What Is Prostate Cancer?

Prostate cancer develops in the prostate, the muscular, walnut-sized gland that's located below the bladder and in front of the rectum. The prostate makes the thick fluid that’s part of semen and plays an important role in both sexual function and urinary function.

As a man ages, the cells of his prostate may change and form tumors or other growths. Cancer cells, in particular, grow out of control and spread beyond the prostate. Cancer that spreads is harder to treat. Prostate cells can create four types of growths, including:

  • Noncancerous growths: As a man ages, the prostate may grow larger. This is called benign prostatic hyperplasia (BPH). With BPH, extra prostate tissue often squeezes the urethra, causing symptoms such as trouble urinating. BPH is not cancer and does not lead to cancer.
  • Atypical cells: Some cells, called prostatic intraepithelial neoplasia (PIN), don’t look like normal prostate cells. Although they are not cancer cells, PINs may be a sign that cancer is likely to form.
  • Cancer: When abnormal prostate cells grow out of control and start to invade other tissues, they are called cancer cells. These cells may or may not cause symptoms. Some tumors can be felt during a physical exam, and some can’t.
  • Metastatic cancer: Prostate cancer may grow into nearby organs or spread to nearby lymph nodes, the small organs around the body that are part of the immune system. In some cases, the cancer spreads to bones or organs in distant parts of the body. This is called metastasis.

Prostate Cancer