The NDRS genomics team has been working closely with Professor Sir John Burn and his CAPP2 clinical trial team at Newcastle University. The CAPP2 trial investigated the long-term effects of aspirin and resistant starch on cancer incidence in around 1000 patients with LS. We used our NDRS pseudonymisation technology to link the CAPP2 clinical trial records to gold standard English and Welsh cancer registration data on cancer incidence. This enabled every patient in the trial to be followed up comprehensively for between 10-20 years, depending on when they started on the trial.
In a previous publication in The Lancet, the trial showed that taking a daily aspirin for two years could halve the incidence of colorectal cancer over the next decade in people with LS. A recent follow up paper was published in Cancer Prevention Research; this looked at the resistant starch aspect of the trial. Although resistant starch had little impact upon colorectal cancer itself, it prevented 60% of upper gastrointestinal malignancies in people with LS.
Any carbohydrate that escapes digestion in the upper gut is good for bowel health. If it can be fermented by gut bacteria, it’s called ‘resistant starch’. Resistant starch is found in a range of foods such as oats, slightly green bananas, breakfast cereal, cooked and cooled pasta and rice, peas and beans. The dose used in the trial is equivalent to eating a daily banana. We don’t know exactly how resistant starch works, but it probably alters the mix of bacterial species living in the gut – the microbiome – encouraging the ‘good bacteria’ to predominate. The microbiome is also known to impact upon the function of the immune system – and cancers in people with Lynch syndrome have certain characteristics that make them more visible to the immune system – so potentially there is a link there.
Both aspirin and resistant starch are cheap, readily available substances, with a good safety profile. Both were statistically significant as preventative treatments in Lynch syndrome on ‘intention to treat’ – this means that everyone in the trial was included in the analysis, even if they dropped out early: that’s the highest bar for a clinical trial. It’s a great example of using NDRS data to support cutting edge clinical research into potentially lifesaving interventions for those people most vulnerable to cancer.
