A rising PSA level after prostate cancer treatment can occur for various reasons and shouldn’t cause immediate alarm. However, PSA that continues to rise over time may lead your doctor to do more testing or recommend further treatment.
“[A rising PSA level] could also indicate the presence of metastatic disease in a lymph node or bone somewhere, which may have been hiding all along and is now growing,” says Dr. Canfield.
Rising PSA Levels After Hormone Treatment
Hormone therapy targets prostate cancer cells by lowering male hormones, called androgens, in the body. Testosterone is one type of androgen. Androgens fuel cancer growth, so reducing their levels helps slow the disease.
However, not all prostate cancer cells respond right away to hormone treatment. Some can become resistant to this treatment over months or years.
As these treatment-resistant cells continue multiplying, they may eventually cause a rise in PSA level, according to the American Cancer Society. This signals that the cancer may be progressing again despite hormone therapy. Close monitoring of the PSA level is vital for the early detection of recurrence.
Doctors may use hormone therapy either continuously or intermittently. With continuous treatment, medications aim to keep testosterone suppressed long-term. Intermittent therapy involves cycles — you receive treatment until your PSA level decreases, then pause it while continuing PSA checks.
If the level starts climbing during the break between doses, therapy will need to be restarted to regain control. In contrast, a stable, low PSA level on the off cycle would suggest that the cancer remains responsive to intermittent treatment.
Elevated PSA After Prostatectomy
Your PSA level should be very low or even undetectable within two months of having prostate removal surgery, says the American Cancer Society.
Some PSA can stay in your bloodstream for several weeks after the operation, even if the prostate tissue was all taken out. That’s why doctors usually wait six to eight weeks before rechecking your PSA levels.
A small amount of PSA may be detected after surgery, but this doesn’t always mean cancer cells are left over. Today’s PSA tests can detect tiny amounts, and these small amounts might not be something to worry about, especially if the levels don’t rise over time. It could be that some of your healthy cells are making a bit of PSA, and it’s not from cancer.
Rising PSA After Radiation
The goal of radiation is to use high-energy beams to damage the DNA of cancer cells and kill them. However, some normal prostate cells may survive the treatment. Over time, these remaining normal cells could start multiplying again, gradually increasing PSA levels.
When a rise in PSA level is observed after radiation, your doctor will need to perform additional tests to determine if there is a cancer recurrence or just normal prostate cell regeneration causing the PSA increase. While a one-time rise in PSA is not usually a concern, a gradual and continued increase indicates possible cancer recurrence.
You may also see what is called a “PSA bounce.” This is when your PSA levels rise up for the first few years and go back down. It does not affect your prognosis, according to the American Cancer Society.
PSA bounce is common when using low-dose radiotherapy, and it occurs more often in people with a lower risk of metastasis, says Canfield. People with a higher risk usually receive androgen ablation therapy or hormone therapy along with radiotherapy, which makes the PSA bounce undetectable. “The cause [of a PSA bounce] is thought to be related to inflammation and immune-related factors following radiation,” says Canfield.