that inhibit blood clotting are at increased risks of the side effects of aspirin.

And that also applies to children under 16 years of age. "One might be tempted to give aspirin to a child, in the case of families with a history of colon cancer, such as prevention. But this is very dangerous because in the case of minors, a daily dose may cause liver damage."

It is also important not to take more than the dose of 75 mg, or a quarter of a standard dose of aspirin.

The benefits of aspirin to prevent disease in specific cases are well established, but experts insist that consulting a doctor is essential to reduce risks of adverse effects."

EACPT Awards to be presented at August Geneva Congress

The EACPT has announced its awards for 2013, to be presented at the 11th EACPT Congress in Geneva 28th - 31st August 2013. 

The Special Award for services to the EACPT goes to Professor Michael Orme, who co-founded the EACPT 20 years ago in 1993. Professor was EACPT founding secretary then Chairman and played a major role in growing EACPT into a major international organisation representing all clinical pharmacology societies in Europe and their over 4000 clinical pharmacologist members.

The  2013 EACPT Scientific Award goes to Dr David Devos from the Department of Medical Pharmacology at the Université Lille Nord de France. The EACPT Scientific Award is for the report by Dr Devos, using methylphenidate as a new approach to treating Parkinson's disease. 

The paper, for which Dr Devos was corresponding author, was published in the July 2012 issue of 
the high impact international journal -  Lancet Neurology. The prize includes a 2000 € award.

The 2013 Lifetime Achievement Award of the European Association of Clinical Pharmacology and Therapeutics goes jointly to Professor Sir Michael Rawlins and to Professor Carlo Patrono, for their outstanding contributions to the national and international benefits of clinical pharmacology for medicine, health care and patient safety.

 EACPT website. 

Official EACPT journal - Clinical Therapeutics. 

Painkillers and hearing loss in women?

@HealthMed Researchers from Boston in the USA have reported that pain-killer use increases risk of hearing loss in women. Sounds worrying but worth looking at what the study involved and asking the obvious questions: are the findings credible and can they be generalised beyond the population in the report?

This was a prospective observational study of around 62,000 women in the US Nurses Study, the overwhelming majority of whom were of Caucasian origin. Information was collected on use of three types of painkiller - ibuprofen, acetaminophen (paracetamol in the UK), and aspirin. Nurses were following for 22 years on average.

What did they find? The rate of reported hearing loss from all causes was high at one in six over the entire population in the study. For those using painkillers, there was no link with hearing change with occasional use (once or less per week) or with aspirin whatever the reported frequency if use. For ibuprofen or acetaminophen (paracetamol), regular use for 2 days a week or more was linked to increased risk of hearing loss. The highest relative reported increase in risk was 1in 4 (24%) excess hearing loss linked to use of ibuprofen on at least 6 days a week. The authors state they are unaware of the specific mechanisms linking hearing loss to these medicines in their study.

What potential weaknesses are there in the study?
These include:
-   Noise exposure is an important cause of hearing loss; and of headaches, an obvious reason to be taking painkillers. There was no information available on noise exposure as a confounding cause of hearing loss. The authors acknowledge that is an important flaw in their study.
- Hearing loss was self-reported and severity of hearing loss not measured.
- No information was given on the dose of pain-killers used.
- Taking painkillers regularly from 2 days a week to every day suggests underlying medical problems which may themselves have had an impact on hearing. Co-morbidity accounting for the pain-killer use was not clear.
- Oddly there was no consistent increase in risk of reported hearing loss with increasing numbers of days a week of painkiller use: similar hearing loss reported with paracetamol 6 or more days a week, as for 2 days a week but more hearing loss when taken taken 4 or 5 days a week
- In this study aspirin was not associated with hearing loss but would be expected to be based on previous studies, including studies in men. This raises questions about the accuracy of data collection.

Are the findings generalisable to people outside the study group?
- These were mainly Caucasian origin women who were nurses working in the USA. It is unclear whether similar findings would have occurred in other occupational groups, ethnic groups or other countries. However there are biochemical mechanisms by which all these drugs, including aspirin, could affect the hearing system. Therefore it would be premature to suggest that aspirin would be a safe alternative painkiller with regard to hearing.

Further research is needed to explore whether these findings are due to painkillers or co-incidental, and if confirmed, to find out who is at particular risk. For the present, any risk appears relatively low and linked in this study only to women taking selected painkillers (ibuprofen or paracetamol) for several days each week over long periods. Any long-term use of pain-killers should be discussed with a medical advisor or pharmacist. People who have unexplained hearing loss and are currently on these medicines at least 2 days a week for long periods should seek advice from their medical advisor, pharmacist or hearing consultant.