AMERICAN JOURNAL OF CLINICAL PATHOLOGY Editorial
Digital Rectal Examination-Associated Alterations in Serum ProstateSpecific Antigen
Prostate-specific antigen is prostate specific, not prostate cancer specific. Elevations of PSA are noted in patients with prostatitis, benign prostatic hyperplasia, urinary retention, and cancer. Prostate-specific antigen is being evaluated in prostate cancer for screening, staging, and response after therapy. The responses of prostate cancer to surgery, radiation, and hormonal therapy can be followed by serial measurements of PSA. In fact, PSA is the best method to detect cancer recurrence. Prostate-specific antigen is limited in staging for prostate cancer because of the overlap in values between those patients with metastatic cancer and those with cancer confined to the prostate gland. It is in the area of screening for prostate cancer that there is the least information and the most controversy. It is estimated that more than 30% of men older than 50 years have prostate cancer1 and 65% of these will be of low volume and "latent" (that is, they will not kill the patient). However, prostate cancer is the second leading cause of death in men and two thirds of prostatic cancers have spread beyond the prostate at the time of initial detection. There is both a need to detect prostate cancer early and also to be able to predict which cancers will be aggressive and kill the patient. Early detection has been proved to be useful in breast cancer2 but not for lung
cancer.3 Studies are needed to prove whether early detection of prostate cancer will increase survival without increasing the mortality rate from the therapy itself. Most urologists believe that early detection will increase survival because two thirds of the patients now have metastatic disease when first diagnosed and are incurable. The three methods now used for early detection of prostate cancer are digital rectal examination, serum PSA and transrectal ultrasound. Prostate-specific antigen is slightly more sensitive in detecting prostate cancer than the other two methods. Prostate-specific antigen is limited in that small volume cancers usually are not detected4 and PSA values overlap with normals, benign prostatic hyperplasia, and prostatitis. Catalona5 states that serum PSA measurements are not sufficiently sensitive to be used alone as a screening test for prostatic cancer. In his comparison group, 13 of 61 men (21%) with prostate cancer had serum PSA levels less than 4 iig/L- Cooner's studies6 found prostate cancer detected in 11% of those with serum PSA levels less than 4 iig/L, 26% of those with levels of 4.0 to 9.9 Mg/L, and 64% of those with levels of greater than 10 Mg/L. The American Urological Association recommends screening for prostatic cancer with digital rectal examinations and serum PSA. If either of these test results is abnormal, evaluation by transrectal ultrasound is justified. If a hypoechoic area is identified, transrectal ultrasoundguided biopsy is indicated. Current studies are ongoing to evaluate serum PSA levels compared to the weight of the prostate and the rate of changes of PSA over time with the assumption that prostate cancer will show a more significant increase than benign growth. Prostate-specific antigen can be used as an immunohistochemical marker to determine whether a metastatic adenocarcinoma is of prostatic origin. JAY Y. GILLENWATER, M.D.
Professor and Chairman Department of Pathology University of Virginia School of Medicine Charlottesville, Virginia
466
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
The effect of digital rectal examination on serum prostate-specific antigen (PSA) is an important consideration that needs to be addressed. The study from Tulane by Thomson and Clejan in this issue of the American Journal of Clinical Pathology (pages 528-534) is well designed and concludes that the small increases in serum PSA after digital rectal examination are of minor clinical importance. Their conclusions seem justified by the data. The important patient group are those with normal PSA who could be elevated into one of the abnormal ranges, creating a false-positive test result. There were few patients who had increases of PSA from below the top normal value of less than 4 Aig/L to more than 4 Mg/L. Patients with high PSA values before rectal examination had the greatest increases after rectal examination.
AMERICAN JOURNAL OF CLINICAL PATHOLOGY
REFERENCES 1. McNeal JE, Bostwick DG, Kindrachuk RA, et al. Patterns of progression in prostate cancer. Lancet 1986:60. 2. Feig SA. Decreased breast cancer mortality through mammographic screening: Results of clinical trials. Radiology 1988; 167:659. 3. Fontana RS, Sanderson DR, Woolner LB, et al. Lung cancer screening: The Mayo program. J Occup Med 1986;28:746.
467
4. Stamey TA, Yang N, Hay AR, et al. Prostate-specific antigen as a serum marker for adenocarcinoma of the prostate. N Engl J Med 1987;317:909. 5. Catalona WJ, Smith DS, RatlifTTL, et al. Measurement of prostatespecific antigen in serum as a screening test for prostate cancer. N Engl J Med 1991,324:1156. 6. Cooner WH, Mosley BR, Rutherford CL Jr. Prostate cancer detection in a clinical urological practice by ultrasonography, digital rectal examination and prostate specific antigen. J Urol 1990; 143:1146.
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
Vol. 97 • No. 4
Digital Rectal Examination-Associated Alterations in Serum ProstateSpecific Antigen
Prostate-specific antigen is prostate specific, not prostate cancer specific. Elevations of PSA are noted in patients with prostatitis, benign prostatic hyperplasia, urinary retention, and cancer. Prostate-specific antigen is being evaluated in prostate cancer for screening, staging, and response after therapy. The responses of prostate cancer to surgery, radiation, and hormonal therapy can be followed by serial measurements of PSA. In fact, PSA is the best method to detect cancer recurrence. Prostate-specific antigen is limited in staging for prostate cancer because of the overlap in values between those patients with metastatic cancer and those with cancer confined to the prostate gland. It is in the area of screening for prostate cancer that there is the least information and the most controversy. It is estimated that more than 30% of men older than 50 years have prostate cancer1 and 65% of these will be of low volume and "latent" (that is, they will not kill the patient). However, prostate cancer is the second leading cause of death in men and two thirds of prostatic cancers have spread beyond the prostate at the time of initial detection. There is both a need to detect prostate cancer early and also to be able to predict which cancers will be aggressive and kill the patient. Early detection has been proved to be useful in breast cancer2 but not for lung
cancer.3 Studies are needed to prove whether early detection of prostate cancer will increase survival without increasing the mortality rate from the therapy itself. Most urologists believe that early detection will increase survival because two thirds of the patients now have metastatic disease when first diagnosed and are incurable. The three methods now used for early detection of prostate cancer are digital rectal examination, serum PSA and transrectal ultrasound. Prostate-specific antigen is slightly more sensitive in detecting prostate cancer than the other two methods. Prostate-specific antigen is limited in that small volume cancers usually are not detected4 and PSA values overlap with normals, benign prostatic hyperplasia, and prostatitis. Catalona5 states that serum PSA measurements are not sufficiently sensitive to be used alone as a screening test for prostatic cancer. In his comparison group, 13 of 61 men (21%) with prostate cancer had serum PSA levels less than 4 iig/L- Cooner's studies6 found prostate cancer detected in 11% of those with serum PSA levels less than 4 iig/L, 26% of those with levels of 4.0 to 9.9 Mg/L, and 64% of those with levels of greater than 10 Mg/L. The American Urological Association recommends screening for prostatic cancer with digital rectal examinations and serum PSA. If either of these test results is abnormal, evaluation by transrectal ultrasound is justified. If a hypoechoic area is identified, transrectal ultrasoundguided biopsy is indicated. Current studies are ongoing to evaluate serum PSA levels compared to the weight of the prostate and the rate of changes of PSA over time with the assumption that prostate cancer will show a more significant increase than benign growth. Prostate-specific antigen can be used as an immunohistochemical marker to determine whether a metastatic adenocarcinoma is of prostatic origin. JAY Y. GILLENWATER, M.D.
Professor and Chairman Department of Pathology University of Virginia School of Medicine Charlottesville, Virginia
466
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
The effect of digital rectal examination on serum prostate-specific antigen (PSA) is an important consideration that needs to be addressed. The study from Tulane by Thomson and Clejan in this issue of the American Journal of Clinical Pathology (pages 528-534) is well designed and concludes that the small increases in serum PSA after digital rectal examination are of minor clinical importance. Their conclusions seem justified by the data. The important patient group are those with normal PSA who could be elevated into one of the abnormal ranges, creating a false-positive test result. There were few patients who had increases of PSA from below the top normal value of less than 4 Aig/L to more than 4 Mg/L. Patients with high PSA values before rectal examination had the greatest increases after rectal examination.
AMERICAN JOURNAL OF CLINICAL PATHOLOGY
REFERENCES 1. McNeal JE, Bostwick DG, Kindrachuk RA, et al. Patterns of progression in prostate cancer. Lancet 1986:60. 2. Feig SA. Decreased breast cancer mortality through mammographic screening: Results of clinical trials. Radiology 1988; 167:659. 3. Fontana RS, Sanderson DR, Woolner LB, et al. Lung cancer screening: The Mayo program. J Occup Med 1986;28:746.
467
4. Stamey TA, Yang N, Hay AR, et al. Prostate-specific antigen as a serum marker for adenocarcinoma of the prostate. N Engl J Med 1987;317:909. 5. Catalona WJ, Smith DS, RatlifTTL, et al. Measurement of prostatespecific antigen in serum as a screening test for prostate cancer. N Engl J Med 1991,324:1156. 6. Cooner WH, Mosley BR, Rutherford CL Jr. Prostate cancer detection in a clinical urological practice by ultrasonography, digital rectal examination and prostate specific antigen. J Urol 1990; 143:1146.
Downloaded from http://ajcp.oxfordjournals.org/ by guest on June 5, 2016
Vol. 97 • No. 4
