Finding Prostate Cancer Early
Screening refers to testing to find cancer in people before they have symptoms. For some types of cancer, screening can help find cancers at an early stage, when they are likely to be easier to treat.
Prostate cancer can often be found early by testing for prostate-specific antigen (PSA) levels in a man’s blood. Another way to find prostate cancer early is the digital rectal exam (DRE), in which the doctor puts a gloved, lubricated finger into the rectum to feel the prostate gland. These tests are described in more detail in What tests can detect prostate cancer early?
If the results of either one of these tests are abnormal, further testing is often done to see if a man has cancer. If prostate cancer is found as a result of screening with the PSA test or DRE, it will probably be at an earlier, more treatable stage than if no screening were done.
Questions about the benefits of prostate cancer screening
The use of early detection tests for prostate cancer became more common in the United States starting in the early 1990s, and since then the prostate cancer death rate has dropped. But it isn’t clear that this drop is a direct result of screening. It could also have other causes, like improvements in treatment.
There is no question that screening can help find many prostate cancers early, but there are still questions about whether the benefits of screening outweigh the risks for most men.
For example, neither the PSA test nor the DRE is 100% accurate. These tests can sometimes have abnormal results even when a man does not have cancer (known as a false-positive result), or normal results even when a man does have cancer (known as a false-negative result). Unclear test results can cause confusion and anxiety. False-positive results can lead some men to have a prostate biopsy (with small risks of pain, infection, and bleeding) when they don’t have cancer. And false-negative results can give some men a false sense of security even though they actually have cancer.
Another important issue is that even if screening detects prostate cancer, doctors often can’t tell if the cancer is truly dangerous. Finding and treating all prostate cancers early might seem as if it would always be a good thing, but some prostate cancers grow so slowly that they would probably never cause problems. Because of an elevated PSA level, some men may be diagnosed with a prostate cancer that they would have never even known about at all. It would never have led to their death, or even caused any symptoms.
But these men may still be treated with either surgery or radiation, either because the doctor can’t be sure how quickly the cancer might grow and spread, or because the men are uncomfortable knowing they have cancer and not getting any treatment. Treatments like surgery and radiation can have urinary, bowel, and/or sexual side effects that can seriously affect a man’s quality of life.
Men and their doctors may end up struggling over if they need treatment or if they can just be followed closely without being treated right away (an approach called watchful waiting or active surveillance). Even when men are not treated right away, they still need regular blood PSA tests and prostate biopsies to determine the need for future treatment. These tests are linked with risks of anxiety, pain, infection, and bleeding.
Doctors are studying if early detection tests will lower the risk of death from prostate cancer. The most recent results from 2 large studies were conflicting, and didn’t offer clear answers.
- Early results from a study done in the United States found that annual screening with PSA and DRE did detect more prostate cancers than in men not screened, but this screening did not lower the death rate from prostate cancer.
- A European study did find a lower risk of death from prostate cancer with PSA screening (done about once every 4 years), but the researchers estimated that about 1,050 men would need to be screened (and 37 treated) in order to prevent one death from prostate cancer.
- Neither of these studies has shown that PSA screening helps men live longer (lowers the overall death rate).
Prostate cancer is often a slow-growing cancer, so the effects of screening in these studies may become clearer in the coming years. Both of these studies are being continued to see if longer follow-up will give clearer results. Several other large studies of prostate cancer screening are now going on as well.
At this time, the American Cancer Society recommends that men thinking about getting screened for prostate cancer make informed decisions based on available information, discussion with their doctor, and their own views on the possible benefits, risks, and limits of prostate cancer screening. (See American Cancer Society recommendations for prostate cancer early detection.)
Until more information is available, you and your doctor should decide whether you should be screened for prostate cancer. There are many factors to take into account, including your age and health. If you’re young and develop prostate cancer, it may shorten your life if it’s not caught early. Screening men who are older or in poor health is less likely to help them live longer. This is because most prostate cancers are slow-growing, and men who are older or have major health problems are more likely to die from other causes before their prostate cancer grows enough to cause problems.
Last Medical Review: April 1, 2016 Last Revised: April 14, 2016
- Prostate Cancer Risk Factors
- Can Prostate Cancer Be Prevented?
- Finding Prostate Cancer Early
- What Tests Can Detect Prostate Cancer Early?
- American Cancer Society Recommendations for Prostate Cancer Early Detection
- If Prostate Cancer Screening Test Results Aren’t Normal
- Insurance Coverage for Prostate Cancer Screening
- Additional Resources: Prostate Cancer Prevention and Early Detection
- References: Prostate Cancer Prevention and Early Detection