Origin and development of carcinoma in the prostate

Detailed histologic study of 45 cancerous prostate glands in 134 autopsies provided new information on the natural history of prostatic carcinoma. Origin of carcinoma was limited to one of two histologically distinct regions, but with no apparent predilection for the “posterior lobe” or sub capsular area. Carcinoma selectively originated from active gland epithelium rather than a trophic glands, and distinctive premalignant changes accompanied its origin. Evidence from volume distribution data suggests that there are not two types of prostatic carcinoma with different biologic potential, but a single species having slow growth rate with a logarithmic growth curve. The development of carcinoma in the gland follows predictable patterns, including early involvement of the capsule and perineural spaces. The later course of tumor growth is characterized by loss of differentiation and the ability to penetrate the capsule and periurethral stroma. This suggests a gradual increase in biologic malignant potential which is closely linked to tumor size. Probably the capacity for distant metastasis is almost limited to large carcinomas, and penetration of the gland capsule may be the most important predisposing factor.