Cancer is a disease in which cells grow in an abnormal way. Normally, the cells divide in a controlled manner. If cells keep dividing when new cells are not needed, a tumor forms.
A tumor can be benign or malignant. A benign tumor is not cancer. It will not spread to other parts of the body. A malignant tumor is cancer. Cancer cells spread and cause damage around them. They can also enter the lymph and blood streams. This makes it easier to spread cancer to other parts of the body.
Normal Anatomy and the Development of Prostate Cancer
The prostate gland is part of the male reproductive system. It's located in the pelvis, under the bladder and next to the rectum. The walnut-sized gland surrounds the urethra. This is a tube that carries urine out of the bladder. The prostate makes and stores seminal fluid, which is needed to keep sperm healthy. During ejaculation, it releases the seminal fluid into the urethra. Here, it mixes with sperm to make semen.
Cell division and cell death are normal. It’s meant to replace old or damaged cells. Male hormones (called androgens) are needed for the prostate to work as it's supposed to. This also keeps the prostate at a normal size. As men age, the prostate changes and grows, while androgen levels go down. These may cause changes in the cells that can lead to prostate cancer. Tumors that grow in the prostate can cause problems with the urinary system. The most common are urgency, frequency, and a weak stream. If it grows beyond the prostate, cancer can spread into nearby structures such as the rectum or bladder. This can also cause problems with how they work as well. It can also spread to lymph nodes or blood vessels and carry cancer to other sites in the body. The most common sites for prostate cancer to spread are the lymph nodes and the bones.
Types of Prostate Cancer
Prostate cancer is based on how it looks in a lab and where the cancer starts. The types are:
- Adenocarcinoma—Starts in the cells that make seminal fluid inside the prostate. This type makes up nearly all prostate cancers.
- Sarcoma—Rare type that starts in the connective tissues that support the prostate.
- Neuroendocrine—Rare type that starts in the endocrine cells that are linked to hormones.
- Transitional cell—Rare type that starts in the tissue that lines the inside of the prostate gland.