ECCO/ESMO UPDATE — BERLIN 2009
Although initial reports found no reduction in polyps or cancer in people with Lynch syndrome who took aspirin and/or resistant starch supplements, longer follow-up tells a difference story.
About five years after trial participants began taking aspirin or a placebo, differences began to emerge. Even though patients in the trial only took aspirin for four years, later followup found significantly fewer colon colon cancers among those who had used aspirin, as well as fewer Lynch-related cancers overall. There were almost three times as many colon cancers in Lynch carriers who took a placebo compared to those who used aspirin.
The Colorectal Adenoma/Carcinoma Prevention Programme 2 (CAPP2) enrolled over 1,000 patients worldwide who carried a mutated gene that causes Lynch syndrome in a randomized study to compare daily aspirin use with or without resistant starch supplements to placebos. Participants in the trial took aspirin, starch supplements, or placebos for four years. An initial report in the New England Journal of Medicine found that neither aspirin or Novolose (resistant starch) made any difference in the development of polyps or cancer.
However, when the research team contacted over 600 of the original study members again, they found that, with longer follow-up, there was a significant difference in the development of colon cancer and other Lynch-related cancers. Six patients who had taken aspirin had colon cancer compared to 16 who didn’t use it. There was a reduction in endometrial cancer, as well. Overall, there were 18 Lynch-related cancers in all among the aspirin-users, compared to 31 who didn’t take aspirin during the four years of the study.
Aspirin protected the people who took it for at least 6 years after they stopped.
Participants in the trial took 600 mg of aspirin daily.
Professor John Burn, from the Institute of Human Genetics at Newcastle University in the United Kingdom,who reported the newest results of CAPP2 at the ECCO/ESMO meeting in Berlin said,
Our original design allowed for long term post trial follow-up. We have managed to track down most of those who completed the trial – around 75% of the original consent cohort – with information extending up to 10 years from randomisation. We found that, around four years after randomisation, there was a divergence in the incidence of cancers between the aspirin and placebo groups. To date, there have been only six colon cancers in the aspirin group as opposed to 16 who took placebo. There is also a reduction in endometrial cancer. This is a statistically significant result and we are delighted – all the more so because we stopped giving the aspirin after four years, yet the effect is continuing, and is directly correlated with the duration of aspirin use on the trial.
Lynch syndrome, often called hereditary nonpolyposis colorectal cancer (HNPCC), is a type of inherited cancer of the digestive tract, particularly the colon and rectum. People with Lynch syndrome have an increased risk of cancers of the stomach, small intestine, liver, gallbladder ducts, upper urinary tract, brain, skin, and prostate. Women carriers also have a high risk of developing endometrial and ovarian cancers.
Patients with Lynch-related cancers are often diagnosed at a younger age, and their tumors develop more quickly.
Concluding, Prof. Burn and his team recommended,
All those at risk of Lynch syndrome related cancer should consider long term aspirin use. Plans for a large scale randomised dose finding study of aspirin in Lynch syndrome will be presented.
SOURCE: Burn et al., European Journal of Cancer Supplements, Volume 7 Number 2, September 2009, Page 320.