a practical guide to psa screening
DESCRIPTION
A PRACTICAL GUIDE TO PSA SCREENING. Kendall Itoku, MD St. Louis Urological Surgeons. OBJECTIVES. GENERAL BACKGROUND INFORMATION AND HISTORY OF PSA SCREENING FOR PROSTATE CANCER ADDRESS THE CONTROVERSY ON PSA SCREENING: SHOULD SCREENING FOR PROSTATE CANCER BE DONE? - PowerPoint PPT PresentationTRANSCRIPT
A PRACTICAL GUIDE TO PSA SCREENING
Kendall Itoku, MDSt. Louis Urological Surgeons
OBJECTIVES GENERAL BACKGROUND
INFORMATION AND HISTORY OF PSA SCREENING FOR PROSTATE CANCER
ADDRESS THE CONTROVERSY ON PSA SCREENING: SHOULD SCREENING FOR PROSTATE CANCER BE DONE?
PRACTICAL GUIDELINES FOR THE USE OF PSA SCREENING FOR YOUR PATIENTS
PSA SCREENING SHOULD BE DONE
ANNUALLY FOR EVERY MAN OVER 40
VSPSA SCREENING IS THE WORST PUBLIC HEALTH DISASTER IN HISTORY AND SHOULD NOT BE
DONE
Prostate Specific Antigen (PSA)
Background Information PSA is a glycoprotein produced by the
epithelial cells that line the ducts of the prostate gland.
Discovered in 1970 by Dr. Richard Ablin, University of Arizona, Tucson.
Functions to help liquify semen. Disruption of normal prostate architecture
by inflammation, infection, or cancer causes more PSA to enter circulation.
DRE, ejaculation, vigorous sex does NOT significantly alter PSA. Nor does dialysis.
Prostate Cancer Background Info
Prostate cancer is the most common noncutaneous cancer in the US.
Prostate cancer is the 2nd leading cause of male cancer mortality. (28,660 deaths 2008).
Lifetime risk of prostate cancer is estimated at 1/6. (16%) Lifetime death risk 3.4%.
Prostate cancer risk is elevated in African American men.
Prostate cancer risk is elevated in men whose father or brother have prostate cancer.
Prostate Cancer Background Info
Since the 1990’s (when PSA screening came into wide usage)
Prostate cancer deaths down 4.1% per year, 1996 to 2006.
Lower stage at time of diagnosis. (1988 19.2% with locally advanced cancer. 1998 4.4% with locally advanced cancer.)
PSA Testing is Currently Used for:
Evaluation of men at risk for prostate cancer.
Aid in early detection of prostate cancer.
Pretreatment staging and risk assessment for men with prostate cancer.
Monitoring post treatment. Guide management and treatment of
men who have a recurrence of prostate cancer.
American Urological Association
Recommendations(Revised in 2009)
A baseline PSA should be done on all men starting at age 40.
All men whose life expectancy is greater than 10 years should be screened.
Prior to PSA screening, risks and benefits should be discussed.
No prescribed cutoff PSA level should trigger a biopsy.
PSA Screening Recommendations from
other Organizations American Cancer Society (ACS): Age 50 for
average risk, 40 for high risk Centers for Disease Control and Prevention
(CDC): Insufficient evidence to determine whether benefits outweigh harms
US Preventive Services Task Force (USPSTF): Not in men 75 or older, or those expected to live less than 10 years, otherwise insufficient evidence to determine benefit.
American College of Preventive Medicine (ACPM): Questionable in elderly men with other chronic illnesses and with life expectancies fewer than 10 years.
Institute for Clinical Systems Improvement (ICSI): Not enough evidence to clearly determine whether early detection and treatment saves lives.
PROS PSA Screening can help detect
prostate cancer early. Prostate cancer is easier to treat and
more likely to be cured at an early stage.
PSA testing can be done with a simple, widely available blood test.
CONS Most prostate cancers are slow
growing and never metastasize. Treatment for prostate cancer has
risks and side effects including incontinence, ED, chronic bowel dysfunction.
PSA testing can be inaccurate with high false positives and also false negatives.
PSA testing leads to invasive follow up tests.
Prostate Biopsy Will “miss” the cancer 25% of the
time. 1-4% Risk of significant bleeding or
infection.
DRE 10% of patients with prostate cancer
have a normal PSA. DRE can detect other diseases such
as rectal cancer, hemorrhoids, fissures.
Several controlled studies have indicated that DRE combined with PSA increases accuracy of screening.
However, fear of DRE may prevent a man from undergoing screening.
Prostate, Lung, Colorectal, and Ovarian Cancer
Screening Trial (PLCO) 76,693 men, randomized to get
annual psa and DRE for 6 years or “usual care”.
PSA level to trigger bx, 4.0 11.5 year follow up preliminary
results show 22% more prostate cancer in study group vs control group. But no decrease in prostate cancer related mortality (92 deaths study group vs 82 deaths control).
European Randomized Study of Screening for
Prostate Cancer (ERSPC) 182,000 men randomized to PSA
screening every 4 years or control group.
PSA level to trigger bx, 3.0 At 9 years, 20% reduction in
prostate cancer deaths in the study group. (214 vs 326)
Prostate Cancer Prevention Trial
2950 healthy men, chemoprevention trial.
Randomized to finasteride or placebo.
7 year follow up, yearly prostate bx. Prostate cancer in 6.6%, psa <0.5. Prostate cancer in 26.9%, psa 3.1 to
4.0. Showed reduction in prostate cancer
by 24% with finasteride.
Reminder: PSA levels are elevated with
prostatitis, UTI, instrumentation. Larger prostate gland will have a
higher PSA. PSA levels are lowered by 5 alpha
reductase inhibitors. (multiply by 2) PSA levels are not significantly
affected by sex or DRE.
Tools to increase accuracy of PSA screening.
Age specific normal ranges: <50-2.5, <60-3.5, <70 4.5, <80-6.5
PSA velocity: 0.75 increase per year Free/Total PSA ratio: 25% or
greater is “good” PSA density (PSA/gland volume):
<.37ng/cc is “good”. Requires TRUS.
Premises for My PSA Screening Practical
Guidelines Prostate cancer is the most common cancer in
men. (2010 estimates 217,730 new cases, 32,000 deaths)
Early stage, localized prostate cancer is “cured” over 90% of the time.
Advanced prostate cancer has significant morbidity, including bone pain and fractures, bleeding, anemia, ureteral obstruction.
PSA screening has and will continue to reduce the number of deaths from prostate cancer.
Overdetection of prostate cancer is real, but justifiable, temporary, and modified by judgment in screening.
Younger men are most likely to benefit from screening.
My Practical Guide to PSA Screening
Discussion of risks and benefits before screening. Both DRE and PSA (unless pt refuses DRE). First screening at age 40. If psa is less than 1,
every 2-4 years till age 50. Yearly screening above age 50. High risk men absolutely should be screened
early and often. (African American, Family Hx) Age specific ranges for PSA threshold utilized.
(<50-2.5, <60-3.5,<70-4.5, <80-6.5). PSA velocity- 1 point in 1 year. Discuss not screening in men over 80yo or those
with life expectancy less than 10 years. (Don’t screen if you won’t treat.)
My Guidelines for Screening after Negative
Biopsy Repeat PSA and Free PSA in 6
months. If stable, resume annual screening.
Repeat Biopsy based on PSA velocity. (If PSA rises by 1 point in 1 year.)
If Free PSA is less than 7%, strongly consider repeat biopsy, or closer f/u (q 6 months).
Atypia and PIN are difficult judgment calls. Low threshold for repeat biopsy within 6 months.
Summary No consensus Plenty of evidence that screening is
effective and justifiable Not screening is hard to defend. Need reliable indicator to identify
clinically insignificant prostate cancer.
Use common sense and good clinical judgment.