Doctors aren’t sure exactly what causes prostate cancer, but they know a lot more about its origins than they once did. Most cases of prostate cancer start when the DNA in prostate gland cells changes, causing the cells to grow abnormally.

For unknown reasons, nearly half of all men age 50 or older have some small prostate gland cell irregularities called prostatic intraepithelial neoplasia (PIN). These irregularities usually don’t require treatment, and not all cases develop into prostate cancer. While doctors aren’t sure what can cause prostate cancer, they know that high-grade PINs have a 20 percent to 30 percent chance of becoming cancerous. For men with a high-grade PIN, doctors might recommend a biopsy, PSA screening and regular rectal examinations.

Prostate cancer cells tend to grow slowly. When doctors discover that a patient has prostate cancer, they might not start treating it right away. In most cases, doctors monitor the cancer’s growth, watching to make sure that it doesn’t spread to other parts of the prostate or other areas of the body.

If the cancer does begin to spread (or metastasize), doctors have several effective treatment options. Las Vegas doctors usually don’t administer chemotherapy for prostate cancer unless the cancer has entered the lymph nodes and spread to other parts of the body. Typical alternatives include hormone therapy, surgery and radiation therapy.