Prostate Cancer Facts

What Is Prostate Cancer?



Prostate cancer is a disease in which cells in the prostate start growing abnormally and uncontrollably.

The prostate is a walnut-shaped organ that contributes fluid to semen and helps expel semen during ejaculation.

Almost all prostate cancers are adenocarcinomas (which originate from the glandular cells of the prostate) and most are slow growing. However, they may cause symptoms that require timely interventions, such as restricting urine flow or sexual function.

Prostate cancer accounts for about 15% of all new U.S. cancer cases, affecting one in eight men. This type of cancer is the third-most common cancer in the United States, and it's the second-most common type of cancer affecting men, after skin cancer.

Stages of Prostate Cancer

Knowing the stage of the prostate cancer helps your care team understand which prostate cancer treatment options may be best for you. After a prostate cancer diagnosis, your doctor may recommend one or several tests to determine the cancer stage. Two of the measurements used to calculate the stage of prostate cancer are the Gleason score and testing for prostate-specific antigen, or PSA.


Stage 1: At this stage, the cancer is confined to one side of the prostate and is slow growing. It has not reached the lymph nodes or other parts of the body. It may have low Gleason or PSA scores.

Stage 2: In stage 2A, 2B or 2C, the cancer may have spread to both sides of the prostate gland, but no further. Stage 2 tends to have higher Gleason and PSA scores. 

Stage 3: Divided into stages 3A, 3B and 3C, this is when the cancer may have spread to both sides of the prostate or to nearby tissues, but not to the lymph nodes.

Stage 4: At stage 4A, the cancer has often spread to the nearby lymph nodes. Stage 4B means the cancer has spread to distant lymph nodes or other parts of the body.

The three stages of prostate cancer development

Types of Prostate Cancer

Up to 99% of prostate cancers are a type called adenocarcinoma, which forms in the cells lining the inside the prostate gland. There are two types of adenocarcinoma of the prostate – also referred to as glandular prostate cancer.

Acinar adenocarcinoma (conventional adenocarcinoma) is by far the more common. It usually starts near the rectum, at the back of the prostate. In many cases, it is first detected during a digital rectal examination (DRE).

Prostatic ductal adenocarcinoma (PDA) is a much rarer, more aggressive cancer type that can be harder to diagnose. It develops in the tubes and ducts of the prostate gland. PDA often develops at the same time as acinar adenocarcinoma.

There are some other extremely rare types of prostate cancer. Although these types are diagnosed from time to time, together, they account for less than 1% of prostate cancers.

Transitional cell carcinoma (or urothelial cancer) is a cancer that spread to the prostate after starting in the urethra or bladder, or vice-versa.

Carcinoid tumors can develop in the cells that release hormones from the prostate gland. 

Small cell carcinoma is an aggressive type of neuroendocrine cancer that can develop in the small round cells of the neuroendocrine system.

Squamous cell carcinoma is an incredibly rare, fast-growing kind of prostate cancer that begins in the flat cells covering the prostate gland.

Prostate sarcoma (or soft-tissue prostate cancer) is a type of cancer that develops in the muscles and nerves surrounding the prostate.

What Causes Prostate Cancer?

Prostate cancer occurs when cells in the prostate mutate and begin to grow uncontrollably. These new cells can then form a cancerous tumor. There are both environmental and inherited factors involved in the development of prostate cancer.

Prostate Cancer Risk Factors

Risk factors are things that can increase your risk of developing cancer. Some risk factors for prostate cancer include:

  • A family history of prostate cancer
  • Conditions such as prostatitis, inflammation of the prostate and benign prostatic hyperplasia (BPH), a noncancerous enlargement of the prostate gland
  • A diet high in red meats and high-fat dairy and low in fruits and vegetables
  • Obesity
  • Age: Approximately 60% of cases are diagnosed in men over 65.
  • Race and ethnicity: African American men and Caribbean men of African ancestry are more likely to be diagnosed with prostate cancer.

Is Prostate Cancer Genetic?

Another risk factor for prostate cancer are hereditary gene mutations, which are passed on from parents to children. Research suggests that up to 10% of prostate cancer diagnoses may be caused by gene mutations.

The most common mutations related to prostate cancer are the BRCA1 (breast cancer 1) or BRCA 2 (breast cancer 2) genes or having Lynch syndrome, which is also referred to as hereditary nonpolyposis colorectal cancer (HNPCC).

What Are the Symptoms of Prostate Cancer?

In the early stages of prostate cancer, symptoms can be minor or you may have no symptoms at all. That’s why it is important for men to get screened for prostate cancers. The prostate is below the bladder and surrounds the urethra, so some of the more common symptoms of prostate cancer are issues with urination. These include:
  • Weak or interrupted flow of urine
  • Frequent and sudden urge to urinate, especially at night
  • Difficulty starting urination
  • Trouble emptying the bladder completely
  • Painful or burning sensations while urinating
  • Blood in urine or semen

Prostate cancer may also cause more generalized symptoms, such as:

  • Pain in the lower back or pelvic area
  • Weakness or numbness in the legs or feet
  • Dizziness
  • Fatigue