What is the PSA test?
The PSA test, short for prostate-specific antigen test, is a screening tool used to measure the level of PSA protein in the blood. This protein is produced by both healthy and cancerous cells within the prostate gland. Typically, a blood sample is collected and sent to a laboratory for analysis, with results reported as nanograms of PSA per milliliter (ng/mL) of blood.
Initially, the FDA approved the PSA test in 1986 for monitoring the progression of prostate cancer in men already diagnosed with the disease. Subsequently, in 1994, it gained approval for use alongside a digital rectal exam (DRE) to aid in the detection of prostate cancer in men aged 50 and older. Until around 2008, annual PSA screening, starting at age 50, was commonly recommended by many medical professionals and organizations.
PSA testing, often combined with a DRE, is also employed by healthcare providers when individuals report prostate-related symptoms, assisting in determining the underlying cause of these issues.
While elevated PSA levels are commonly associated with prostate cancer, they can also result from non-cancerous conditions such as prostatitis (prostate inflammation) and benign prostatic hyperplasia (BPH), which involves prostate enlargement. It's important to note that having these benign conditions does not necessarily indicate prostate cancer, although individuals may have one or both conditions and still develop prostate cancer.
Around 2008, as understanding grew regarding the advantages and drawbacks of prostate cancer screening, several medical organizations began advising against routine population screening using the PSA test. Instead, most organizations suggest that individuals considering PSA screening first consult with their healthcare providers to weigh the risks and benefits.
Is the PSA test recommended for prostate cancer screening?
However, some organizations do propose PSA screening for men at higher risk of prostate cancer, such as Black men, those with certain genetic variants, and those with a family history of the disease, starting as early as age 40 or 45.
In 2018, the United States Preventive Services Task Force (USPSTF) revised its recommendation statement for prostate cancer screening, upgrading it from a "D" (not recommended) to a "C" (selectively offering PSA-based screening based on professional judgment and patient preferences) for men aged 55 to 69. They continue to advise against PSA screening for men over 70.
The updated recommendation suggests that individuals aged 55 to 69 should decide whether to undergo periodic PSA-based screening after discussing the potential benefits and risks with their healthcare provider. This decision should align with their personal values and preferences.
Currently, Medicare covers an annual PSA test for all eligible individuals aged 50 and older, and many private insurers also cover PSA screening.
What is a normal PSA test result?
A normal PSA test result typically indicates a low level of prostate-specific antigen (PSA) in the blood. This level is commonly considered to be 4 nanograms per milliliter (ng/mL) or lower. However, the interpretation of PSA levels can vary depending on factors such as age, race, and overall health. Therefore, it is important for individuals to discuss their PSA test results with their healthcare provider to determine whether any further evaluation or monitoring is necessary.
What steps are taken if a screening test reveals a higher-than-normal PSA level?
If an individual without symptoms of prostate cancer opts for screening and shows an elevated PSA level, the physician may suggest repeating the PSA test to confirm the initial result. Should the PSA level remain high, the doctor might advise continued monitoring with regular PSA tests and digital rectal exams (DREs) to track any changes over time, a practice known as observation or watchful waiting.
In cases where the PSA level continues to rise or suspicious findings emerge during a DRE, further investigations may be recommended. These may include imaging tests like magnetic resonance imaging (MRI) or high-resolution micro-ultrasound.
Alternatively, the physician may propose a prostate biopsy. This procedure involves collecting multiple samples of prostate tissue by inserting hollow needles into the prostate and withdrawing them. Biopsy needles can be guided through the rectum wall (transrectal biopsy) or the perineum (transperineal biopsy). Subsequently, a pathologist examines the collected tissue under a microscope. Although ultrasound imaging guides both biopsy techniques, ultrasound alone cannot diagnose prostate cancer. In cases of suspicious areas detected on MRI, an MRI-guided biopsy may be performed.
Historically, men with elevated PSA levels and no other symptoms were sometimes prescribed antibiotics to investigate if an infection was responsible for the PSA elevation. However, according to the American Urological Association, there is insufficient evidence to support antibiotic use for reducing PSA levels in asymptomatic men.