Nearly 850 patients with identified Lynch syndrome were randomly assigned to receive aspirin, resistant starch, or placebos for up to four years.  After an average of two years, 141 developed either precancerous polyps or cancer (neoplasia). There was no difference in either overall neoplasia or advanced neoplasia whether patients took aspirin or resistant starch or received a placebo.

• 66 patients or 18.9 percent of 693 patients taking 600 mg of daily aspirin developed polyps or cancer compared to 66 participants or 19 percent who received a placebo.  There was also no difference in the percentage who had an advanced adenoma or cancer — 7.4 percent versus 9.9 percent.
  
• Among 727 patients, 67 participants receiving 30 grams of Novelose resistant starch (18.7 percent) every day developed neoplasia, as compared with 68 taking a placebo (18.4 percent).  There were equal numbers of advanced adenomas and cancers in the two groups.

Henry Lynch, M.D., one of the study authors, said,

Aspirin has been used clinically for some time in patients at risk of Lynch syndrome, but our study shows that patients who take aspirin for this reason are simply wasting their time. The best protection continues to be an annual colonoscopy, beginning at age 25.

Dr. Lynch first described the inherited colorectal cancer syndrome now named for him.  People who inherit one of the genes associated with Lynch syndrome have a very high risk of getting colon cancer, often at a young age.  Inherited mutations reduce the possibility that damage to cell DNA will be repaired, leading to polyps and cancer.

John Burn M.D., who led the multinational study at 43 centers, and his team concluded,

The use of aspirin, resistant starch, or both for up to four years has no effect on the incidence of colorectal adenoma or carcinoma among carriers of the Lynch syndrome.

SOURCE: Burn et al., New England Journal of Medicine, Volume 359, Number 24, December 11, 2008.