The purposes of this study is, (A) to examine the association of carcinoma and morphologic manifestations of aging within the prostate gland in necropsies, and (B) to investiate by pretested questionnaires whether dietary and/or lifestyle habits of American blacks are related to the high incidence of prostatic carcinoma. The initial findings in our investigation are as follows. Prostate glands from 508 necropsy cases, 171 from Ibadan, Nigerian and 337 from Washington, D.C. were reviewed and analyzed for severity of arterial medial fibrosis, intimal thickening, muscle proliferation and the presence or absence of sclerotic atrophy of glands in the outer prostate. The vascular changes and the sclerotic atrophy of the glands were more severe in the U.S. specimens as compared to the African specimens (p less than 0.05). Sclerotic atrophy of glands in the outer prostatic area was more severe in prostates with microcarcinoma than in prostates without carcinoma (p less than 0.05). Twenty age-matched patients and controls have been analyzed for epidemiologic and nutritional variables so far. Associations between prostate cancer and the following epidemiologic variables were detected: 1. lower urinary tract infections 15 or more years before diagnosis of cancer (p less than 0.05), 2. exposure to irrigation, bougie and dilatation treatment of lower urinary tract infections (p less than 0.05), 3. family history of cancer (p less than 0.05) and 4. professional, paraprofessional and skilled occupation (p less than 0.01). In the nutritional study the following observations were made: The consumption of citrus fruits and juices was more common in controls than in prostate cancer patients (p less than 0.05). The consumption of butter milk was less common in controls as compared to prostatic carcinoma patients (p less than 0.05). Controls consumed more tabasco sauce than patients (p less than 0.05).