The prostate gland is unique to the male reproductive system and has an important role in sexual intercourse and reproduction. This gland produces fluid that combines with sperm to create semen, enabling ejaculated sperm to swim to a woman's fallopian tubes for conception. 

The prostate is composed of glands and stroma (muscle) and has three main functions in the male body: maintaining urinary continence, reproduction and preventing bladder infections.

The internal structure of the prostate resembles a tree. Each of the lobes in the prostate has a main trunk, which drains secretions into a network of ducts that look like tree limbs. At the end of each of these ducts are structures called acini, similar to leaves attached to tree limbs. The acini are the conduit for moving secretions through the urethra. 

Of all the cancers men get, prostate cancer and melanoma (skin cancer) are the two most common. About