Aspirin and cancer prevention suggested, but needs proof

Underscores the need for a large clinical trial in older adults, says ASPREE Principal Investigator

 

ANNOUNCEMENT

Research findings by Rothwell et al, (two published in ‘The Lancet’ and one in ‘The Lancet Oncology’) to hit the media today are suggesting that daily aspirin can be used to help prevent and possibly treat cancer.

Need for a clinical trial

Professor John McNeil, Principal Investigator of the ASPREE trial in Australia said the research highlights the need for a clinical aspirin trial in older adults because:

• The new research findings suggest that overall, aspirin might help prevent and delay the spread of some cancers in the body.
• The papers do not tell us whether aspirin reduces the incidence and spread of cancer in older people (or in fact any particular age group), although ASPREE will help answer this.
• The papers are based on a meta-analysis, which means an analysis of 51 different studies published between 1968 and 2010. These participants varied in age, health, the dose of aspirin and the duration of the studies.
• The average age in one study was 62 and unknown in other papers.
• Of 25,000 people studied, the actual number of cancer deaths prevented was relatively small – 12 deaths per 1000 placebo versus 9 per 1000 in aspirin groups.
• The majority of participants included in the studies were male.
• The only side-effect of aspirin that this research focused on was  ‘major’ bleeding outside the brain (in other words gastro-intestinal bleeding) and not other potential side effects, such as anaemia, which may affect an older person’s quality of life.
• None of the studies investigated aspirin and dementia.
• ASPREE is one of the first large international trials to establish whether the benefits of aspirin (including cancer prevention) outweigh the risks specifically in people aged 70 and over.

Benefits must be weighed against risks

Prof McNeil said the research, which was conducted by a team at the University of Oxford in the UK, was encouraging but urged caution.

He said the effects of long-term aspirin use, which could increase the chance of internal bleeding in the stomach, intestines and brain, needed to be weighed against potential benefits, especially in older adults.

“Knowledge about whether aspirin should be used for prevention in the elderly will come only from clinical trials that measure all of the potentially positive and negative effects of the drug in that age group,” Prof McNeil said.

“Only ongoing research into the effects of aspirin across all ages and populations can give definitive answers as to aspirin’s potential health benefits and its risks, including cancer.”

ASPREE is the largest public, primary prevention clinical trial of low-dose aspirin in older Australians and will follow the health and well-being of participants for five years in Victoria, Tasmania, SA, NSW and the ACT and in the USA.

The papers were called:

1. Short-term effects of daily aspirin on cancer incidence, mortality, and non-vascular death: analysis of the time course of risks and benefits in 51 randomised controlled trials
2. Effect of daily aspirin on risk of cancer metastasis: a study of incident cancers during randomised controlled trials
3. Effects of regular aspirin on long-term cancer incidence and metastasis: a systematic comparison of evidence from observational studies versus randomised trials

We encourage participants with concerns to please contact the ASPREE team on 1800 728 745 (toll free from a landline).

Updated 2.04.2021