Long-term Outcomes among Patients Who Achieve Complete or Near-complete Responses after the Induction Phase of Bladder Preserving Combined Modality Therapy for Muscle-invasive Bladder Cancer: A Pooled Analysis of NRG Oncology/RTOG 9906 and 0233
Menée à partir des données de deux essais incluant au total 119 patients atteints d'un cancer invasif de la vessie (durée médiane de suivi : 5,9 ans), cette étude évalue, du point de vue du taux de cystectomie de sauvetage, de la survie spécifique et de la survie globale, l'intérêt d'un traitement conservateur multimodal suivi d'une chimioradiothérapie de consolidation chez les patients dont la réponse tumorale à une chimioradiothérapie d'induction est presque complète
Purpose : Bladder preserving combined-modality therapy for muscle-invasive bladder cancer (MIBC) includes transurethral resection and concurrent chemo-RT given in two phases. After the induction phase with chemo-RT to 40 Gy the tumor response is assessed by cystoscopic biopsies and urine cytology. Early salvage cystectomy is promptly offered in case of persistent disease, otherwise patients proceed to consolidation chemo-RT to 64 Gy. Two NRG Oncology RTOG bladder protocols allowed patients with near-complete response (Ta or Tis) after the induction phase to proceed to consolidation. Methods and Materials : A pooled analysis was performed on 119 eligible patients with MIBC enrolled on two NRG Oncology RTOG trials, who were classified as having a complete (T0) or near-complete (Ta or Tis) response after induction chemo-RT and completed consolidation with a total RT dose of at least 60 Gy. Bladder recurrence, salvage cystectomy rates and disease-specific survival were estimated by the cumulative incidence method and bladder-intact and overall survivals by the Kaplan-Meier method. Results : Among the 119 eligible patients, 101 (85%) achieved T0 and 18 (15%) achieved Ta or Tis after induction chemo-RT and proceeded to consolidation. After a median follow-up of 5.9 years, 36/101 (36%) T0 patients vs. 5/18 (28%) Ta or Tis patients experienced bladder recurrence (p=0.52). Thirteen patients among complete responders eventually required late salvage cystectomy for tumor recurrence, in comparison to one patient among near-complete responders (p=0.63). Disease-specific, bladder-intact and overall survivals were not significantly different between T0 and Ta/Tis cases. Conclusions : The bladder recurrence and salvage cystectomy rates of the complete and the near-complete responders were similar. Therefore it is reasonable to recommend that patients with Ta or Tis after induction chemo-RT continue with bladder-sparing therapy with consolidation chemo-RT to full dose (60 to 64 Gy).
http://www.redjournal.org/article/S0360-3016%2815%2926529-7/abstract