Prostate cancer is cancer that occurs in the prostate a small walnut shaped gland in men that produces the seminal fluid that nourishes and transports sperm.
Prostate cancer is one of the most common types of cancer in men. Usually prostate cancer grows slowly and is initially confined to the prostate gland, where it may not cause serious harm. However, while some types of prostate cancer grow slowly and may need minimal or even no treatment, other types are aggressive and can spread quickly.
Prostate cancer that's detected early when it's still confined to the prostate gland has a better chance of successful treatment.

Symptoms
Burning or pain during urination
Difficulty urinating, or trouble starting and stopping while urinating
More frequent urges to urinate at night
Loss of bladder control
Decreased flow or velocity of urine stream
Blood in urine (hematuria)
Blood in semen
Difficulty getting an erection (erectile dysfunction)
Painful ejaculation

Risk factors
Factors that can increase your risk of prostate cancer include:
Age: Your risk of prostate cancer increases as you age.
Race: For reasons not yet determined, black men carry a greater risk of prostate cancer than do men of other races. In black men, prostate cancer is also more likely to be aggressive or advanced.
Family history: If men in your family have had prostate cancer, your risk may be increased. Also, if you have a family history of genes that increase the risk of breast cancer (BRCA1 or BRCA2) or a very strong family history of breast cancer, your risk of prostate cancer may be higher.
Obesity: Obese men diagnosed with prostate cancer may be more likely to have advanced disease that's more difficult to treat.