In this paper, studies by a large series of independent investigators are reviewed with regard to the basic structure and function of the prostate in an attempt to examine their relationship to prostatic cancer etiology. These studies demonstrate that the functional activities of the prostate involve secretion, transport, and reabsorption of a variety of materials into and out of the glandular lumen and that these activities are directly related to the basic structural organization of the gland. These functional activities are constantly occurring in the prostate even under basal (ie, nonejaculating) conditions. Due to these functional activities, the prostatic fluid in the glandular lumen is a complex mixture of a variety of components derived, not only from the synthetic activity of the glandular epithelial cells of the gland itself, but also from the blood serum. The levels of these components are continuously modulated, not only by the frequency of active ejaculation, but also, under basal conditions by the continuous interaction with the glandular prostatic cells lining the acinar lumen and ducts. A concept is presented that the initiation and/or promotion of prostatic carcinogenesis may well involve the chronic modulation/interaction of the prostatic glandular cells with their lumenal fluid.