Clinical Significance

   PSA is measured to help detect prostate cancer, and also to monitor the response to treatment in those diagnosed with prostate cancer.

Specimen

   Serum

Stability

   Frozen (preferred) : 180 days

   Refrigerated : 5 days

Reference Range

   Males:

   Females : Not applicable

Interpretation

   PSA test results should be interpreted with caution and under the guidance of a doctor. In understanding your test results, your doctor will consider a variety of factors, including your age, ethnicity, and medications you are taking. Additionally, doctors rarely make clinical decisions based on a single elevated PSA test result. Rather, doctors may look for trends in a patient’s PSA level over time and look at other diagnostic results as well.

   Cancer screening: If you receive a high PSA result from a screening, your doctor may recommend follow up tests to help diagnose the cause. Additional tests may include a urine test to check for a urinary tract infection and/or a physical exam of the prostate, called a digital rectal exam. Repeat PSA testing may be recommended to look for trends.

   Diagnosis: A high PSA result may also prompt a doctor to recommend a biopsy if they suspect cancer. However, most people who are referred for a biopsy based on a high PSA level do not have cancer. Elevated PSA levels are more often a sign of non-cancerous conditions such as a urinary tract infection, prostatitis, or benign prostatic hyperplasia (BPH). These conditions are unrelated to prostate cancer.

   Monitoring and follow-up: If you receive an elevated PSA test result during or after prostate cancer treatment, it is important to talk to your doctor about what test results mean for you. If you are currently undergoing treatment for prostate cancer, consistently elevated levels of PSA may indicate a need to reevaluate the treatment. If you have a rising PSA level after completing cancer treatment, your doctor will consider the type of treatment you received when interpreting PSA test results. In some patients, a rising PSA after completing treatment for prostate cancer indicates that the cancer has returned.

Limitation

   Serum markers are not specific for malignancy. When age is not supplied, the results cannot be flagged as high or low. Digital rectal examination generally does not increase normal prostate-specific antigen (PSA) values. However, cystoscopy, urethral instrumentation, and prostate biopsy may increase PSA levels.