Understanding Prostate Cancer
The prostate is a small male reproductive system gland located between the bladder and the rectum, and it produces fluid that makes up part of a man’s semen. It is possible for cancer cells to begin to grow in this gland, leading to prostate cancer.
Men with prostate cancer often don’t know they have it, because it is possible to have the condition for years without developing any symptoms. Screening tests allow doctors to check for prostate cancer in men who do not have symptoms.
The following information will help you to understand the screening process for prostate cancer and make sense of the recommendations offered by different medical groups. Your final decision regarding whether you should be screened for prostate cancer should be made with the help of your doctor.
How Common is Prostate Cancer?
Prostate cancer is very common. In fact, in the United States, prostate cancer is the most commonly diagnosed cancer outside of skin cancer. One in every five men in this country will develop prostate cancer before his death.
Prostate cancer tends to develop slowly. Most men live with prostate cancer for a long time without any problems or symptoms, and many never experience any problems at all. Men who do have symptoms often find them troublesome, and the symptoms sometimes interfere with daily life. Symptoms of prostate cancer include blood in the semen or urine, pain during ejaculation, and difficulty urinating.
Survival rates following treatment are higher when the cancer does not spread outside the prostate. When the cancer is confined to the prostate, or only in the area around the prostate, almost all men survive. When the cancer has spread throughout the body, about a third of men live for more than five years.
Who Gets Prostate Cancer?
Although it can’t be predicted who will develop prostate cancer, there are several risk factors for the disease. You are more likely to develop prostate cancer:
- If you have a family history of the disease
- If you are African-American
- As you become older
It is possible that there are other risk factors for prostate cancer, including a high-fat diet. More research is needed to understand all of the risk factors for prostate cancer.
Benign Prostatic Hyperplasia
Another disease that becomes more common as men age is benign prostatic hyperplasia (BPH). Some of the symptoms of BPH are similar to prostate cancer, but BPH is not caused by cancer. Rather, BPH is caused by the abnormal growth of benign (non-cancerous) prostate cells. The prostate gland becomes enlarged and can push against the bladder and the urethra, causing problems with urination. No studies have shown a direct link between BPH and prostate cancer, and it is important to realize that urinary problems in older men are much more likely to be caused by BPH than by prostate cancer. If you are experiencing urinary problems, talk to your doctor.
What Types of Screening Tests are Used to Detect Prostate Cancer?
There are two main types of screening tests for prostate cancer: (1) the digital rectal exam and (2) measurement of prostate-specific antigen in the blood. Often, both screening tests are used together.
- Digital rectal exam (DRE): For this test, the doctor puts on gloves, lubricates one finger, and inserts that finger into the man’s rectum. Because the prostate is located near the rectum, the doctor is able to feel the prostate through the rectum wall and check for any unusually hard or lumpy areas. If any unusual areas are found during the DRE, the doctor will recommend further testing to determine the cause.
- Prostate-specific antigen (PSA): Prostate-specific antigen is a protein made by cells in the prostate. Most of the PSA made in the prostate leaves the body in semen, but a small amount enters the bloodstream. For PSA screening, a test is taken to measure levels of PSA in the blood. An elevated level of PSA in the blood can mean that a man has prostate cancer. BPH or an infection in the prostate can also raise PSA levels. Because of this, prostate cancer can’t be diagnosed with the PSA test alone. Instead, PSA screening is used to determine if further testing is necessary.
If screening tests suggest that you might have prostate cancer, your doctor may recommend an ultrasound exam and/or biopsy. During ultrasound, sound waves are used to create pictures of the prostate. Signs of cancer are sometimes visible in these images. During a biopsy, a small amount of prostate tissue is removed. The tissue is examined for the presence of any cancerous cells.
What are the Benefits of Screening for Prostate Cancer?
Some of the issues considered by medical societies when developing prostate cancer screening recommendations are:
- Prostate cancer is common in the United States and can cause troublesome symptoms. If it spreads, prostate cancer can be fatal.
- Studies have shown that DRE and PSA tests can help detect prostate cancer.
- Finding prostate cancer at an early stage might allow men and their doctors to explore treatment options that prevent cancer spread and improve survival rates. However, more studies are needed to better understand whether screening for prostate cancer helps men remain healthy and live longer.
- Screening tests for prostate cancer are not very accurate. If a man is found to have an elevated PSA level, additional testing must be done to determine whether cancer is actually present (diagnostic testing). The need for these additional diagnostic tests can be worrisome, and there are risks involved, even though the man may not have prostate cancer at all. Needle biopsy is a common diagnostic test and carries a small risk of infection or bleeding.
- The results of screening and diagnostic tests for prostate cancer are not always correct. Screening tests and biopsies for prostate cancer can give “false negative” results. This means that the test results will be negative for cancer when, in fact, the results should be positive. So, not every man with prostate cancer will have cancer detected using available screening and diagnostic tests. It is also possible for a PSA test to give a “false positive” result. This means that the test shows that a man may have prostate cancer, when he actually does not have it. Doctors usually do not know how quickly the cancer will grow in men with prostate cancer. Many men have slow-growing prostate cancer that is unlikely to cause any symptoms or spread within their lifetimes. It is also unclear how effective treatment for prostate cancer is—more studies are needed regarding surgery, radiation, and other forms of treatment. Many men who have slow-developing prostate cancer that is found early do not need treatment at all. Especially for older men or those with additional medical problems, doctors may suggest “watchful waiting.” Watchful waiting means that the patient and his doctor monitor the cancer but do not treat it. If a man and his doctor decide to treat prostate cancer, most treatments have risks and side effects. The doctor will not know if treatment will actually cure the prostate cancer; however, if a man does have a fast-growing prostate cancer, treatment may save his life. Common treatments for prostate cancer are radical prostatectomy—surgery to remove the prostate—and radiation therapy. These treatments can cause complications including urinary incontinence (an inability to control urine flow), erectile dysfunction (an inability to have an erection needed for sexual intercourse) or strictures (narrowing of the urethra) and, in rare cases, fatality. Most doctors think that men who will probably live less than ten years after the surgery should not have a radical prostatectomy.
What Does the Medical Community Have to Say About Prostate Cancer Screening?
Several medical societies have published recommendations for prostate cancer screening. It might surprise you to know that they do not all recommend exactly the same screening practices. Although it is often true that recommendations for medical societies differ from one another, this does not mean that one society is correct and the others are wrong. In the case of prostate cancer, it is unclear whether the benefits of screening and treatment for prostate cancer outweigh the risks and costs involved. Medical societies consider the evidence available from studies and create their best recommendations.
* The American Cancer Society and the American Urological Association recommend that health care providers offer PSA and DRE testing yearly, beginning at age 50, to men who are expected to live at least 10 years. Men at high risk, such as African-Americans and men who have a first-degree relative (father, brother, or son) diagnosed with prostate cancer at an early age, should begin testing at a younger age (45 years). They recommend that men and their healthcare providers discuss the potential benefits, side effects, and questions about early prostate cancer detection and treatment so that men can make informed decisions about testing.
- The American College of Preventive Medicine (ACPM) recommends against routine-population DRE and PSA screening. ACPM recommends that men age 50 or older, who are expected to live at least 10 years, be given information about the potential benefits and risks of screening, and the limitations of current evidence. ACPM recommends that doctors help men make their own choices about screening based on personal preference.
- The American College of Physicians recommends that health care providers give men information about the benefits and risks of prostate cancer screening to help them make decisions based on personal preference.
- The U.S. Preventive Services Task Force (appointed by the federal government) recommends against routine screening for prostate cancer; this recommendation is currently under review.
While there are differences among the medical society recommendations, most agree that the decision to screen for prostate cancer is a personal choice that should be based on education, discussions between a man and his doctor, and a firm understanding of the issues. As more information about screening and treatments for prostate cancer becomes available, medical societies may change their recommendations. For instance, recent data show that the rate of death from prostate cancer is decreasing. This may mean that the use of prostate cancer screening, as well as improvements in care, are helping men with prostate cancer live longer lives.
However, more studies are needed to truly understand the role of screening in improving survival with prostate cancer. Extensive studies are currently in progress in the United States and Europe to provide more evidence.
How Do I Make a Decision About Prostate Cancer Screening?
It is important to keep in mind that medical societies consider the male population as a whole — not individual patients—when they are making recommendations for prostate cancer screening. None of the medical societies recommends against any individual man being screened for prostate cancer. You and your doctor should consider your own risk factors, medical history, and personal concerns to develop a plan for prostate cancer screening that is appropriate for you.