NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

US Public Health Service. Office of Disease Prevention and Health Promotion. Clinician's Handbook of Preventive Services. 2nd edition. Washington (DC): Department of Health and Human Services (US); 1999.

  • This publication is provided for historical reference only and the information may be out of date.

This publication is provided for historical reference only and the information may be out of date.

Cover of Clinician's Handbook of Preventive Services

Clinician's Handbook of Preventive Services. 2nd edition.

Show details

39Prostate-Specific Antigen

Prostate cancer is the most frequently diagnosed cancer in men in the United States, with 209,900 new cases estimated for 1997 and 41,800 deaths. Prostate cancer is the second leading cause of cancer death in men. Risk factors for prostate cancer include increasing age (80% of prostate cancers are diagnosed in men over 65), African American race, family history, and (perhaps) increased dietary fat intake. Although prostate cancer is common, its course is extremely variable. Some prostate cancers grow rapidly, metastasize, and quickly lead to death. Many other prostate cancers, however, are clinically silent and found only incidentally at autopsy. Autopsy studies indicate that approximately 30% of men over age 50 have histologic evidence of prostate cancer, yet carry only a 3% lifetime risk for death from this disease.

The principal screening tests for prostate cancer are the digital rectal examination (DRE) (chapter 30) and elevated levels of certain tumor markers (eg, prostate-specific antigen (PSA) and prostatic acid phosphatase). PSA is a glycoprotein that is specific to the prostate but not to prostate cancer. Thus, it is produced by all types of prostate tissue, whether normal, hyperplastic, or malignant. Incomplete information regarding true- and false-negative results makes accurate calculations of the sensitivity and specificity of PSA screening impossible. The positive predictive value of a positive PSA test (values greater than 4 ng/dL) are reported in the range of 20% to 30%. Many men with benign prostatic hyperplasia will have an elevated PSA level, and some men with prostate cancer will have PSA tests in the normal range. Prostatic acid phosphatase has a much lower sensitivity and positive predictive value than PSA; thus, PSA has largely replaced it in screening.

Whether to screen asymptomatic men for prostate cancer with PSA testing is controversial. Unlike the use of Pap smears and mammograms, there are no data indicating that PSA screening decreases mortality from prostate cancer. Definitive evidence is lacking that treatments such as radical prostatectomy are superior to "watchful waiting" for localized prostate cancer.

See chapter 30 for information about digital rectal examination to detect prostate cancer.

Recommendations of Major Authorities

  • American Academy of Family Physicians --
  • Clinicians should counsel men ages 50 to 65 years about the known risks and uncertain benefits of screening for prostate cancer.
  • American Cancer Society --
  • Annual PSA testing in combination with annual digital rectal exam should be offered annually beginning at age 50 to all men who have a life expectancy of at least 10 years, or earlier to men at high risk for prostate cancer.
  • American College of Physicians --
  • Rather than screening all men for prostate cancer as a matter of routine, physicians should describe the potential benefits and known harms of screening, diagnosis, and treatment; listen to the patient's concerns; and then individualize the decision to screen. The College strongly recommends that physicians help enroll eligible men in ongoing clinical studies.
  • American College of Radiology --
  • Annual PSA testing is recommended for all men aged 50 years and older. Annual PSA testing beginning at age 40 is recommended for African American men and men with a family history of prostate cancer.
  • American Urological Association --
  • Annual PSA testing in combination with annual digital rectal examination should be offered to all men aged 50 years and older with a life expectancy of ten years or more. Annual screening should be offered at age 40 to men at high risk for prostate cancer.
  • Canadian Task Force on the Periodic Health Examination --
  • Routine use of PSA testing as part of the periodic health examination is not recommended.
  • US Preventive Services Task Force --
  • Routine screening for prostate cancer with serum tumor markers (eg, PSA), digital rectal examination, or transrectal ultrasound is not recommended.

Basics of Prostate-Specific Antigen Screening

1.

Many experts recommend that men 50 years of age and over receive individualized counseling about the known risks and possible benefits of PSA testing. Patients should be informed that:

  • Prostate cancer is an important health problem.
  • The benefits of one-time or repeated screening and aggressive treatment of prostate cancer have not yet been proven. The potential benefit of PSA screening is decreased mortality from prostate cancer that is discovered early, but there are no data to show that PSA testing decreases mortality from prostate cancer.
  • DRE and PSA can both have false-positive and false-negative results.
  • The probability that further invasive evaluation will be required as a result of testing is relatively high. Aggressive therapy is necessary to realize any benefit from the discovery of a tumor. Prostate cancer treatments have serious side effects that can include impotence, incontinence, and surgical mortality ranging from 15% to 2%. Radical prostatectomy, radiation therapy, or both in combination have not been proven to be superior to watchful waiting for localized disease.
  • Early detection may save lives and may avert future cancer-related
    illness.

2.

Concerns had been raised that PSA results, like prostatic acid phosphatase levels, would be falsely elevated by the compression of the prostate occurring during a DRE. A recent study by Crawford, et al, reported that the variations in PSA levels due to digital rectal examinations had little clinical significance (Selected References).

3.

Although there is debate about the upper limits of normal for PSA testing, manufacturers recommend using 4.0 ng/mL for monoclonal PSA tests and 2.5 ng/mL for polyclonal PSA tests. Some authorities recommend varying the strategy for follow-up of a positive PSA depending on the degree of elevation. Thus, patients with levels of 10 ng/mL or more may all get a biopsy to determine if cancer is present, but those with levels greater than 4 and less than 10 ng/mL may first receive a rectal examination, a transrectal ultrasound of the prostate, or both to help determine whether a biopsy is needed.

4.

Four methods have been proposed to improve the accuracy of PSA testing. PSA density (PSA concentration divided by the gland volume as measured by transrectal ultrasound) has been proposed as a more accurate marker for cancer because malignant tissue results in a higher level of PSA per unit weight than does normal or hypertrophied prostate tissue. PSA velocity is the annual calculation of the rate of change of PSA. Age-adjusted PSA cutoffs have also been advanced to address mean PSA increases with age. Percent free PSA is the proportion of free PSA, a particular molecular form of PSA, to the total PSA. Prostate cancer has been associated with a lower percent free PSA. These references are reviewed in Vashi (Selected References). Most authorities recommending the test advocate combining it with other modalities, such as digital rectal examination or transrectal ultrasound, to increase the positive predictive value.

Patient Resources

  • Prostate Disease: What Every Man Over 40 Should Know, and other patient materials on prostate cancer and PSA testing. Prostate Health Council. American Foundation for Urologic Disease, 1128 N. Charles Street, Baltimore, MD 21201.
  • The Prostate Puzzle. Consumer Report. 1993; 58(7):459-465.

Provider Resource

  • PDQ: The Physician Data Query System for Cancer Information. PDQ is the National Cancer Institute's computerized database providing the most up-to-date cancer information available. Access to the system can be gained 24 hours a day, 7 days a week, using a personal computer and standard telephone line, or through medical libraries. Ask a medical librarian or call 1-800 4-CANCER (option 3). In Hawaii, on Oahu, call 524-1234.

Selected References

  1. American Academy of Family Physicians. Summary of Policy Recommendations for Periodic Health Examination . Kansas City, Mo: American Academy of Family Physicians; 1997.
  2. American Cancer Society. Cancer Facts and Figures-1997. Atlanta, Ga: American Cancer Society; 1997.
  3. American Cancer Society. Summary of American Cancer Society Recommendations for the Early Detection of Cancer in Asymptomatic People . Atlanta, Ga: American Cancer Society; 1992.
  4. American Cancer Society. Cancer Information Database. Atlanta, Ga: American Cancer Society; June 1997.
  5. American College of Physicians. Screening for prostate cancer. Ann Intern Med. . 1997; 126:480–484. [PubMed: 9072936]
  6. American Urological Association. Early Detection of Prostate Cancer . Baltimore, Md: American Urological Association; 1995.
  7. Benson MC, Whang IS, Olsson CA, et al. The use of prostate-specific antigen density to enhance the predictive value of intermediate levels of serum prostate-specific antigen. J Urol . 1992; 147:817–21. [PubMed: 1371555]
  8. Canadian Task Force on the Periodic Health Examination. Screening for prostate cancer. In: The Canadian Guide to Clinical Preventive Health Care. Ottawa, Canada: Minister of Supply and Services; 1994: chap 67.
  9. Carter HB, Pearson JD, Metter EJ, et al. Longitudinal evaluation of prostate-specific antigen levels in men with and without prostate disease. JAMA . 1992; 267:2215–20. [PMC free article: PMC3461837] [PubMed: 1372942]
  10. Catalona WJ, Smith DS, Ratliff TL. Measurement of prostate-specific antigen in serum as a screening test for prostate cancer. N Engl J Med . 1991; 324:1156–61. [PubMed: 1707140]
  11. Crawford ED, Schutz MJ, Clejan S. The effect of digital rectal examination on prostate-specific antigen levels. JAMA . 1992; 267:2227–2228. [PubMed: 1372943]
  12. Coley CM, Barry MJ, Fleming C and Mulley AG. Early detection of prostate cancer — part I: prior probability and effectiveness of tests. Ann Intern Med. . 1997; 126:394–406. [PubMed: 9054286]
  13. Coley CM, Barry MH, Fleming C et al. Early detection of prostate cancer — part II: estimating the risks, benefits, and costs Ann Intern Med. 1997; 126:468-479View this and related citations using.
  14. Fleming C, Wasson JH, Albertsen PC, Barry MJ, Wennberg JE. A decision analysis of alternative treatment strategies for clinically localized prostate cancer. JAMA . 1993; 269:2650–2658. [PubMed: 8487449]
  15. Kramer BS, Brown ML, Prorok PC, Potosky AL, Hohagan JK. Prostate cancer screening: what we know and what we need to know Ann Intern Med. 1993: 119:914-923View this and related citations using.
  16. Littrup PJ, Lee F, Mettlin C. Prostate cancer screening: current trends and future implications. CA . 1992; 42:198–212. [PubMed: 1377979]
  17. Lu-Yao GL, McLerran D, Wasson J, Wennberg JE. An assessment of radical prostatectomy: time trends, geographic variation, and outcomes. JAMA . 1993; 269:2633–2636. [PubMed: 8487445]
  18. Mettlin C, Jones G, Averette H, et al. Defining and updating the American Cancer Society guidelines for the cancer-related checkup: prostate and endometrial cancers. CA . 1993; 43:42–46. [PubMed: 8422604]
  19. Stuart ME, Handley MA, Thompson RS, Conger M, Timlin D. Clinical practice and new technology: prostate-specific antigen (PSA) HMO Practice . 1993; 6(4):5–11. [PubMed: 10123759]
  20. US Preventive Services Task Force. Screening for prostate cancer.In: Guide to Clinical Preventive Services. 2nd ed. Washington, DC: US Department of Health and Human Services; 1996: chap 10.
  21. Vashi AR, Oesterling JE. Percent free prostate-specific antigen: entering a new era in the detection of prostate cancer. Mayo Clinic Proceedings. . 1997; 72:337–344. [PubMed: 9121181]
  22. Wingo PA, Landis S, Ries LAG. An adjustment to the 1997 estimate for new prostate cancer cases. CA. 1997;239-242.
PubReader format: click here to try

Views

  • PubReader
  • Print View
  • Cite this Page

Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...