What is prostate cancer?

Risk factors: The older a man gets, the higher his risk of getting prostate cancer. About 60 percent of all diagnosed prostate cancer is found in men age sixty-five or older, according to the American Cancer Society's 2013 statistics. Men with a family history of prostate cancer in an immediate relative, such as a father, brother, or son, are two to three times more likely to develop the disease. The disease is also more common among African American men, with more men in this racial group dying from the disease than in any other ethnic group. It is less common in men who are Hispanic, Asian, Native American, or from the Pacific Islands.

Etiology and the disease process: Prostate cancer is typically a slow-growing, silent disease that strikes older men. In fact, there are more men with prostate cancer who are never diagnosed and who never have symptoms than there are men diagnosed with the disease. However, some men develop an aggressive illness that can be life-threatening. There is not a clear understanding as to why some men develop an aggressive form of the disease while others may never know they have it.

Incidence: As of 2013, the American Cancer Society reports that prostate cancer is the second most common form of cancer among men in the United States (the most common is skin cancer) and the second leading cause of death, behind lung cancer. The National Cancer Institute estimated that about 233,000 men in the United States were diagnosed with this disease in 2014 and more than 29,480 men died from it.

Symptoms: Often, there are no symptoms until the disease has spread beyond the prostate, a condition called metastasis. Common symptoms may include frequent urination, a sudden urge to urinate, a weak urine stream, dribbling after urinating, straining to urinate, the inability to prevent urine leakage, or the sensation that the bladder is not empty even after urinating. Blood in the urine or semen, painful ejaculation, and pain in the lower back, hips, or thighs are also common complaints. The symptoms for prostate cancer are similar to those for the noncancerous conditions benign prostatic hyperplasia (BPH), prostatitis, or a urinary tract infection. If these symptoms occur, it is important to be checked by a doctor to determine the cause.

Screening and diagnosis: There are two tests commonly used to screen for prostate cancer: the prostate-specific antigen (PSA) blood test and the digital rectal exam (DRE). PSA is a protein produced by both normal and cancerous prostate cells that is released into the blood. This test measures the levels of PSA in the blood. High levels of PSA may be indicative of prostate cancer or noncancerous conditions.

For a digital rectal exam (DRE), the physician inserts a gloved, lubricated finger into the rectum to check the prostate for any unusual characteristics, such as an increase in size, nodules, or lumps. The benefit of the DRE as a screening tool for prostate cancer is that it can reach a part of the prostate gland where most cancers generally begin.

Men who are at high risk for the disease should begin testing with both a DRE and a PSA test at age forty-five. The recommended guidelines suggest testing for all other men beginning at age fifty.

If the PSA is high or there are suspicious findings during the DRE, additional testing is recommended. These tests may include a transrectal ultrasound or a biopsy. With a transrectal ultrasound, a small probe is inserted into the rectum to take ultrasound images of the prostate. If a suspicious area is found during the exam, a biopsy is taken. A biopsy is usually done with local anesthesia in a doctor’s office. A small needle is inserted into the prostate to remove tissue samples. These samples are then examined under a microscope by a pathologist, a doctor who specializes in identifying diseases by examining tissues and cells, to determine if cancer cells are present and, if they are, how aggressive the disease may be.

When prostate cancer is diagnosed, it is given a Gleason score. The Gleason grade is a number between two and ten that reflects how closely the cancer cells resemble normal prostate tissue. In general, a low Gleason score suggests less aggressive tumors, and a higher Gleason score suggests more aggressive tumors.

The stage of the cancer refers to the extent of disease based on tumor location, size, number of tumors, and whether the cancer has spread outside the prostate gland to surrounding organs. Stages I and II refer to early-stage disease that is confined to the prostate. Stage III refers to locally advanced disease that has spread outside the prostate gland. Stage IV refers to cancer that has metastasized and possibly spread to the lymph nodes and other organs in the body.

Treatment and therapy: There are several treatment options, depending on age, overall health of the patient, and stage and grade of cancer. For men with local or locally advanced prostate cancer, treatment options generally include a radical prostatectomy, radiation therapy, hormone therapy, cryotherapy, and watchful waiting. Radical prostatectomy is surgical removal of the prostate gland and surrounding tissues. Radiation therapy is the administration of radiation energy to the prostate to destroy the cancer cells. Hormone therapy involves treatment to lower testosterone levels in the body, thereby reducing prostate cancer cell growth. Cryotherapy involves inserting a probe into the prostate to destroy cells by freezing the prostate gland. Watchful waiting, sometimes referred to as active surveillance, is monitoring the progression of the disease with regular examinations and testing. This option is usually recommended for men with other medical conditions or for those who would not tolerate surgery well.

For men with metastatic prostate cancer or men with returning cancer after surgery or radiation treatment, hormone therapy and chemotherapy are treatment options. Hormone therapy reduces prostate cancer cell growth, and chemotherapy destroys the cancer cells circulating throughout the body. Another option may be enrollment in ongoing clinical trials. Patients should discuss these options with their doctors and families to decide the best option to pursue.

Prognosis, prevention, and outcomes: Approximately 90 percent of prostate cancer is discovered in the early stages of the disease, according to the American Cancer Society in 2013. When discovered at this stage, the five-year survival rate is almost 100 percent. When the cancer has spread to surrounding tissues or organs, the survival and cure rates vary, depending on the type and extent of disease.

As with other types of cancer, there is no definitive way to prevent prostate cancer. It is believed that good overall health; a diet low in fat and high in fruits, vegetables, and whole fibers; and plenty of exercise can strengthen the immune system and potentially slow the onset of cancer.

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