Late pelvic toxicity after bladder-sparing therapy in patients with invasive bladder cancer: RTOG 89-03, 95-06, 97-06, 99-06.
In selected patients with muscle-invasive bladder cancer, combined-modality therapy (transurethral resection bladder tumor [TURBT], radiation therapy, chemotherapy) with salvage cystectomy, if necessary, can achieve survival rates similar to radical cystectomy. We investigated late pelvic toxicity after chemoradiotherapy for patients treated on prospective protocols. Between 1990 and 2002, 285 eligible patients enrolled on four prospective protocols (Radiation Therapy Oncology Group [RTOG] 8903, 9506, 9706, 9906) and 157 underwent combined-modality therapy, surviving >or= 2 years from start of treatment with their bladder intact. Rates of late genitourinary (GU) and GI toxicity were assessed using the RTOG Late Radiation Morbidity Schema, with worst toxicity grade (scale 0 to 5) occurring >or= 180 days after start of consolidation therapy reported for each patient. Persistence of toxicity was defined as grade 3+ toxicity not decreasing by at least one grade. Logistic and Cox regression analyses were performed to evaluate relationship between clinical characteristics, frequency, and time to late grade 3+ pelvic toxicity. Covariates included age, sex, stage, presence of carcinoma in situ, completeness of TURBT, and protocol. Median follow-up was 5.4 years (range, 2.0 to 13.2 years). Seven percent of patients experienced late grade 3+ pelvic toxicity: 5.7% GU and 1.9% GI. In only one of nine patients did a grade 3+ GU toxicity persist. Notably there were no late grade 4 toxicities and no treatment-related deaths. None of the clinical variables studied predicted for late grade 3+ pelvic toxicity. Rates of significant late pelvic toxicity for patients completing combined-modality therapy for invasive bladder cancer and retaining their native bladder are low.