What is cancer?

Cancer is when cells in the body change and grow out of control. To help you understand what happens when you have cancer, let’s look at how your body works normally. Your body is made up of tiny building blocks called cells. Normal cells grow when your body needs them, and die when your body does not need them any longer.

Cancer is made up of abnormal cells that grow even though your body doesn’t need them. In most cancers, the abnormal cells grow to form a lump or mass called a tumor. If cancer cells are in the body long enough, they can grow into (invade) nearby areas. They can even spread to other parts of the body (metastasis).

What is prostate cancer?

Prostate cancer is the most common cancer in men (not counting skin cancer) in the U.S. It tends to occur mainly in older men. In most cases prostate cancer is found before it has spread to other parts of the body. Cancer that hasn’t spread is easier to treat and cure.

Understanding the prostate gland

The prostate is a sex gland in men. The prostate is about the size of a walnut, but it can grow larger as men age. It sits below the bladder and in front of the rectum. It surrounds the upper part of the urethra. This is the tube that carries urine and semen out of the body. The prostate is part muscle and part gland. It has ducts that open into the urethra.

The prostate gland’s main purpose is to secrete a fluid that makes up most of semen. This is the fluid that carries sperm. It’s made in the gland cells of the prostate. During a man’s orgasm, the muscle parts of the prostate help to send the fluid into the urethra. It’s mixed with other fluids and sperm that were made in the testicles to form semen. The semen then leaves the body through the tip of the penis during ejaculation.

What are the different types of prostate cancer?

Cancer is tumors or growths that can grow into nearby tissues and spread to other parts of the body. Nearly all types of prostate cancer start in the gland cells. These are the cells that make the prostate fluid. These types of cancer are called adenocarcinoma. Other types of cancer can also start in the prostate. These include small cell carcinoma, transitional cell carcinoma, and sarcoma. But these types of cancer are rare. Most men with prostate cancer have adenocarcinoma.

Other types of growths can happen in the prostate. Some types of growth are not cancer (benign). These types of growths include:

• Benign prostatic hyperplasia (BPH). As a man ages, the prostate can grow larger. This is called BPH. It’s a common condition. BPH is not prostate cancer. It doesn't turn into prostate cancer. But BPH can cause the prostate to press on the urethra. This can lead to symptoms, such as trouble urinating, which might need to be treated. 

• Prostatic intraepithelial neoplasia (PIN). This is an abnormal prostate growth that may be found with a prostate biopsy. It is not prostate cancer. PIN can be low grade or high grade. Low-grade PIN is common, especially as men get older. Most healthcare providers don’t consider it to be a concern. Men who have high-grade PIN have a chance that cancer is somewhere else in the prostate.

Prostate cancer growth and spread

Prostate cancer tends to grow slowly. It can often be found and treated while it is still just in the prostate. In fact, some cases of prostate cancer may not need to be treated right away. But other cases of prostate cancer can grow quickly. The first place cancer grows in the body is called the primary site or primary tumor.

If prostate cancer is not treated and continues to grow, it can grow into other parts of the prostate. Over time it may grow outside of the prostate and into nearby tissues, such as the seminal vesicles. When cancer spreads to other parts of the body, this is called metastasis. Once the cancer has grown outside the prostate, it can spread to nearby lymph nodes. These are bean-sized glands all around the body that are part of the immune system. If prostate cancer spreads to distant parts of the body, most often it goes to the bones first. It may also spread to other organs, such as the lungs, liver, or brain.

Talk with your healthcare provider

If you have questions about prostate cancer, talk with your healthcare provider. Your healthcare provider can help you understand more about this cancer.