Can Prostate Cancer Be Found Early?
For some types of cancer, screening can help find cancers in an early stage when they are more easily cured. Prostate cancer can often be found early by testing the amount of prostate-specific antigen (PSA) in the blood. Another way to find prostate cancer is the digital rectal exam (DRE), in which your doctor inserts a gloved finger into the rectum to feel the prostate gland. If the results of either one of these tests are abnormal, further testing is needed to see if there is cancer present. If you have routine yearly exams and either one of these test results become abnormal, then any cancer you might have has likely been found at an early, more treatable stage.
Since the use of early detection tests for prostate cancer became fairly common (around 1990), the prostate cancer death rate has dropped. But it isn't yet clear if this drop is a direct result of screening or caused by something else, like improvements in treatment.
Unfortunately, there are limits to the current screening methods. Neither the PSA test nor the DRE is 100 percent accurate. Abnormal results of these tests don't always mean that cancer is present, and normal results don't always mean that there is no cancer. Uncertain or false test results could cause confusion and anxiety. Some men might have a prostate biopsy (which carries its own small risks, along with discomfort) when cancer is not present, while others might get a false sense of security from normal test results when cancer is actually present.
There is no question that the PSA test can help spot many prostate cancers early, but another important issue is that it can't tell how dangerous the cancer is. Finding and treating all prostate cancers early may seem like a no-brainer. But some prostate cancers grow so slowly that they would likely 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 caused any symptoms or lead to their death. But they may still be treated with either surgery or radiation, either because the doctor can't be sure how aggressive the cancer might be, or because the men are uncomfortable not having any treatment. These treatments can have side effects that seriously affect a man's quality of life. Doctors and patients are still struggling to decide who should receive treatment and who might be able to be followed without being treated right away (an approach called "watchful waiting" or "expectant management").
Studies are underway to try to determine if early detection tests for prostate cancer in large groups of men will lower the prostate cancer death rate. Early results from two large studies haven't offered clear answers.
Initial results from a study done in the United States found that annual screening with PSA and DRE detected more prostate cancers, but it 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 four years), but the researchers estimated that about 1,400 men would need to be screened (and 48 of them treated) in order to prevent one death from prostate cancer.
Because prostate cancer tends to be a slow growing cancer, the effects of screening in these studies will likely become clearer in the coming years. Both of these studies are being continued to see if longer follow-up will provide more definitive results.
At this time, these two studies do not support the view that routine screening should be recommended for all men. Rather, these early findings support the recommendation that men should make informed decisions based on available information, discussion with their doctor, and their personal perspectives on the benefits and side effects of screening and treatment.
Until more information is available, whether you have the tests is something for you and your doctor to decide. There are many factors to take into account, including your age and health. If you are young and develop prostate cancer, it will probably shorten your life if it is not caught early. If you are older or in poor health, then prostate cancer may never become a major problem because it is generally a slow-growing cancer.
Above content provided by The American Cancer Society in partnership with Beth Israel Deaconess Medical Center. For advice about your medical care, consult your doctor.
Posted October 2011