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Q: I have been diagnosed with Lynch syndrome (LS). Should I take aspirin to help prevent getting cancer?

A: For many years, researchers have observed that long-term users of aspirin have lower risks of developing colorectal cancer. Recently, the Colorectal Adenoma/Carcinoma Prevention Programme 2 (CAPP2) study found that in the long term, LS patients who took aspirin daily for over two years were less likely to develop colorectal cancer and other Lynch-associated cancers than LS patients who did not take aspirin.

The study involved a large international collaboration with over 900 LS patients. Over 500 patients took either aspirin or placebo for at least two years and were followed for an average of more than four years after stopping aspirin. Three to four years after the start of aspirin treatment, the rates of cancer between the groups started to differ. There were about half the number of colorectal cancers in patients who took high-dose aspirin for at least two years compared to the placebo group. Rates of non-colonic Lynch syndrome-associated cancers (endometrial cancer, ovarian cancer, pancreatic cancer, brain cancer, small bowel cancer, gallbladder cancer, ureter cancer, stomach cancer and bladder cancer) were also lower in people on high-dose aspirin. Further studies are in progress to help determine the best dose and duration of treatment.

Like all medications, high doses of aspirin can have serious side effects. Careful consideration is needed to determine whether taking aspirin to prevent LS-associated cancers is right for you. The following issues should be considered:

1. High-dose (600 mg per day) aspirin was used in this study. This is 7 – 8 times the dose of a baby aspirin.
2. Some people are allergic to aspirin or have aspirin sensitivity.
3. Aspirin use is associated with gastric ulcers and gastrointestinal bleeding.
4. Aspirin interferes with blood clotting and may lead to other major bleeding or hemorrhage.
5. The elderly, people with other medical problems (such as liver disease or kidney disease), or people on other medications may be at increased risk when using aspirin.

As with all medications, be sure to discuss with both your primary care physician and Lynch syndrome specialist whether aspirin for prevention is right for you.

Reference:
Lancet. 2011; 378:2081-2087