The Study: Right on the heels of Maniac comes RTOG 0712. Let’s start with the easy part. 70 patients with muscle invasive bladder cancer who could tolerate surgery and chemo were enrolled after undergoing maximal TURBT. They were then randomized to two bladder preservation arms—which, interesting side note, weren’t designed to be compared. Keep reading. In the “FCT” arm fluorouracil and cisplatin were administered with radiation, while in the “GD” arm gemcitabine was given. Simple, right? Wrong. The radiation regimen in FCT was the good ole RTOG twice-daily regimen, which gave 1.6 Gy each morning to the pelvis and 1.5 Gy each afternoon to the bladder → tumor cone-down. The GD “Michigan” regimen gave 2 Gy once daily to the shrinking volumes of pelvis → bladder → tumor. To be fair, the RTOG may have actually been attempting a brilliant ploy to confuse the cancer into submission. A clinical response upon cystoscopy at a scheduled break after ~40 Gy was achieved in 88% of the FCT arm and 78% of the GD arm, who all went on to complete chemoradiation followed by adjuvant gem/cis. The primary endpoint of freedom from distant failure at 3 years was 78% for FCT and 84% for GD, both exceeding the prespecified 75% threshold. In the end, grade 3-4 toxicity was seen in 64% and 55% of patients, respectively, and frowns were seen in 100% of dosimetrists and therapists.
Bottom Line: You're not wrong if you continue to stick with simple daily chemoradiation for bladder preservation. | Coen, J Clin Oncol 2018