Salvaging adjuvant prostate radiation.
The Study: Things were crystal clear after a string of randomized trials comparing adjuvant radiation versus observation with potential salvage radiation among patients with pathologically high-risk (pT3 and/or positive-margins) prostate cancer. Except they weren’t. EORTC 22911 in 2005 and ARO 96-02 in 2009 reported improved disease-free survival (DFS) with adjuvant radiation, with long-term follow-up of SWOG 87-94 in 2009 reporting improved overall survival (OS). Great, so all these men receive adjuvant radiation now. Except they don’t. In fact, only about 10% of men who would have been eligible for these trials currently receive adjuvant treatment. This is because many urologists believe we’re doling out a whole lot of toxicity for the benefit of only a few, so why not wait until the very first sign of PSA recurrence and then pull the trigger (i.e., early salvage)? Now we have a multi-institutional retrospective study spanning 26 years directly comparing node-negative men receiving adjuvant (at undetectable PSA) versus "early" salvage (at PSA 0.1-0.5 ng/mL) radiation. Unsurprisingly, the adjuvant cohort achieved better outcomes across all measured endpoints, including OS. Why do we say unsurprisingly? Because the authors compared a group of men with undetectable PSA to a group with biologically resistant disease. And that pretty much trumps everything else for which they eloquently controlled.
Bottom Line: Sadly, the debate on post-prostatectomy adjuvant versus early salvage radiation still RAVES until results mature from ongoing prospective trials.