What is a “PSA bounce?”

I had brachytherapy to treat my prostate cancer and my PSA had dropped to 0.3 ng/ml. But six months ago, my PSA had gone up to 0.5, and now it’s up to 0.8 ng/ml. I’m worried that the cancer is back; my doctor said it could be a “PSA bounce.” What’s that?

William C. DeWolf, M.D., Chief of the Division of Urology at Beth Israel Deaconess Medical Center, answers:

Your concern is understandable. The last thing a prostate cancer patient wants to hear after treatment is that his prostate-specific antigen (PSA) level is on the rise!

However, as your doctor points out, you may be experiencing nothing more than a temporary, benign rise in PSA, a phenomenon often called a PSA bounce, spike, or bump. It’s defined as an increase in PSA of 0.1 to 0.5 ng/ml — or a rise in PSA of 15% or greater over the prebounce level — followed by a quick drop to prebounce levels without treatment.

As many as one-third of men who choose brachytherapy, or seed therapy, to treat their prostate cancer may experience this transient rise in PSA, usually about 18 to 24 months after the seeds are implanted. In one study, approximately 12% of men who underwent treatment with external beam radiation therapy were reported to have a PSA bounce about nine months after treatment, on average.

Doctors aren’t sure what causes a PSA bounce, though several theories exist. Studies have shown an association between recent ejaculation and higher PSA levels, for example, as well as proctitis (inflammation of the rectum) and the insertion of a catheter. Age and radiation dose may play a role as well. There can also be variability among laboratories in determining PSA levels. Another theory is that a patient may be experiencing a late reaction to the radiation, such as radiation prostatitis.

The challenge for clinicians is to determine whether the rising PSA represents a bounce or cancer progression. With radiation, treatment is generally not considered a failure until a patient experiences three consecutive increases in PSA; you’ve had two. Another definition of treatment failure following radiation is an increase of 2 ng/ml over the PSA nadir, or low point, at any time. For you, that would mean a PSA of 2.3 ng/ml.

Not knowing whether your cancer is advancing can certainly be a tremendous source of anxiety. But your physician probably wants to wait to see what your PSA level is in six months, especially since it’s still relatively low. Armed with more information, he or she will be able to make a better recommendation about treatment — or reassure you that the rise in PSA was indeed nothing more than a bump in the road.

SOURCE: Satoh T, Ishiyama H, Matsumoto K, et al. Prostate-Specific Antigen “Bounce” After Permanent 125I-Implant Brachytherapy in Japanese Men: A Multi-Institutional Pooled Analysis. BJU International 2009;103:1064–68. PMID: 19040526.

Originally published September 2009;  last reviewed on March 16, 2011.