Friday, May 24, 2013

Prostate Cancer Introduction

Table of Contents

Introduction


Prostate cancer is a malignant tumor that originates in the prostate gland. As with any cancer, if it is advanced or left untreated in early stages, it may eventually spread through the blood and lymph fluid to other organs. Fortunately, prostate cancer tends to be slow growing compared to other cancers. As many as 90% of all prostate cancers remain dormant and clinically unimportant for decades. Most older men eventually develop at least microscopic evidence of prostate cancer, but it often grows so slowly that, many men with prostate cancer "die with it, rather than from it."

Normal anatomy
The prostate gland is an organ that surrounds the urinary urethra in men. It secretes fluid that mixes with sperm to make semen.

Description of the Prostate Gland

The prostate is a walnut-shaped gland located below the bladder and in front of the rectum. It wraps around the urethra (the tube that carries urine through the penis). The central area of the prostate that wraps around the urethra is called the transition zone. The entire prostate gland is surrounded by a dense, fibrous capsule.

Functions of the Prostate Gland

The prostate gland provides the following functions:

  • The glandular cells produce a milky fluid. During sex, the smooth muscles contract and squeeze this fluid into the urethra. Here, it mixes with sperm and other fluids to make semen.
  • The prostate gland also contains an enzyme, called 5 alpha-reductase, which converts testosterone to dihydrotestosterone, another male hormone that has a major impact on the prostate.

Changes During the Lifespan

The prostate gland undergoes many changes during the course of a man's life. At birth, the prostate is about the size of a pea. It grows only slightly until puberty, when it begins to enlarge rapidly, attaining normal adult size and shape, about that of a walnut, when a man reaches his early 20s. The gland generally remains stable until men reach their mid-40s, when, in most men, the prostate begins to enlarge again through a process of cell multiplication.

Male reproductive anatomy Click the icon to see an image of the male reproductive anatomy.

Review Date: 07/26/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)