prostate cancer (screening)

G. Pourmand MD. Tehran University of Medical Sciences

May- June 2008

Point counterpoint: Prostate cancer in the elderly man:

Should we screen men after age 65 years?

Yes No

Is prostate cancer a health care problem?

Is cancer prevalence important?

Health planning

Benefits and Harms

Most are small, confined

Cancer Incidence Rates * for Men US, 1973-1999

When Does Screening Detect Cancer?

9 years before clinical presentation

What about the prognosis?

Screen- Detected Prostate Cancer

• Conventionally Presenting Localized Disease

P.W. Nicholson, BJU International

2002,90,686-693

To Screen or Not !

• Serious Public Problem.

• Asymp. Localized Phase

• Sensitivity, Specificity and Predictive Values

• The Potential for Cure

• Improved Outcomes Relation to Screen

Cost- effectiveness

Avoid detecting biologically unimportant cancers

Detect and treat tumors Progress, Produce Symptoms and Reduce Life Expectancy

American Cancer Society Modification

(Men who eligible for Pca Screening)

PSA and DRE AnnuallyShould or Offer?

American Academy of Family

Physician And US Preventive Services Task Force

Do not Recommend Routine Screening in Low- Risk Patients

National Screening 1996

Counseling Potential Harms Benefits Scientific Uncertainties

Patient- Clinician Process

( Joint Decision Making)and

(Agree on a Course of Action)

PSA and DRE from 50 years

Life expectancy of at least 10 years

Discussion

PSA < 2 mg/ml Biannually

PSA ≥ 2 mg/ml Annually

PSA (1980)

Most useful tumor marker

1- Detection 2- Monitoring • Radiation • Radical prostatectomy • Systemic therapy

PSA

Glycoprotein

• Almost Exclusivelyin Prostate Epithelial Cells

BPH

Prostatitis

Prostatic Infarction

Is PSA Ideal Tumor Marker?

PSA thershold = 4 ng/mL:

65% F. Positive rate 20% F. Negative rate

PSA: 3 ng/mL Sensitivity Positive Predictive Value

PSA Density

PSA Velocity

Age Specific Reference

May Increase Sensitivity and specificity

Age Specific PSA, Reference Range

Age, yr Reference Range, ng/ml

40-49 …………………….. 0.0-2.5

50-59 …………………….. 0.0-3.5

60-69 …………………….. 0.0-4.5

70-79 …………………….. 0.0-6.5

Use of PSA and PSA density to detect prostate cancer in men with normal DRE

PSA density(Threshold)

Sensitivity%

Specificity%

PositivePredictive Value

%

0.10 …………… 95 24 29

0.15 …………… 79 50 34

0.30 ……………. 45 85 50

0.50 ……………. 29 95 65

Correlation Between PSA and Prostate Cancer

Total PSA (ng/mL)PSA Density= Total prostate volume (mL)

PSA Velocity

PSA ≥ 0.75 ng/mL

Digital Rectal Examination

•Detect missed Pca by PSA Screening

• Able to detect asymptomatic patient

• Abnormal DRE (3.2%-10%)

• Pca (0.2%-1.7%) in original group

ACS

DRE + Occult Blood >40 yrs

The (+ve) Predictive Value 17.8%

Sensitivity of DRE: 53.2%

Specificity of DRE: 83.6%

Trans Rectal UltraSonography

Expensive

Not available for family physicians

Suffers from lack of specificity

Biopsy

1- Elevated PSA + Benign DRE

TRUS

Visible abnormal lesions

2- Abnormal DRE + TRUS Regardless of PSA

Charecteristics of Screening Tests

Test Sensitivity%

Specificity%

PositivePredictive Value

%

DRE 45-58 96-97 24-58

TRUS 71-91 89-94 15-43

PSA> 4 ng/ml

67-89 59-97 33-47

1 Andorra 83.53

2 Macau 82.35

….

47 United States 78.14

…

130 Iran 70.86

…

222 Angola 37.92

223 Swaziland 31.99

World’s Life expectancy report

Population Pyramid for USA

Population Pyramid for Iran

1384:

2722

Age-specific Incidence Rate of Prostate cancer per 100,000 Population in Iran (2005-2006)

Points

• Prostate cancer screening remains widespread, despite recommendations against routine screening by the United States Preventive Services Task Force and the ACP, and recommendations by the AAFP for counseling about the known risks and uncertain benefits of screening for prostate cancer.

• Recent evidence shows that men older than 75 years are frequently screened for prostate cancer, despite current guidelines suggesting they are unlikely to benefit from treatment as the disease develops slowly in this age group.

Counterpoints

Table shavad

• In a national surveys of physician-reported information carried out from 1999 to 2002 by Duke University Medical Center researchers:

Counterpoints (Cont.)

• They concluded that

• Urologists were more likely to initiate the tests than non-urologists.

• Excessive PSA testing has direct and indirect costs, and reflects an inefficient allocation of resources.

Counterpoints (Cont.)

• In another National Ambulatory Medical Care Surveys performed in 1995-6:

Counterpoints (Cont.)

• High incidence of Pca in Iranian elderly men

- Ethical & moral values

• Short life following the detection

considering the life expectancy • Slow growing tumor• Death due to other

complications

Shall we screen elderly?