PSA blood testing is highly regarded as an efficient method of monitoring disease activity in males diagnosed with prostate cancer. PSA testing, on the other hand, is problematic as a prostate cancer screening technique.
While PSA levels usually increase as men age, very high levels may indicate prostate cancer. Unless there has been a rapid spike from a considerably lower value, a PSA level of fewer than 4 nanograms per millilitre (ng/mL) is often reassuring. Many physicians consider a total PSA level greater than 10 ng/mL to be the threshold for obtaining a biopsy to rule out cancer.
What if your PSA level is between 4 and 10 ng/mL?
While a man with a PSA level in this range may still have prostate cancer, other possible reasons such as an enlarged or inflammatory prostate are equally likely. Should you have a biopsy or should you wait?
Men with somewhat to moderately high PSA levels can now undergo additional noninvasive testing before undergoing a biopsy. It is essential to speak with a urologist to determine the next appropriate measures. "Discussing these alternatives with a urologist might help men avoid an unnecessary and uncomfortable procedure with possible side effects," says Dr Marc Garnick, a urologic cancer expert affiliated with Harvard's Beth Israel Deaconess Medical Center.
Here's an overview of these tests and how they can help you and your doctor determine if you require a biopsy.
PSA Blood testing based on
PSA test variants can assist your doctor in making a more precise assessment of your prostate cancer risk.
PSA circulate in two forms in the blood: bound to other proteins or unbound (also called "free"). A standard PSA test detects both bound and unbound PSA, together referred to as total PSA. By comparison, a free PSA test only measures unbound PSA.
This test, which is frequently performed with a regular PSA test, determines free PSA as a percentage of total PSA. A lower percentage indicates a greater chance of developing cancer. When free PSA values are 15% or below, the doctors recommend biopsies. Prostate cancer is less likely to occur when the free PSA level is more than 25%.
Index of Prostate Health (PHI). The PHI calculates prostate cancer risk using total PSA, free PSA, and proPSA (a subset of free PSA). Men with high total PSA and proPSA levels — but low free PSA levels — are more likely to develop aggressive prostate cancer, according to research.
Magnetic resonance imaging
Magnetic resonance imaging (MRI) creates a high-resolution picture of your whole prostate gland using a large magnet and a radio-wave transmitter. Magnetic characteristics of cancerous tissue differ from those of normal tissue, and an MRI scan can detect these changes. This enables the size and location of tumours to be determined.
"If your MRI reveals no evidence of cancer, some doctors advise you to continue monitoring your PSA levels," Dr Garnick adds. "If the MRI reveals the presence of cancer, it can aid in determining which region of the prostate should be biopsied."
Even though your MRI scan is normal, your doctor may recommend a biopsy if the findings of other tests are unclear, such as a free PSA level of 15% to 25%.
Prostate cancer is being monitored.
Cancer experts frequently use MRI and urine biomarker measures in addition to PSA testing to evaluate men who have chosen active surveillance — that is, monitoring for changes in a low-risk prostate cancer rather than initiating treatment immediately. "Periodic testing can help determine if cancer has progressed and whether a biopsy is necessary," says Dr Marc Garnick, a urologic cancer expert at Harvard-affiliated Beth Israel Deaconess Medical Center.
Cancer-related biological residues can be found in the urine from the prostate gland. These prostate cancer biomarkers may be found and measured using two urine tests. "The tests can be performed in conjunction with an MRI to assist decide whether a biopsy is required," Dr Garnick explains.
PCA3 is a protein produced in small amounts by normal prostate cells. When prostate cells become malignant, the PCA3 gene, which produces this protein, becomes hyperactive, causing more PCA3 to be released into the urine.
DLX1 mRNA and HOXC6 (SelectMDx urine test). Elevated levels of these two urine biomarkers are linked to prostate cancer that spreads more quickly. Low levels in the urine indicate a less aggressive malignancy and contribute to the comfort of delaying a prostate biopsy.