What Is It?
Prostate cancer is common, but not always dangerous. When cells in the prostate become cancerous (malignant), they initially form small islands of cancer that are confined to the prostate. This localized form of cancer affects about one-third of men as they grow older. In many cases, it takes years, or even decades, for this limited cancer to grow beyond the prostate gland’s tough outer capsule.
If cancer grows beyond the prostate gland, it may invade surrounding parts of the bladder and urethra, causing problems with urination. The cancer also may spread to nearby lymph nodes, or to the bones, liver or rectum. Cancers that have spread to lymph nodes or other organs generally cannot be cured, although they often can be kept under control for a number of years with medical therapy.
Although researchers still do not know the exact cause of prostate cancer, they have identified several factors that increase the risk of getting this disease:
- Older age — Microscopic islands of cancer can be seen in the prostates of about 30 percent of men at age 60, and 50 percent to 70 percent at age 80. Overall, about three out of four cases of prostate cancer are diagnosed in men over age 65.
- African-American heritage — African-American men not only have a higher risk of prostate cancer than other men, but also tend to have prostate cancer that is more advanced at the time of diagnosis. In the United States, an African-American man is twice as likely to die of prostate cancer as a white man.
- Family history — If a man’s father or brother has been diagnosed with prostate cancer, his cancer risk is two to three times higher than a man with no family history of the illness. Genetic (inherited) factors may be responsible for approximately half of the rare prostate cancers that develop in men under the age of 55.
- Lifestyle factors — Diets high in fat, especially animal fat, are associated with an increased risk of prostate cancer. Also, evidence suggests that a diet low in selenium and vitamin E may contribute to the risk.
In men in the United States, prostate cancer is the most common cancer and the second leading cause of cancer deaths. Prostate cancer strikes about one out of every 11 white men, and one out of every nine African-American men. About 180,000 new cases of prostate cancer are diagnosed each year in the United States. Because the majority of prostate cancers are small, are confined to the prostate and don’t cause symptoms, an additional 9 million American men may have prostate cancer without knowing it.
In its early stages, prostate cancer rarely causes symptoms. However, if the cancer grows to invade the urethra or bladder, it can cause the following problems:
- A less forceful urine stream
- Urinating more often than normal (frequency)
- An intense need to urinate (urgency)
- A sudden inability to pass urine (urinary retention)
- Repeated urinary-tract infections
- Blood in the urine or semen
If prostate cancer spreads to the lymph nodes, bones or other organs, it can cause bone pain, weight loss, anemia, shortness of breath and other symptoms.
If you have symptoms that suggest you might have prostate cancer, your doctor will want to evaluate you thoroughly. He or she will start by asking about your symptoms, your medical history and your family history of prostate cancer. Your doctor will want to know whether you have ever been diagnosed with any noncancerous condition of the prostate, such as prostatitis (inflammation of the prostate) or enlarged prostate (benign prostatic hypertrophy), that could mimic the symptoms of prostate cancer.
Your doctor will examine you, and will do a digital rectal exam to feel the prostate gland directly. In this exam, the doctor will insert his or her index finger into your rectum and gently feel the surface of the prostate through the rectal wall to check for lumps, hardness and enlargement. He or she also will want a urine specimen, and probably will order a prostate-specific antigen (PSA) blood test. PSA is a protein produced by the prostate and secreted into the semen. In prostate cancer and certain noncancerous prostate disorders, PSA can leak out of the prostate, causing elevated PSA levels in the blood.
If your PSA level is elevated or your digital rectal exam is abnormal, your doctor may order additional tests, such as a prostate needle biopsy. In this procedure, a needle is used to remove small pieces of tissue from the top, middle and bottom parts of the prostate on both the left and the right sides. Your doctor also may want to take tissue samples from any suspicious areas identified by the digital rectal exam or ultrasound. The tissue will be examined by a pathologist, a physician who specializes in the diagnosis of diseased tissues.
If the results of your biopsy confirm that you have prostate cancer, the pathologist also will assign a Gleason score to your tumor. The Gleason score is an indication of how abnormal the cancer cells look under a microscope compared to normal prostate cells. The score provides a rough estimate of how likely the cancer is to grow and spread rapidly. Gleason scores generally indicate the following:
- Gleason score (total) of 2 to 4: Low-grade or nonaggressive cancer
- Gleason score (total) of 5 to7: Intermediate grade
- Gleason score (total) of 8 or higher: High-grade or aggressive cancer
If you are taking any prescription or over-the-counter medication to treat an enlarged prostate, be sure to inform your doctor. Certain prostate medications, such as finasteride (Proscar), dutasteride (Avodart) or saw palmetto, can affect the results of the PSA test.
Most cases of prostate cancer are detected by screening for the disease before it causes any symptoms. Doctors detect the illness by using the prostate-specific antigen (PSA) test and the digital rectal exam). A biopsy is done if either of the screening tests is abnormal.
Depending on your biopsy results, PSA level and physical findings, your doctor may order additional tests to determine whether your cancer has spread to your lymph nodes, bones or other sites. These tests may include a Computed tomography (CT) scan, magnetic resonance imagining (MRI) scan or bone scan.
Once prostate cancer develops, it usually grows slowly over many years. While a minority of cases of prostate cancer grow and spread rapidly, almost all prostate cancer will respond to one form of treatment or another.
There is some evidence that prostate cancer is less common in men who avoid saturated fats and take in higher amounts of vitamin E and selenium. However, there is no proof that following these guidelines will reduce your risk of prostate cancer.
Prostate cancer can be treated by blocking or lowering the levels of the male hormone testosterone. One large study looked at whether the testosterone-blocking drug finasteride (Proscar) can prevent prostate cancer. While men taking this drug had a lower risk of developing prostate cancer, they also appeared more likely to be diagnosed with an aggressive form of the disease. For this reason, experts are divided as to whether finasteride should be offered to men who have a higher than average risk of prostate cancer.
Prostate cancer can be treated several ways. Together, you and your doctor should weigh many important medical and lifestyle issues before deciding on a treatment plan. Ultimately, the best treatment for you will take into account:
- The extent of your cancer
- The chances that your cancer will grow and spread rapidly
- Your age and life expectancy
- Any underlying health conditions that would increase the risks of surgery or other treatments
- Your willingness to risk side effects
If your cancer is confined to the prostate gland alone and has not penetrated the prostate capsule, you have at least three treatment options:
- Watchful waiting — In this approach, you will not be treated immediately. Instead, your doctor will monitor the status of your cancer through regular examinations and PSA tests. This strategy generally is reserved for men whose biopsy shows a low Gleason score (nonaggressive tumor). It also is a good option for elderly men who are too ill to tolerate radiation or surgery, or who have other serious medical conditions that limit their life expectancies.
- Radiation therapy — Radiation therapy can take two forms. In external-beam radiation, you receive five to seven weeks of treatments from a machine that aims radiation at your prostate. In brachytherapy, radioactive seeds or pellets are implanted directly inside your prostate using a sterile needle guided by either ultrasound or MRI. Side effects of radiation therapy can include impotence, diarrhea, rectal bleeding and incontinence. In general, more men experience side effects from external-beam radiation than from brachytherapy.
- Surgery — Your doctor may suggest that you have a radical prostatectomy, a procedure that removes your entire prostate gland, seminal vesicles and sometimes the nearby pelvic lymph nodes. Side effects from this procedure can include incontinence and impotence. Both incontinence and impotence are more common after radical prostatectomy than after radiation therapy. However, some experts believe that surgery offers the best chance of curing prostate cancer. A “nerve-sparing” surgical technique can help to preserve sexual potency in many men who undergo radical prostatectomy.
For men whose prostate cancer has grown through the prostate capsule but has not metastasized (spread) to other organs, watchful waiting or radiation therapy with or without hormonal therapy are usually recommended.
For men with metastatic prostate cancer, doctors usually prescribe androgen-deprivation (hormone) therapy. Androgens are male sex hormones, such as testosterone. This treatment involves reducing levels of testosterone and other androgens that stimulate the prostate cancer to grow. Today, doctors most commonly use drugs to either block the effects of testosterone or stop the testicles from producing it. An alternative approach is to surgically remove the testicles in a procedure called an orchiectomy. Side effects of androgen-deprivation therapy include impotence, weight gain, decreased sex drive and osteoporosis. Some men experience hot flashes, which often can be controlled by medication.
When To Call A Professional
Call your doctor immediately if you notice blood in your urine or semen, or if your urination is painful, uncomfortable or abnormal in any way.
If you are age 50 or older, speak with your doctor about the pros and cons of prostate-cancer screening. Some experts believe that screening is the best way to prevent death and disability form prostate cancer. However, other experts worry that screening may cause more harm than good. Your doctor should be able to help you decide whether regular digital rectal exams and PSA testing makes sense for you.
If you decide to get screened, your doctor probably will perform a prostate exam and check your PSA level every one to two years beginning at age 50. Screening should start at age 45 for African-American men and men who have a family history of prostate cancer. Ongoing research may help to clarify some of the controversies in prostate-cancer screening within the next decade.
The prognosis usually is excellent. About 80 percent to 90 percent of men with localized cancer are cured. Prostate cancer rarely is cured once it has spread, but many men survive for years or even decades after being diagnosed. In fact, many more men die from other causes while they have prostate cancer than die as a result of the cancer.
Diseases and Conditions Center
All ArmMed Media material is provided for information only and is neither advice nor a substitute for proper medical care. Consult a qualified healthcare professional who understands your particular history for individual concerns.