Can Prostate Cancer Be Found Early?
Updated Results From Large Studies Indicate Reduction of Prostate Cancer Deaths 14 Years After PSA Blood Test
For some types of
screening can help find cancers in an early stage when they are more easily cured.
Two Screening Tests
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 a cancer. If you have routine yearly exams and either one of these test results becomes 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 (about 1990), the prostate cancer death rate has dropped. Doctors suspect that this reduction in prostate cancer death is a result of screening, but improvements in treatment could also have had a role.
Uncertain or False Test Results
Unfortunately, there are limits to the current screening methods.
Neither the PSA test nor the DRE is 100% 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
(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.
Prostate-Specific Antigen (PSA) Test
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. Doctors are increasingly embracing an approach of "
" (previously referred to as 'watchful waiting') whereby patients diagnosed with small, slow-growing prostate cancer are monitored twice yearly and treatment is deferred unless or until the cancer shows signs of growing.
Studies have indicated that
PSA screening does lower the prostate cancer death rate, but that such screening is accompanied by over-treatment. A multinational European study reported in 2009 found a lower risk of death from prostate cancer with PSA screening by 10 years after the screening test. A study with longer follow-up from Sweden, reported in 2010, found that prostate cancer deaths were reduced by one-half by 14 years after screening; however, 12 cancers were treated for every life saved.
These findings support the recommendation that
men of 50 or more years of age who are in sufficiently good health (ie, who expect to live 10 or more additional years), should seriously consider the possibility of prostate cancer screening, and 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.
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 September 2010