Background/aims: Sulindac, a nonsteroidal anti-inflammatory drug (NSAID), decreases the occurrence of polyps in patients with familial adenomatous polyposis (FAP). The effects of colectomy with ileorectal anastomosis (IRA) and sulindac treatment on rectal mucosa proliferation and polyp occurrence were examined in patients with FAP.
Methods: The number and size of rectal polyps were measured with colonoscopy. The labeling index, the percentage of labeled cells per crypt compartment, was assessed in rectal biopsy specimens with [3H]thymidine incorporation and autoradiography in 6 non-IRA and 14 IRA patients before and after treatment with 200 mg of sulindac/day for 60 days.
Results: The IRA patients had a lower labeling index and a decrease in the percentage of labeled cells in the upper compartment of the crypt (P < 0.01) relative to non-IRA subjects. Sulindac did not influence the labeling index and the distribution of labeled cells along the crypt. On the contrary, a dramatic decrease in the size and number of polyps was observed after sulindac treatment (P < 0.001).
Conclusions: The persistence of a abnormal mucosal proliferation after sulindac therapy, in spite of the reduction of polyp number, suggests caution in assuming a lower risk of rectal cancer in patients with FAP.