Phase II A Trial of Curcumin Among Patients With Prevalent Subclinical Neoplastic Lesions (Aberrant Crypt Foci)

PRIMARY OBJECTIVES: I. To determine mean percentage change from baseline in prostaglandin E2 (PGE2) within ACF pre and post 30 days of curcumin administration at a specified dose. SECONDARY OBJECTIVS: I. To determine mean percentage change from baseline in 5-hydroxy-eicosatetraenoic acid (5-HETE) within ACF pre and post 30 days of curcumin administration at a specified dose. II. To determine mean percentage change from baseline in PGE2 and 5-HETE within comparison normal mucosa pre and post 30 days of curcumin administration at a specified dose. III. To quantify corresponding enzyme changes in the cyclooxygenases (COX-1, COX-2,) and lipoxygenase (5-LOX) protein abundance. Semi-quantitative changes in these proteins will be measured by western blotting and correlated with changes in prostaglandins and leukotrienes respectively. IV. Document changes in total ACF number. V. Determine proliferation by Ki-67 IHC in rectal mucosa pre and post therapy and correlate with changes in ACF number and size. VI. Determine curcumin concentration in rectal mucosa after 30 days therapy and correlate with PGE2 and 5-HETE changes described above. VII. Measure glutathione peroxidase (GPx) activity within the colon pre and post therapy as an indirect marker of reduced oxidative stress within the colonic epithelium. VIII. Ensure safety of all participants during course of study investigation. IX. Determine the curcumin concentration in plasma before and after treatment. OUTLINE: This is a multicenter, nonrandomized, uncontrolled study. Patients receive 1 of 2 doses of oral curcumin once daily. Treatment continues for 30 days in the absence of unacceptable toxicity or disease progression. Blood and tissue biopsies are obtained by sigmoidoscopy or colonoscopy at baseline and at day 30 for correlative biomarker studies. The change in prostaglandin E\_2 (PGE\_2) is assessed by enzyme immunoassay, 5-hydroxy-eicosatetraenoic acid (5-HETE) by high-performance liquid chromatography, cyclooxygenases (COX-1 and COX-2) and 5-lipoxygenase (5-LOX) by western blotting, Ki-67 by immunohistochemistry, and glutathione peroxidase (GPx) by spectrophotometric assay. After completion of study therapy, patients are followed at 1 week. PROJECTED ACCRUAL: A total of 48 patients will be accrued for this study.