Bladder-sparing regimens typically include up-front maximal transurethral resection (TUR) followed by induction radiation and concomitant chemotherapy. Cystoscopy is later utilized to evaluate for treatment response. If a patient shows a complete response then consolidative chemoradiation would be administered, however if there is residual disease, a patient would be considered for radical cystectomy with or without adjuvant chemotherapy.
Dr. John J Coen, from 21st Century Urology presented the results of the NRG/RTOG 0712 study during the bladder cancer session at the 2018 Genitourinary Cancers Symposium. In this Phase II, multi-center trial, patients with muscle-invasive urothelial carcinoma of the bladder who elected to pursue bladder-sparing treatment were randomized to one of two treatment groups. The first group received cisplatin/5-flurouracil (5-FU) as well as twice-daily radiotherapy. The second group received low-dose gemcitabine and daily radiotherapy. 70 patients with cT2-cT4aN0 disease were randomized between the two groups from 12/2008 to 2/2014. The primary endpoint of the study was the rate of distant metastases (DM) at 3 years. Secondary endpoints included acute and late toxicities, tumor response, and 3-year bladder-intact distant metastasis free survival. The median follow-up length for the study was 5.1 (0.4 – 7.8) years.
Patients in the cisplatin/5-FU group with twice-daily radiation were noted to have a 77.8% (21/28) rate of DM-free survival at 3 years. The group who received low-dose gemcitabine and daily radiation had an 84% (21/25) DM-free survival at 3 years. Acute and long-term toxicities were felt to be acceptably low and were similar between the two groups. There were impressive complete response (CR) rates at 3 years, with 87.9% of patients in the cisplatin/5/FU twice-daily radiation group showing a CR, and 75% of patients in the low-dose gemcitabine and daily radiation group showing a CR. Finally, they found that 66.7% of patients in the cisplatin/5-FU and twice-daily radiation group had a remained disease free and retained their bladder at 3 years, while 69% of patients in the low-dose gemcitabine and daily radiation group were disease free and with their native bladder.
Dr. Coen concluded that the DM rate at 3 years was similar in both arms of the trial and were comparable to that of previously published surgical series. Both bladder-sparing regimens were well tolerated and complete response rates were high in both arms. This study lends more weight to the argument that bladder-sparing regimens are a viable option option for appropriately selected, highly motivated patients who wish to avoid radical cystectomy for muscle-invasive urothelial carcinoma of the bladder.
Presented by: John J. Coen, MD, 21st Century Urology
Written by: Brian Kadow, MD, Fox Chase Cancer Center, Philadelphia, PA at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA