ON THIS PAGE: You will find some basic information about this disease and the parts of the body it may affect. This is the first page of Cancer.Net’s Guide to Prostate Cancer. To see other pages, use the menu on the side of your screen. Think of that menu as a roadmap to this full guide.
Cancer begins when normal cells in the prostate change and grow uncontrollably, forming a mass called a tumor. A tumor can be cancerous or benign. A cancerous tumor is malignant, meaning it can spread to other parts of the body. A benign tumor means the tumor will not spread.
About the prostate gland
The prostate is a walnut-sized gland located behind the base of a man’s penis, in front of the rectum, and below the bladder. It surrounds the urethra, the tube-like channel that carries urine and semen through the penis. The prostate's main function is to make seminal fluid, the liquid in semen that protects, supports, and helps transport sperm.
Types of prostate cancer
Prostate cancer is a malignant tumor that begins in the prostate gland. Some prostate cancers grow very slowly and may not cause symptoms or problems for years. However, most prostate cancer cells make excessive amounts of a protein called prostate specific antigen (PSA). PSA is also found in higher-than-normal levels in men with other various prostate conditions in addition to prostate cancer. Those conditions include benign prostatic hyperplasia (BPH), which is an enlarged prostate, and prostatitis, which is inflammation or infection of the prostate. See the Risk Factors and Prevention  section for more information.
Prostate cancer is somewhat unusual, compared with other types of cancer, because many tumors do not spread from the prostate. Often, even metastatic prostate cancer can be successfully treated, allowing men with prostate cancer to live with good health for several years. However, if the cancer spreads to another part of the body through a process called metastasis, and cannot be well controlled with treatment, it can cause pain, fatigue, and other symptoms.
More than 95% of prostate cancers are a type called adenocarcinomas. A rare type of prostate cancer known as neuroendocrine cancer or small cell anaplastic cancer tends to spread earlier but usually does not make PSA. Read more about neuroendocrine tumors .
Many times, when a man develops prostate cancer much later in life, it is unlikely to cause symptoms or shorten the man’s life, and aggressive treatment may not be needed. For this reason, early detection for prostate cancer with PSA testing in men who don’t have symptoms of the disease is controversial.
Looking for More of an Overview?
If you would like additional introductory information, explore these related items. Please note these links will take you to other sections on Cancer.Net:
- ASCO Answers Fact Sheet : Read a one-page fact sheet (available as a PDF) that offers an easy-to-print introduction to this type of cancer.
- ASCO Answers Guide:  This 44-page booklet (available as a PDF) helps newly diagnosed patients better understand their disease and treatment options, as well as keep track of the specifics of their individual cancer care plan.
- Cancer.Net Patient Education Video : View a short video led by an ASCO expert in this type of cancer that provides basic information and areas of research.
- Cancer.Net En Español: Read about prostate cancer in Spanish  or read a one-page ASCO Answers Fact Sheet  in Spanish. Infórmase sobre cáncer de próstata en español  o una hoja informativa de una página, Respuestas sobre el cáncer .
To continue reading this guide, use the menu on the side of your screen to select another section.