Abstract PR-14: Regression of rectal polyps in familial adenomatous polyposis patients with freeze-dried black raspberries

Abstract

Abstract PR-14 Familial adenomatous polyposis (FAP) is a dominantly inherited disease characterized by the early onset of colonic polyposis and a risk of colon cancer of nearly 100% by the age of 40. The traditional management of FAP is colectomy followed by lifelong endoscopic surveillance of the rectum and removal of rectal polyps. Our laboratory has reported on the ability of freeze-dried black raspberry (BRB) powder to prevent chemically-induced cancer in the rodent colon. Administration of BRB powder at 2.5, 5 and 10% in a synthetic diet to rats treated with the carcinogen, azoxymethane, reduced the development of colonic adenocarcinomas by 50 - 80%. BRBs prevent cancer in rodents by reducing cell proliferation, inflammation and angiogenesis, and by stimulating apoptosis and differentiation. We also showed in a Phase I clinical trial that BRB powder is well tolerated by humans when administered in a slurry of water at 45g/day for 7 days. Based upon these results, we undertook the present study to determine if BRB might regress rectal polyps in FAP patients. Fourteen FAP patients who had undergone a colectomy were treated with BRB daily for a period of nine months. Seven patients received BRB powder (20g/3x/day) orally in a slurry of water plus two suppositories (each composed of 700 mg BRB) that patients inserted into the rectum one hour before bedtime. The other seven patients were randomized to receive an oral placebo plus the two rectal suppositories. Rectal polyp counts were taken at time zero and after nine months of BRB treatment. The number of rectal polyps was reduced by a median of 43% at nine months overall including a median reduction of 59% in patients treated by both routes and 36% in patients treated with the suppositories only. Polyps and aberrant crypt foci were collected both before and after berry treatment, and molecular studies are underway to determine the mechanism(s) for BRB-induced rectal polyp regression in FAP patients. (Supported by NCI grant CA103180 and USDA grant 38903-03560). Citation Information: Cancer Prev Res 2008;1(7 Suppl):PR-14.