Presentation Authors: Ronald Kool*, Adnan Adnan El-Achkar, Gautier Marq, Leonardo Monteiro, Marie Vanhuyse, Armen Aprikian, Simon Tanguay, Fabio Cury, Luis Souhami, Wassim Kassouf, Montreal, Canada
Introduction: Radiation-based therapy (RT) has emerged as a suitable alternative to radical cystectomy (RC) for muscle-invasive bladder cancer (MIBC) patients. According to most guidelines a biopsy after RT is mandatory to rule out persistent or residual disease within 3 months post treatment. Our objective was to analyze the performance of biopsy to assess response post RT.
Methods: In this retrospective study, we included all patients undergoing curative-intent RT for MIBC at our institution between 2003 and 2017. Results from cross-sectional imaging, cystoscopy, urine cytology and biopsy was collected. A descriptive analysis was performed.
Results: A total of 167 patients were included after exclusion criteria. Median age was 73 years-old. Stage repartition was 146 (87%) cT2, 11 (6,5%) cT3 and 10 (6%) cT4. Neoadjuvant chemotherapy was given in 31 (18,5%) patients. RT alone was administered in 8 (5%) patients and 159 (95%) received trimodal therapy. Post treatment cystoscopy and cytology were normal in 148 (87%) patients (Flow chart). Seventy-two (43%) underwent biopsy to assess response. Of these patients, a for-cause biopsy was performed in 13 (68%) patients whereas 53 (36%) had a control biopsy in the setting of normal cystoscopy and cytology. For cause biopsy demonstrated residual MIBC in 7 (36%), NMIBC in 2 (10%), and benign histology in 10 (52%). Control biopsy demonstrated residual MIBC in 4 (7%), NMIBC in 5 (9%), and benign histology in 44 (83%).
Conclusions: Up to 7% of patients will have residual invasive disease despite normal cystoscopy and cytology. A systematic routine biopsy after RT is recommended to assess response in all patients who are surgical candidates. Larger multi-institutional studies are needed to confirm these findings.