Background-Sulindac regresses colorectal adenomas in patients with familial
adenomatous polyposis (FAP), although the mechanism of polyp regression is
unclear.
Aims-To determine whether differences occur in alteration of rectal epithel
ial apoptotic index and expression of apoptosis related proteins in FAP pat
ients treated with sulindac compared with placebo.
Patients-Twenty one FAP patients; 12 had not undergone colectomy.
Methods-Patients with FAP were treated with sulindac 150 mg orally twice a
day for three months (n=10) or placebo (n=11). Colorectal polyp number was
determined and biopsies of the normal rectal mucosa were performed before a
nd after three months of treatment. Response to treatment and alteration of
the apoptotic ratio (index in base of crypt divided by index in surface ep
ithelium) were evaluated. Bcl-2, bax, p21/WAF-1, and p53 proteins were asse
ssed semiquantitatively by immunohistochemistry.
Results-Significant decreases in polyp number and in the apoptotic ratio we
re seen in patients treated with sulindac compared with controls. The mean
percentage change in polyp number from baseline was -46% in the sulindac gr
oup and +13% in the placebo group (p=0.005). Mean percentage change in the
apoptotic ratio was -8% and +25% in the sulindac and placebo treated patien
ts, respectively (p=0.004). No differences in expression or compartmentalis
ation of apoptosis related proteins were noted between treatment groups.
Conclusions-Sulindac regression of colorectal adenomas is accompanied by al
teration of the rectal epithelial apoptotic ratio with relative increase in
apoptosis in surface cells compared with the deeper crypt. The utility of
the apoptotic ratio as an intermediate biomarker for colorectal tumorigenes
is deserves further study.