Effects of ASA on Prostate Tissue

Inclusion Criteria: * May be on watchful waiting for low grade prostate cancer who are scheduled for biopsy to monitor disease. * Have a previous diagnosis of prostatic intraepithelial neoplasia (PIN)or atypical small acinar proliferation (ASAP) before either second biopsy or even is second biopsy still has PIN or ASAP and they are to undergo a third biopsy. * Extended-sector (at least 10 cores) prostate biopsy performed within three months of enrollment. * Prostate tissue frozen at time of prostate biopsy (UW #04-3963-V 01) * PSA less than 15. * Performance status 0 or 1 by the ECOG scale. * Ability to understand and willingness to sign an informed consent document. * Willingness to take 325mg enteric coated aspirin daily and abstain from any other NSAID, aspirin product, or COX-2 inhibitor during the study. * Willingness to abstain from any hormonal or herbal preparation indicated to affect hormone levels during the study. Exclusion Criteria: * Any prior or concurrent hormonal therapy, chemotherapy, or investigational agents. * Use of Finasteride, Dutasteride, saw palmetto, or any herbal/nutritional preparation indicated to affect hormone levels. * Use of 325mg aspirin three or more times a week. * Use of NSAIDS three or more times a week. * Use of NSAIDs, Cox-2 inhibitors and/or aspirin for 6 weeks prior to study enrollment and during the 3-month intervention. * Known bleeding disorder. * History of gastrointestinal bleeding. * History of peptic or duodenal ulcer disease. * History of stroke. * History of serious bleeding, including but not limited to hemorrhagic stroke, epistaxis, hematuria, hematochezia, hemorrhoidal bleeding requiring cauterization. * Uncontrolled hypertension. * Aspirin sensitivity or allergy. * Liver disease with known ascites, varices, clotting disorder, or liver function test \>1.5 normal. * Anemia, thrombocytopenia, prolonged INR. * Elective surgery scheduled during 3-month intervention. * Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, CHD presently requiring a revascularization procedure, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements.