Should everyone be screened for prostate cancer?
For American men, the lifetime risk of developing prostate cancer is 16%,
while dying from the cancer is only 2.9%. Prostate cancer survival involves
a number of factors, including the extent of the tumor at time of diagnosis,
with more localized disease having better outcomes. However in autopsy
studies, prostate cancer is found in 1/3 of men under 80 years old and
2/3 of older men, suggesting that prostate cancer grows so slowly that
most men die of other causes before the cancer is clinically significant.
So while it is clear that early detection and treatment of prostate cancer
improves treatment effectiveness, the benefits of screening men for it
are less clear. The US Preventative Service Task Force recommends against
screening, while both the American Cancer Society and American Urological
Society emphasize individualized decision making. Ultimately, it is important
for any man to discuss his personal risks and benefits of screening with
his doctor before deciding.
As such, here are some questions everyone should consider before prostate
- Who is at an increased risk for prostate cancer?
Risk factors for prostate cancer include age (rarely occurs before age
40), ethnicity (more common in African-Americans), and family history
of prostate cancer.
- What are the screening tests for prostate cancer?
1. Digital rectal exam (DRE): This exam allows the practitioner to feel the size and shape of the prostate
gland. It can detect asymmetry, changes in consistency, or nodules in
the prostate. However, only 85% of prostate cancers occur in a location
that can be detected by the DRE. For this reason, it is usually used in
conjunction with PSA (below).
2. Prostate specific antigen (PSA): PSA is a protein produced by the prostate and found in the blood. Conditions
that may elevate the PSA include prostate inflammation/infection, benign
enlargement of the prostate, and local trauma. One drawback of this test
is that it cannot reliably distinguish between cancer, benign prostate
enlargement, or inflammation.
- What happens after an abnormal screening test?
Confirmation of results by prostate biopsy is the next step. If cancer
is found, the cancer is then staged and treated. However, even if no cancer
is found, cancer may still be present because prostate biopsy is not a
perfect test. Repeat biopsies may be needed. The complications of biopsy
include pain, infection, rectal/urinary tract bleeding and urinary tract
- What is the harm of screening?
Harm primarily occurs from unnecessary prostate biopsies. Screening may
identify cancers that would never have become clinically significant.
Patients are then subjected to unnecessary biopsies and the psychological
stress of being diagnosed with cancer. Furthermore, patients with negative
biopsy results may be distressed as biopsy results cannot conclusively
rule out cancer, leading to chronic anxiety.
- What is the benefit of screening?
The goal of screening is early diagnosis and treatment so that cancers
can be put into remission or even cured, with the ultimate objective being
the prevention of deaths and decreasing mortality rates. However, of the
two major trials (ERSPC & PLCO screening trial) investigating the
effectiveness of prostate cancer screening, only the ERSPC showed a reduction
in cancer deaths with screening. Both studies found prostate cancer screening
did not affect a man’s overall mortality.
As always, if you have questions or concerns, it is best to meet with your
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