total prostate-specific antigen (PSA)

PSA is a specific marker of prostate tissue, an increase in its level is observed in any inflammatory, benign, malignant, traumatic processes and during diagnostic and therapeutic manipulations. Therefore, it is important to determine it before any manipulation on the prostate gland: an increase is observed after biopsy of the gland (the increased level persists for 2-3 weeks), transurethral ultrasound examination, prostate massage and digital rectal examination.

PSA is almost exclusively associated with prostate disease, but is not specific for prostate cancer (CP), with elevated values ​​mainly occurring in conditions such as prostatic adenoma, acute or chronic prostatitis, and prostatic infarction. Additionally, approximately 25% of CP cases are diagnosed with normal PSA values. Despite these limitations, PSA is the most widely used marker in the evaluation of prostate cancer, both for screening and diagnostics, as well as for monitoring.

CP is the second most common cancer after lung cancer in men, accounting for approximately 15% of all cancers diagnosed, with great geographic and racial variation. Although a genetic predisposition has been demonstrated, only 9% of prostate cancer cases are hereditary (a family with at least 3 affected relatives or 2 relatives who developed prostate cancer <55 years of age). The incidence of CP depends on age. Although its progression can be influenced by various exogenous/environmental factors, there are no specific preventive measures related to diet and lifestyle.

Prostate cancer PSA-based screening is one of the most controversial topics in urology and oncology.

In 2017, the European Association of Urologists (UAE) in collaboration with the European Society of Radiotherapy and Oncology (ESRO) and the International Society for Geriatric Oncology (SIOG) developed a guide that includes the following recommendations for using CP screening and PSA testing:

• PSA testing is performed after appropriate consultation with patients (benefits and risks are considered);
• The early detection strategy of CP and the time during which it is monitored are adapted to individual risk;
• Early PSA testing is based on informed decisions: men over 50 years of age; Men over the age of 45 with a family history of CP; 40-year-old men with previous PSA values> 1 ng / ml; 60-year-old men with previous PSA values> 2 ng / ml;
• The age at which PSA testing is stopped is determined by the patient's life expectancy and condition;
• PSA significance is interpreted according to age; It has a higher prognostic value in the case of CP than rectal palpation or transrectal ultrasound;
• In patients with PSA values ​​of 4 to 10 ng / ml and a negative rectal examination, free-PSA can be determined from the same serum and the total freePSA / PSA ratio calculated. Additional testing has been shown to reduce the number of unnecessary biopsies.

In patients diagnosed with CP, PSA has different meanings according to disease stages. PSA in localized forms correlates with tumor stage and degree, while in metastatic disease PSA achieves much higher values ​​compared to localized disease. Elevated PSA levels at the start of therapy are associated with a higher risk of recurrence.

PSA also plays an important role in monitoring prostate cancer at its various stages: monitoring, decision-making on therapeutic treatment, evaluation of prognosis and effectiveness of treatment (surgical, hormonal). After initial treatment of localized CP, recurrence occurs in 20-30% of cases, so routine PSA monitoring is performed at 3, 6, and 12 months; Then every 6 months; After the 3rd year PSA is determined once a year. After radiotherapy, PSA levels gradually decline to a minimum after a few months.

Free PSA does not provide relevant clinical information in the monitoring of prostate cancer, hence this The purpose of using the test is not recommended.

How to prepare for the test?

• Venous blood is needed. For 24 hours before the analysis, the patient should refrain from ejaculation.
• 48 hours after drinking alcohol.
• Blood samples should be taken in the morning, before urological maneuvers and a few weeks after the cure of inflammatory prostate disease (prostatitis). In case of CP screening, it is recommended to consult a urologist for risk assessment.