Prostate Specific Antigen (PSA), Total
CPT Code(s):
84153
Turnaround Time:
4 hours
Specimen Requirements
Preferred Specimen:
Serum
Minimum Volume:
1.0 mL
Transport Container:
Serum Separator Tube (SST) or Red Top Tube
Transport Temperature:
Room Temperature
Collection Instructions:
Allow blood to clot completely prior to centrifugation. Separate serum from cells within 45 minutes of collection.
Rejection Criteria:
Plasma specimen; gross hemolysis; lipemia; improper labeling
Stability Criteria
Room Temperature:
24 hours
Refrigerated:
5 days
Frozen:
30 days
Clinical Significance
The Prostate-Specific Antigen (PSA) test is a clinically significant diagnostic tool used to measure the levels of PSA in a patient's blood. It plays a crucial role in the early detection, monitoring, and management of prostate cancer.
The specific clinical significance and diagnostic use of PSA include:
1. Screening for Prostate Cancer: PSA is commonly used as a screening tool for prostate cancer. Elevated levels of PSA in the blood may indicate the presence of prostate cancer, although it is not specific to this condition. High PSA levels can also be caused by other factors such as benign prostatic hyperplasia (BPH), prostate infections, or recent prostate procedures. Further diagnostic tests, such as a prostate biopsy, are necessary to confirm a prostate cancer diagnosis.
2. Monitoring Prostate Cancer: PSA is used to monitor the progression and response to treatment of prostate cancer. Serial measurements of PSA levels over time can help determine the effectiveness of therapies, detect cancer recurrence, and guide treatment decisions. A rising PSA level may indicate disease progression or recurrence, while a declining or stable PSA level may suggest a positive response to treatment.
3. Risk Stratification: PSA levels can help stratify the risk of prostate cancer in individuals. Higher PSA levels are associated with an increased likelihood of prostate cancer. However, it is important to consider other factors such as age, family history, and previous PSA values to accurately assess the risk.
4. Active Surveillance: In some cases, men with low-risk prostate cancer may opt for active surveillance rather than immediate treatment. Periodic monitoring of PSA levels helps identify any significant changes over time, which can guide decisions regarding the need for intervention or continued surveillance.
5. Prognostic Indicator: PSA levels can serve as a prognostic indicator for prostate cancer. Higher baseline PSA levels at the time of diagnosis are associated with a greater likelihood of advanced disease, aggressive tumor behavior, and poorer outcomes.
6. Risk Assessment for Prostate Biopsy: PSA levels, along with other factors such as age and digital rectal examination findings, are used to assess the risk of prostate cancer and determine the need for a prostate biopsy. Different cutoff levels for PSA are used based on age and other individual factors to determine the threshold for recommending a biopsy.
It is important to note that PSA has limitations, including the potential for false positives and false negatives. Factors such as age, prostate size, medications, and recent activities (such as ejaculation or cycling) can influence PSA levels. Interpretation of PSA results requires consideration of individual patient characteristics, clinical history, and other diagnostic information.
Overall, PSA is a valuable tool in the early detection, monitoring, and management of prostate cancer. It helps identify individuals at risk, aids in treatment decision-making, and plays a role in assessing treatment response and disease progression. Regular PSA testing, in combination with other clinical assessments, contributes to the overall management and care of patients with prostate cancer.