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.