Only men have a prostate. Its job is to make the fluid that carries sperm out of your penis when you have an orgasm. As you age, your chances of getting cancer of the prostate rise. This disease is common among older men.

If you or someone close to you has been diagnosed with prostate cancer, you may feel frightened and anxious about what lies ahead. Deciding on the best treatment can be difficult, as researchers know little about which treatments work best. Be sure to take your time and don't rush into a decision. Learn all you can about the condition and how it is treated, and talk to your doctor about the options open to you.

To understand prostate cancer and its treatments, you first need to know where the prostate is and how it works. The symptoms of the disease will also make more sense if you know how the prostate is linked to other parts of your body.

The prostate is a small, solid gland, about the size of a chestnut. It makes the milky fluid that comes out of your penis when you have an orgasm. The fluid from the prostate helps keep your sperm healthy and also helps them to swim.

The prostate is mainly made up of special cells that make the fluid that you ejaculate. (Cells are the tiny building blocks that make up all the tissues in your body.) The prostate fluid drains into a network of thin tubes called ducts. These ducts carry the fluid into the urethra. All around the cells in the prostate gland is supporting tissue (called stroma) that gives the gland its structure.

Your prostate also has a thick layer of muscle along the section next to the urethra. This helps pump the fluid into the urethra. Most of your prostate is covered with a thin but tough sheath of muscle and fibrous tissue, as well as a layer of blood vessels that carry oxygen and food to the prostate cells.

Inside the prostate, there are more blood vessels and also lymphatic vessels. Lymphatic vessels carry a fluid known as

 

 

 

 

 

lymph fluid
Lymph is a clear or whitish liquid that is collected from all over the body and flows through the lymphatic vessels and lymph nodes (also called glands). It contains proteins and fats, some red blood cells, and many white blood cells, especially lymphocytes. Lymphocytes help the body fight infection.

 

 

 

 

 

lymph, which is important in protecting the body against infection. Both blood vessels and lymphatic vessels play a role in the spread of cancer, as they can carry cancer cells from the prostate to other parts of the body.

To help the sperm along their way, the prostate has to make and release its fluid at the right time during sexual activity. When you become excited during sex, sperm travel from your testicles through a series of tubes to the part of the urethra that the prostate wraps around.

On the way, the sperm collect some jellylike liquid from the

 

 

 

 

 

seminal vesicles
The seminal vesicles are two glands that sit like small bunches of grapes on either side of the prostate. These glands make some of the fluid that comes out when men ejaculate (push out semen from their penis) at the moment of orgasm.

 

 

 

 

 

seminal vesicles and then travel through the prostate in the

 

 

 

 

 

ejaculatory duct
The ejaculatory duct is a passage that carries fluid from the seminal vesicles to the penis, where the fluid joins the sperm to make semen. The duct runs through the prostate.

 

 

 

 

 

ejaculatory duct.

When the sperm arrive in the urethra, nerves in the prostate trigger the muscle here to flex. As the muscle flexes, it squeezes the network of tubes in the prostate, so that they pump out fluid into the urethra where it mixes with the sperm to become semen. The semen flows out of your body through your penis when you ejaculate.

The prostate also makes sure that your semen flows in the right direction. The prostate partly controls a ring of muscle that flexes as your semen is carried through your penis. This shuts off the urethra, so that semen cannot flow back up it into the bladder.

The prostate fluid contains foods, such as sugar and calcium, which help keep your sperm healthy. It also makes a substance that doctors call prostate-specific antigen, or PSA. PSA helps the semen stay liquid, so the sperm can swim freely.

When something goes wrong with the prostate, it's common for large amounts of PSA to enter your bloodstream. If there is cancer in the prostate, for example, this can disrupt the network of tubes there and cause more PSA to leak into the blood. A blood test to check how much PSA is in your blood can indicate your chances of having prostate cancer.

 

 

 

 

 

Source:
Scher HI.
Hyperplastic and malignant disease of the prostate.
In: Braunwald E, Hauser SL, Fauci AS, et al. Harrison's principles of internal medicine. 15th ed. McGraw Hill, New York, U.S.A.; 2001.

 

 

 

 

 

²

You may have heard of this test, or had it already. To learn more, see How do doctors diagnose prostate cancer?

To make a diagnosis, doctors think of the prostate in three different parts, which they call "zones." You don't need to know these zones to understand your prostate, but it may help you talk with your doctor if you know what they mean.

Doctors once described these different parts as "lobes," but most now describe the prostate by zones. You may sometimes see the term "lobe" used to describe the right and left sections of the prostate gland.

 

 

 

 

 

Source:
Scher HI.
Hyperplastic and malignant disease of the prostate.
In: Braunwald E, Hauser SL, Fauci AS, et al. Harrison's principles of internal medicine. 15th ed. McGraw Hill, New York, U.S.A.; 2001.

 

 

 

 

 

²

 

 

 

 

 

Source:
Sinnatamby CS.
Male internal genital organs.
In: Last's anatomy: regional and applied. 10th edition. Churchill Livingston, Edinburgh, UK; 1999.

 

 

 

 

 

³

 

 

 

 

 

Source:
Carroll PR, Lee KL, Fuks ZY, et al.
Cancer of the prostate.
In: DeVita VT, Hellman S, Rosenberg SA. Cancer: principles and practice of oncology. 6th edition. Lippincott, Williams and Wilkins, Philadelphia, U.S.A.; 2001.

 

 

 

 

 

¹

Hormones are chemicals produced by one part of the body to travel through the bloodstream and have an effect on another part. Sex hormones are important for sexual growth and development.

Your sex hormones are very important to the prostate. They cause it to grow during puberty (the time when your sex organs mature) and they also help it make the fluid that carries sperm out of your body.

The sex hormones in men are known as androgens, and the main one is testosterone. Testosterone is mainly made by the testicles, but a smaller amount is also made by your adrenal glands, which lie on top of your kidneys. Testosterone travels through the bloodstream to the prostate where an enzyme (a substance that speeds up chemical reactions) called 5-alpha-reductase changes it into a more active form of the hormone, called dihydrotestosterone. Dihydrotestosterone has two jobs: It makes the prostate grow during puberty and it enables the prostate to make fluid that carries your sperm.

The prostate often starts growing again when you get older. Doctors don't know why this is, but it is probably linked to hormone changes. When the prostate gets bigger, this condition is called benign prostatic hyperplasia (BPH). "Benign" means noncancerous and "hyperplasia" is an increase in the number of normal cells. This condition is not cancerous but may lead to bothersome symptoms such as having to urinate often and urgently, dribbling urine, straining to pass urine and having to urinate frequently at night.

When your body's cells are healthy, they grow and divide to form new cells as your body needs them. When cells grow old and die, new cells take their place.

Sometimes this process breaks down. New cells form too rapidly, when the body doesn't need them, and old cells don't die when they should. You get prostate cancer when some of the cells in your prostate begin to grow out of control. The extra cells can form a mass of tissue called a growth or tumor.

Most doctors believe that prostate cancer cells slowly change in appearance and in how fast they divide for many years before true cancer starts. These precancer changes have been called prostatic intraepithelial neoplasia (PIN).

 

 

 

 

 

Source:
Carroll PR, Lee KL, Fuks ZY, et al.
Cancer of the prostate.
In: DeVita VT, Hellman S, Rosenberg SA. Cancer: principles and practice of oncology. 6th edition. Lippincott, Williams and Wilkins, Philadelphia, U.S.A.; 2001.

 

 

 

 

 

¹ Researchers think around half of all men have PIN and that cancer may develop in some of them after 10 to 20 years. Once researchers find out more about PIN, they might be able to predict the chance of a man developing prostate cancer.

Most prostate cancers start in cells that are on the side of the prostate that presses against the rectum (the peripheral zone of the prostate).

 

 

 

 

 

Source:
Scher HI.
Hyperplastic and malignant disease of the prostate.
In: Braunwald E, Hauser SL, Fauci AS, et al. Harrison's principles of internal medicine. 15th ed. McGraw Hill, New York, U.S.A.; 2001.

 

 

 

 

 

² This is why doctors will often look for signs of cancer by examining your prostate through the wall of your rectum.

If your cancer hasn't spread outside of the prostate gland, doctors call it clinically localized cancer. Sometimes the cancer cells in the prostate can keep growing and spread to other parts of the body nearby. Your doctor may call this locally advanced cancer.

If your cancer does spread, it is likely to go to these areas.

 

 

 

 

 

Source:
Carroll PR, Lee KL, Fuks ZY, et al.
Cancer of the prostate.
In: DeVita VT, Hellman S, Rosenberg SA. Cancer: principles and practice of oncology. 6th edition. Lippincott, Williams and Wilkins, Philadelphia, U.S.A.; 2001.

 

 

 

 

 

¹

The cancer cells can be carried to other, more distant parts of the body through the blood vessels or lymphatic vessels in the prostate. This spread is called

 

 

 

 

 

metastasis
This happens when cancer cells spread to parts of the body that are far away from the primary tumor. The cancer can travel through the bloodstream, lymph system or other fluids. New tumors may form in another area of the body as a result.

 

 

 

 

 

metastasis. This is a more advanced and serious form of cancer.

When cells from prostate cancer spread to another part of the body, such as a lung, it is still called prostate cancer (not lung cancer).

Lymphatic vessels are small tubes that that reach every part of your body, a bit like your blood system. They collect fluid (called

 

 

 

 

 

lymph
Lymph is a clear or whitish liquid that is collected from all over the body and flows through the lymphatic vessels and lymph nodes (also called glands). It contains proteins and fats, some red blood cells, and many white blood cells, especially lymphocytes. Lymphocytes help the body fight infection.

 

 

 

 

 

lymph) from tissues all over the body, including your prostate, and take it to your

 

 

 

 

 

lymph nodes
Lymph nodes (also called glands) are small, bean-shaped lumps that you cannot usually see or easily feel. They are located in various parts of the body, such as the neck, armpit and groin. Lymph nodes filter the lymph fluid and remove unusual things, such as bacteria and cancer cells.

 

 

 

 

 

lymph nodes (small lumps packed with special cells called lymphocytes that fight infection). Lymph nodes trap unwanted bacteria and waste products in the fluid to prevent them from getting into your bloodstream.

Cancer cells in your prostate may be picked up by the lymph and carried to the lymph nodes in your pelvic cavity (the space between your hip bones and the lowest part of your back). The cancer cells may continue growing there or travel to other parts of your body through your lymphatic vessels. You can't tell for sure if the cancer has spread to the lymph nodes in your pelvic cavity unless your doctor removes at least one of them to take a closer look. This may be done if you have surgery to remove a cancerous prostate.

Cancer cells can also get into blood vessels in the prostate and travel around the body. This is why men with prostate cancer are sometimes given drugs that treat the whole body. This is called systemic treatment.

Although the cancer can travel anywhere in your body, it usually spreads to bones such as your hips and lower spine. Doctors aren't sure why prostate cancer cells are drawn to bone cells. In fact, there is a lot of uncertainty about how prostate cancer cells spread.

Just like normal cells in the prostate, cancer cells need male hormones to help them grow at first. Some treatments can block the action of hormones in the prostate and stop the cancer from growing. To learn more, see our section on hormone therapy.

Cancer cells also need a new blood supply to provide them with oxygen and nutrients so they can keep growing. The way cancer cells make this new blood supply is a process called angiogenesis. Drugs that stop this process (angiogenesis inhibitors) are being investigated as a treatment for prostate cancer.

Your doctor will not be able to tell you why you have cancer. For most men, no cause can be found. Instead, your doctor may talk about risk factors, which are things that make it more likely that certain men will develop the disease. The most well-known risk factors are:

For more information, see Risk factors for prostate cancer.

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