The waiting is the hardest part.

Top Line: "Final" results of the RADICALS-RT trial have been presented at ESMO 2019.

The Study: Let’s keep the prostate party going. RADICALS-RT is part of a series of trials designed to hopefully give us a final answer as to whether we should give adjuvant versus early salvage radiation for resected prostate cancer. In RADICALS-RT, nearly 1400 men with either pT3-4 disease, Gleason 7+, pre-op PSA 10+, or positive surgical margins and a post-op PSA of ≤0.2 were randomized to adjuvant (immediate) versus salvage (when the PSA rose >0.2) radiation. Either 2 Gy x 33 = 66 Gy or 2.625 Gy x 20 =52.5 Gy was delivered to the prostate fossa in either arm. Now let’s be clear that these are “final” results...of the secondary endpoint progression-free survival (PFS)—not the primary endpoint freedom from distant metastasis. Progression was defined as a post-radiation PSA >0.4 or any PSA >2. Obviously, this means a rising PSA that prompted salvage radiation was not considered “progression.” At five years, there was no significant improvement in PFS with upfront adjuvant treatment: 85% versus 88% with early salvage. Adjuvant radiation was associated with a significant increase in urethral strictures (5 → 8%) and incontinence at one year (3→ 5%). In other words, monitoring the post-prostatectomy PSA before proceeding with early salvage radiation allows two-thirds of men to avoid radiation and its toxicity while maintaining biochemical control. We won’t know if this translates into comparably low rates of distant progression until the final final results.

TBL: Adjuvant post-prostatectomy radiation does not appear to improve biochemical PFS over early salvage radiation in men with prostate cancer. | Parker, ESMO 2019