- 21 Mar, 2021
- 0 Comments
- 3 Mins Read
How the prostate-specific antigen (PSA) diagnostic test is used in health care. What is its purpose, how is it conducted, and what information does it g
How the prostate-specific antigen (PSA) diagnostic test is used in health care. What is its purpose, how is it conducted, and what information does it gather?
The purpose of a PSA test is that it is part of the screening process to detect and monitor prostate cancer (Dains, Baumann, & Scheibel, 2016). It is conducted via blood draw from the arm and the information it gathers displays how much PSA is being secreted by the prostate gland (Prostate Cancer Foundation, n.d.). Since PSA is regular protein secreted by the prostate, PSA level of 1 to 4 ng/mL is considered normal. A PSA level of 4 to 10 ng/mL is considered high, promoting additional testing such as a digital rectal exam (DRE) or transrectal ultrasound (TRUS) with biopsy. PSA levels greater than 10 ng/mL is suspicious of malignant activity (Dains, Baumann, & Scheibel, 2016). However, not all elevated levels of PSA are cancerous in origin.
Issues with sensitivity and reliability.
An elevated PSA does not always indicate that a malignant change is happening; there are non-cancerous circumstances that can give a false-positive. A false-positive test result may manifest undo anxiety for a patient and may lead to additional medical procedures, such as a prostate biopsy. Possible side effects of prostate biopsy can include infection, pain, and bleeding (National Cancer Institute, 2017). Prostatitis is a condition triggered by bacterial infection causing the prostate to become inflamed, tender, and swollen resulting in a high PSA. Benign prostatic hyperplasia (BPH) is a larger-than-usual prostate and may have a higher than usual baseline PSA. A urinary tract infection can also irritate the prostate gland causing increased production of PSA. In addition, prostate stimulation through sexual activity or a DRE can also result in a temporarily elevated PSA (Prostate Cancer Foundation, n.d.). Conversely, there are some drugs including finasteride and dutasteride that are used to treat BPH which will lower a man’s PSA level; this can create a false-negative. False-negative test results may give the patient false assurance that he does not have cancer when in fact they could requiring treatment (National Cancer Institute, 2017).
Evidence-based literature regarding validity and reliability.
Up until 2008, physician’s and professional organizations encouraged PSA screening on an annual basis for men beginning at age 50 (National Cancer Institute, 2017). However, the specific mortality benefit of early detection is unclear. This is in part due to the inconsistency between the two large trials comparing PSA screening to usual care (Kim & Andriole, 2015). A large randomized clinical trial conducted on prostate cancer mortality showed that there was no difference in mortality rates from prostate cancer between the control group and the screening group. The screening provided no reduction in death rates at seven years and no evidence of benefit with 67% of the subjects who completed 10 years of follow-up (Dains, Baumann, & Scheibel, 2016). Conversely, a European study brought evidence about mortality outcomes from prostate cancer screenings. The study demonstrated that the risk of prostate cancer was reduced by 20% in men aged 55-69 years that underwent PSA screening (Dains, Baumann, & Scheibel, 2016).
Ethical dilemmas or controversies related to the test.
Ethical dilemmas regarding prostate cancer screening are primarily related to PSA testing. As discussed, evidence-based literature from two large studies has opposing evidence on prostate cancer mortality with PSA screening. Due to the sensitivity and specificity associated with PSA screening, using PSA as a marker for early prostate cancer detection remains controversial (Qureshi, Bennett, Hermanson, Horner, Haider, et al., 2015). The PSA test can help identify small tumors, however many tumors discovered through PSA testing grow so slowly and not likely to threaten a man’s life. Detecting and treating tumors that are not life-threatening is “overdiagnosis,” and treating these tumors is considered “overtreatment” (National Cancer Institute, 2017). Overtreatment can expose the patient unnecessary complications and harmful side effects with treatment such as surgery or radiation therapy. These side effects can cause problems with bowel function, urinary incontinence, erectile dysfunction, and infection (National Cancer Institute, 2017). Because of the risks and benefits and assessment of balance, the U.S. Preventative Services Task Force recommends against routine PSA-based screening. PSA screening should only be done if benefits outweigh risk and the patient fully understands the uncertainties (Dains, Baumann, & Scheibel, 2016).