Prostate cancer

Age: As men get older, (after age 50) their risk of prostate cancer increases. Individuals with risk factors for developing prostate cancer, or men above 50 years of age, should be checked for prostate cancer routinely.

Race or ethnicity: Prostate cancer exhibits tremendous differences in incidence among populations worldwide. Asian men typically have a very low incidence of prostate cancer, with age-adjusted incidence rates ranging from 2-10 per 100,000 men. Higher incidence rates are generally observed in northern European countries. African American men, however, have the highest incidence of prostate cancer in the world. In the United States, African American men have a 60% higher incidence rate compared with Caucasian men.

Family history: If an immediate family member such as a father or brother has prostate cancer, the risk of developing the disease is greater than that of the average American man. From 5-10% of prostate cancer cases are believed to be due primarily to high-risk inherited genetic factors or prostate cancer susceptibility genes.

Obesity: A high-fat diet and obesity may increase the risk of prostate cancer. Researchers theorize that fat increases production of the hormone testosterone, which may promote the development of prostate cancer cells. Obese men who are diagnosed with prostate cancer have more than two-and-a-half times the risk of dying from the disease as compared to men of normal weight at the time of diagnosis. Scientists believe that obesity increases the risk of prostate cancer by increasing inflammation and steroid hormones, such as testosterone.

High levels of testosterone: Because testosterone naturally stimulates the growth of the prostate gland, men who have high levels of testosterone, such as those with hypogonadism and men who use testosterone (steroid) therapy, are more likely to develop prostate cancer than are men who have lower levels of testosterone. Long-term testosterone treatment could cause prostate gland enlargement (benign prostatic hyperplasia or BPH). Also, doctors are concerned that testosterone therapy might fuel the growth of prostate cancer that is already present.

If the cancer is identified at its earliest stages, most men will not experience any symptoms. Some men, however, will experience symptoms that might indicate the presence of prostate cancer, including a need to urinate frequently, especially at night, difficulty starting urination or holding back urine, weak or interrupted flow of urine, painful or burning urination, difficulty in having an erection, painful ejaculation, blood in urine or semen, or frequent pain or stiffness in the lower back, hips, or upper thighs. Because these symptoms can also indicate the presence of other conditions, such as urinary tract infections or bladder problems, men who experience any of these symptoms will undergo a thorough work-up to determine the underlying cause of the symptoms.

Digital rectal exam (DRE): The digital rectal exam is a procedure commonly performed during routine physical examinations. During a DRE, a doctor feels the prostate^{gland by passing a gloved finger into the patient's rectum tofind hard or lumpy areas of the gland, which may represent anabnormality.}

Prostate-specific antigen (PSA) test: Prostate specific antigen (PSA) is an enzyme that participates in breaking down proteins in seminal fluid and plays an important role in fertility. A blood sample is drawn from a vein and analyzed for PSA, a protein that is naturally produced by the prostate gland. The highest amounts of PSA are found in the seminal fluid. It is normal for the blood stream to contain a small amount of PSA. However, if a higher than normal level is found, it may be an indication of prostate infection, inflammation, enlargement or cancer. Normal levels of PSA are less than 4.0 nanograms per milliliter (ng/ml), meaning that anything above 4.0 ng/ml is abnormal. If the PSA is elevated, or if the individual has an abnormal digital rectal exam, then further tests may be needed.^{If the PSA is elevated, further tests may be needed to investigate the cause of the discrepancy. However, these findings do not necessarily mean that a patient has prostate cancer. A DRE will also be performed.}

Using the PSA test to screen men for prostate cancer is controversial because it is not yet known if this test actually saves lives. Moreover, it is not clear if the benefits of PSA screening outweigh the risks of follow-up diagnostic tests and cancer treatments. For example, the PSA test may detect small cancers that would never become life threatening. This situation, called overdiagnosis, puts men at risk for complications from unnecessary treatment such as surgery or radiation.

Prostate biopsy: If DRE and PSA test results suggest prostate cancer, a doctor may recommend a prostate biopsy. The patient will be prescribed antibiotics, usually a three day course, before the surgery. Most individuals receive local anesthesia, such as lidocaine (Xylocaine®). To do a biopsy, a doctor inserts a small, lubricated probe about the size and shape of a cigar into the rectum (called transrectal ultrasound). The probe uses sound waves that are converted to visual data in order to see a picture of the prostate gland, which is then analyzed for changes. If an abnormal area is seen on the transrectal ultrasound, the doctor will likely biopsy that area. Then a fine, hollow needle is aimed at these areas of the prostate. A spring propels the needle into the prostate gland and retrieves a very thin section of tissue. Biopsies in general take 15-45 minutes to complete, depending upon the procedure. The procedure used to diagnose prostate cancer (prostate biopsy) may cause side effects, including bleeding and infection. Fifty-five percent of men report discomfort during the biopsy. The same procedure can be performed through the perineum area (between the anus and the scrotum, called transperineal biopsy), or through the urethra (canal that the urine travels through for elimination, called transurethral biopsy).

If a doctor thinks the cancer may have spread to other parts of the body, other tests may be used. These include procedures such as a bone scan, ultrasound, computerized tomography (CT) scan, magnetic resonance imaging (MRI), and lymph node biopsies.

Grading: Once the presence of cancer is confirmed by a biopsy, the doctor determines how aggressive the cancer is and assigns it a corresponding grade. This is done by examining and comparing tissue samples of cancerous cells and healthy prostate cells. Cancer cells may vary in shape and size. Some cells may be aggressive, while others are not. More aggressive cancers generally receive more aggressive treatments. Prognosis is also poorer if the cancer is aggressive.

The Gleason score is a tumor grading procedure used to judge how aggressive a tumor might be. During the Gleason scoring process, the pathologist takes the numbers for the two most representative types of cells seen in the prostate biopsy and adds them together. Two representative cell types seen in the tumor are rated with a number from 1=normal to 5=very abnormal. Then each of the numbers are added together to give a Gleason score.

Gleason scores will range from two to ten, with two being completely normal, and ten very aggressive cancer. Generally Gleason scores of seven or above indicate a more serious prognosis with the chance that the tumors will be quite aggressive and spread quickly unless brought under control.

Staging: Two systems are commonly used for the staging of prostate cancer: the Jewett system (stages A through D) and the American Joint Committee on Cancer (AJCC) tumor, nodes, and metastasis (TNM) system. Both systems take into account the size of the tumor, whether the lymph glands (also called lymph nodes) are affected, and whether the tumor has metastasized (spread to other areas of the body). In general, prostate cancer has four basic stages:

Stage A: In stage A, the cancer is very small and completely inside the prostate gland which feels normal when a rectal examination is performed.

Stage B: Stage B cancer is still inside the prostate gland, but is larger and a lump or hard area can be felt when a rectal examination is done.

Stage C: Stage C cancer has broken through the covering of the prostate and may have grown into the seminal vesicles.

Stage D: Stage D cancer has grown into the neck of the bladder, rectum or pelvic wall, or has spread to the lymph nodes or another part of the body.

Prostate cancer can metastasize (spread to nearby areas in the body) and can be life-threatening. Metastasis can take months to years, depending on the individual. Although early-stage prostate cancer typically is not painful, once it has spread to bones, it may produce pain, which can be intense. Urinary incontinence (leakage) may occur, erectile dysfunction (impotence), or depression may also occur.