Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis (233 page)

BOOK: Wallach's Interpretation of Diagnostic Tests: Pathways to Arriving at a Clinical Diagnosis
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   Laboratory Findings
   PSA testing: PSA levels normally correlate with age and prostate size, averaging 1 ng/mL for men under age 50 and 3 ng/mL for men over age 60. A value of 4.0 ng/mL is widely used as a cutoff for prostate cancer. There are two effective methods of enhancing the specificity of the PSA test—use of an age-based reference range and calculation of the free versus total PSA ratio.
   Age-based reference range: A PSA reference range based on age should be calculated for each laboratory performing PSA testing.
   PSA free versus total ratio: The risk of prostate cancer is increased if the ratio of free to total PSA is <25%.
   PSA velocity: An annual rate of change in the PSA level >2.0 ng/mL, while not an effective screening test, offers value in assessing preoperative mortality risk.
Suggested Readings
Berger AP, Cheli C, Levine R, et al. Impact of age on complexed PSA levels in men with total PSA levels of up to 20 ng/mL.
Urology.
2003;62:840–844.
Catalona WJ, Partin AW, Slawin KM, et al. Use of the percentage of free prostate-specific antigen to enhance differentiation of prostate cancer from benign prostatic disease: a prospective multicenter clinical trial.
JAMA.
1998;279:1542–1547.
Crawford ED, DeAntoni EP, Etzioni R, et al. Serum prostate-specific antigen and digital rectal examination for early detection of prostate cancer in a national community-based program. The Prostate Cancer Education Council.
Urology.
1996;47:863–869.
D’Amico A, Chen M, Roehl K, Catalona W. Preoperative PSA velocity and the risk of death from prostate cancer after radical prostatectomy.
N Engl J Med.
2004;351:125–135.
CARCINOMA OF THE RENAL PELVIS AND URETER
   Definition
   Carcinomas of the renal pelvis and ureter are primary tumors of urothelial (transitional cell) origin. Primary tumors arising in the renal pelvis include urothelial carcinomas (>90% of cases), squamous cell carcinomas (8%), and adenocarcinomas (rare).
   Who Should Be Suspected?
   Individuals with carcinoma of the renal pelvis or ureter are most likely to have hematuria (70–95% of cases) or flank pain (8–40%) stemming from obstruction of the ureter or ureteropelvic junction by a tumor mass. Other types of urinary tract symptoms (bladder irritation, constitutional symptoms) are less likely to be seen at diagnosis (<10%). Calculi or chronic infection may precede the squamous cell carcinomas.
   Laboratory Findings
   Urine cytology: Examination of urinary sediment for malignant cells is a less reliable method for diagnosis of these cases than for bladder cancers because of the poor yield of low-grade tumors and the likelihood of synchronous bladder cancer (40–50% of cases).

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