Bounce with me, bounce with me.
The Study: So does the same apply after brachy boost? This large Swedish retrospective study analyzed outcomes following definitive external beam radiation with high-dose rate (HDR) brachytherapy boost for 623 men with any-risk prostate cancer. As typically defined, PSA bounces were recorded as transient rises in PSA > 0.2 ng/mL and biochemical failures as rises in PSA ⪒ 2.0 ng/mL from nadir. This means some people (9%) had bounces that were also technically failures. Any kind of bounce occurred in 26% of patients and a failure occurred in 27%. Median size of PSA bounce was 1.5 ng/mL at a median time of 15 months from treatment. What’s more, patients with a bounce had much longer median time to PSA nadir (62 months) than those without (21 months)...probably because median duration of bounce (i.e., a stagnant rise in PSA before spontaneously falling) was 24 months, meaning these “bounces” were really more like long plateaus. And the big finish: those experiencing a PSA bounce had less than half the risk of PSA failure at a median follow-up of 11 years. Which makes a lot of sense considering with bounces, by definition, what comes up must come down.
Bottom Line: Don’t be too quick to pull the trigger on salvage therapy with the first rise in PSA following external beam radiation with brachy boost, even if > 2 ng/mL, because a continual rise isn’t inevitable. | Astrom, Radiother Oncol 2018