Prostate-Specific Antigen (PSA) is a protein produced by the prostate gland. A PSA test measures its level in the blood, serving as a screening tool for prostate conditions. An “abnormal” PSA test result signifies a higher-than-expected level, prompting further medical evaluation to determine the underlying cause.
What is PSA and What Do the Levels Mean?
PSA is a protein made by prostate gland cells. Small amounts normally circulate in the bloodstream. The PSA test measures this concentration, often used to detect prostate conditions, including prostate cancer.
Normal PSA levels vary. A total PSA level below 4.0 nanograms per milliliter (ng/mL) is generally considered typical. This threshold is not absolute, as factors like age, ethnicity, and prostate size influence what is considered a usual level. An elevated PSA indicates more PSA entering the bloodstream, signaling a prostate issue, but it does not definitively mean cancer.
Why PSA Levels Can Be Elevated
Both non-cancerous and cancerous factors can increase PSA levels. A common benign cause is Benign Prostatic Hyperplasia (BPH), a non-cancerous prostate enlargement common in aging men. As the prostate grows, it produces more PSA, leading to higher blood levels.
Prostatitis, an inflammation or infection of the prostate, frequently causes PSA levels to rise. This condition can result from bacterial infections or other factors, leading to swelling and irritation. Urinary tract infections (UTIs) can similarly affect PSA levels by causing inflammation.
Certain medical procedures and activities can temporarily elevate PSA. A digital rectal exam (DRE) can briefly increase PSA by stimulating the gland. Prostate biopsies or catheter insertions also cause temporary spikes. Even ejaculation can lead to a short-term increase, typically resolving within 24 to 48 hours.
Age is another factor, as PSA levels naturally increase with age, even without a specific prostate condition. While many elevated PSA readings are due to benign conditions, prostate cancer remains a potential cause. Cancerous prostate cells can produce significantly higher amounts of PSA, leading to elevated blood levels that might indicate a tumor.
What Happens After an Abnormal PSA Test?
Following an abnormal PSA test, a doctor will recommend further evaluation. A common initial step is to repeat the PSA test after a few weeks, especially if the initial reading was slightly elevated or influenced by recent ejaculation or infection. This retest helps confirm a persistent elevation.
A digital rectal exam (DRE) is often performed to assess the prostate for abnormalities in size, shape, or texture. Imaging studies, such as a multiparametric MRI (mpMRI) of the prostate, may provide detailed images. This MRI can help identify suspicious areas that might indicate a tumor, guiding subsequent diagnostic steps.
If repeat PSA remains elevated, DRE is abnormal, or MRI shows suspicious findings, a prostate biopsy is often recommended. This procedure involves taking small tissue samples from the prostate, examined under a microscope for cancer cells. Biopsies can be guided by transrectal ultrasound (TRUS) or MRI-ultrasound fusion technology, allowing precise targeting of suspicious areas. Other blood tests, such as a free PSA test (measuring unbound PSA) or PSA velocity (tracking PSA level changes), might also be considered to assess cancer likelihood.
Understanding Your Results and Ongoing Care
After follow-up tests, especially a prostate biopsy, results clarify next steps. If cancer is detected, biopsy tissue is analyzed to determine its aggressiveness, often using the Gleason score or Grade Group system. The Gleason score (6-10) reflects how abnormal cancer cells look under a microscope, while Grade Groups (1-5) provide a simplified classification based on the Gleason score.
These scores, along with factors like cancer extent and patient health, guide treatment discussions. Treatment options vary widely, from active surveillance for low-risk cancers to surgery, radiation therapy, or other interventions. The specific approach is tailored to the individual’s situation.
If biopsy does not find cancer, or if elevated PSA is attributed to benign conditions like BPH or prostatitis, ongoing monitoring is advised. This might involve regular PSA tests and DREs to track changes over time. For men diagnosed with low-risk prostate cancer, or when elevated PSA persists without a definitive diagnosis of aggressive cancer, active surveillance may be recommended. This involves close monitoring through periodic PSA tests, DREs, and sometimes repeat biopsies or MRIs, delaying or avoiding immediate treatment unless there is evidence of disease progression.