Rigi10™ Malleable Penile Prosthesis
Also Known As
Total PSA, free PSA, Kallikrein-3, KLK3, Semenogelase, Seminin, Gamma-seminoprotein
Definition
Prostate-Specific Antigen (PSA) is a protein produced by cells of the prostate gland, which is part of the male reproductive system located just below the bladder. PSA’s primary function is to help liquefy semen, thereby aiding sperm motility.1 It is normal for small amounts of PSA to be present in the bloodstream. A PSA test measures the level of this protein in a blood sample. While elevated PSA levels can be an indicator of prostate cancer, they can also be caused by other non-cancerous conditions such as benign prostatic hyperplasia (BPH), an enlarged prostate, or prostatitis, an inflammation of the prostate.2 Therefore, the PSA test is a sensitive but not entirely specific marker for prostate cancer, and further diagnostic procedures are often necessary to determine the cause of an elevated PSA level.3 The test is primarily used to screen for prostate cancer, monitor patients with a history of prostate cancer, or to assess the effectiveness of treatment.4
Clinical Context
The Prostate-Specific Antigen (PSA) test is a cornerstone in urological practice, primarily for the early detection and management of prostate cancer. Clinically, PSA testing is recommended for screening in men based on age and risk factors, such as family history of prostate cancer or African American ethnicity, after a thorough discussion of the potential benefits and harms with their healthcare provider.4 Current guidelines often suggest shared decision-making for men aged 55 to 69 years regarding PSA screening.2 For men older than 70, routine screening is generally not recommended.4
Elevated PSA levels (typically >4.0 ng/mL, though age-adjusted ranges are also considered) may trigger further investigations.4 However, it’s crucial to understand that PSA is not cancer-specific; benign conditions like benign prostatic hyperplasia (BPH) and prostatitis commonly elevate PSA levels.4 Thus, an elevated PSA necessitates a comprehensive evaluation, which may include a digital rectal exam (DRE), repeat PSA tests to monitor trends, imaging studies like multiparametric MRI (mpMRI), or other biomarker tests (e.g., Prostate Health Index, 4Kscore) to better stratify risk before proceeding to a prostate biopsy.4 A prostate biopsy remains the definitive diagnostic tool to confirm cancer.4
Patient selection for PSA testing involves considering life expectancy, comorbidities, and patient preferences due to the risks of overdiagnosis and overtreatment of indolent prostate cancers.4 Overdiagnosis refers to detecting cancers that would never have caused symptoms or death, and overtreatment can lead to significant side effects like erectile dysfunction and urinary incontinence.4 Active surveillance is an increasingly common management strategy for low-risk prostate cancer, involving regular PSA monitoring, DREs, and periodic biopsies, to avoid or delay definitive treatment and its associated morbidities.4
In patients diagnosed with prostate cancer, PSA levels are critical for staging, assessing prognosis, monitoring treatment efficacy (e.g., after surgery or radiation therapy), and detecting recurrence.4 A rising PSA after treatment (biochemical recurrence) often indicates disease progression and may prompt further imaging and therapeutic interventions.4 Expected outcomes after PSA testing vary widely; for many, it leads to reassurance or management of benign conditions, while for others, it initiates a pathway for cancer diagnosis and treatment, with the goal of improving long-term survival and quality of life for those with clinically significant disease.4