Prostate-Specific Antigen, or PSA, is a protein produced primarily by cells in the prostate gland. This protein is released into the bloodstream, and a simple blood test measures its level to provide insights into prostate health. While the PSA test is widely known for its role in screening for prostate cancer, elevated levels are often caused by non-cancerous conditions like benign prostatic hyperplasia (BPH). BPH, or an enlarged prostate, is a common condition where the increased volume of glandular tissue produces more PSA, leading to higher baseline levels. When BPH causes disruptive urinary symptoms, one minimally invasive treatment option is the Rezūm procedure, which uses water vapor thermal therapy to reduce the size of the enlarged prostate tissue.
The Immediate Post-Procedure PSA Spike
The Rezūm procedure works by injecting sterile water vapor into the obstructive prostate tissue in controlled, nine-second bursts. The thermal energy stored in the steam rapidly disperses through the tissue, causing immediate cell death, a process known as necrosis. This localized destruction of prostatic cells triggers a strong, expected inflammatory response as the body begins the healing process. The inflammation and the temporary damage to the tissue structure result in a transient release of a high concentration of PSA into the bloodstream.
This acute, temporary rise in PSA levels immediately following the procedure is a predictable physiological response to the treatment, not a sign of cancer progression. The spike typically peaks within the first few days or weeks, aligning with the initial post-treatment swelling phase. Patients should understand this expected fluctuation and avoid having a PSA test performed during this acute recovery window, as the result will be artificially elevated and misleading.
Establishing the New Long-Term Baseline
Once the initial inflammation and swelling begin to subside, the body’s natural healing response starts the slow reabsorption of the ablated tissue. This reduction in the overall volume of glandular prostate tissue means there are fewer cells producing PSA, which leads to a corresponding decline in the blood level. This final, lower measurement is known as the post-treatment nadir or the new long-term baseline.
The time required for this stabilization varies between individuals but generally takes around three to six months, corresponding to the period needed for the prostate to fully remodel and for the inflammation to completely resolve. Factors that can influence the magnitude of the final PSA reduction include the original size of the prostate and the amount of tissue successfully ablated during the procedure. Larger prostates or those that undergo a more extensive volume reduction will typically see a more significant drop in the long-term PSA baseline.
Post-Rezūm Monitoring and Cancer Screening
Ongoing prostate health monitoring after the Rezūm procedure requires adjusting the timing of subsequent PSA tests to account for treatment effects. Urologists typically recommend delaying the first post-procedure PSA measurement until at least three to six months have passed. This delay ensures the acute inflammatory phase has ended and the level reflects the true new baseline achieved after tissue reduction. Testing sooner would likely capture the temporary spike, leading to unnecessary concern and potential follow-up tests.
Future cancer screening utilizes this new, lower post-treatment PSA value as the reference point for comparison. A sustained and significant rise above this established post-Rezūm baseline is what would prompt further investigation for possible cancer recurrence or new disease. The American Urological Association (AUA) guidelines for post-treatment monitoring emphasize the importance of serial PSA measurements to look for trends rather than relying on a single isolated number.
If a rise does occur years later, the speed at which the PSA level increases, often expressed as the PSA doubling time, provides additional context for the physician. Regular communication and shared decision-making with a urologist are paramount, as they interpret these trends in the context of the patient’s age, overall health, and prior medical history. A single, small fluctuation may not be cause for alarm, but a consistent, upward trajectory above the new nadir warrants a comprehensive evaluation.