Purpose:
Multiple prospective Radiation Therapy Oncology Group (RTOG) protocols have evaluated bladder-preserving combined-modality therapy (CMT) for muscle-invasive bladder cancer (MIBC), reserving cystectomy for salvage treatment. We performed a pooled analysis of long-term outcomes in patients with MIBC enrolled across multiple studies.
Patients and methods:
Four hundred sixty-eight patients with MIBC were enrolled onto six RTOG bladder-preservation studies, including five phase II studies (RTOG 8802, 9506, 9706, 9906, and 0233) and one phase III study (RTOG 8903). Overall survival (OS) was estimated using the Kaplan-Meier method, and disease-specific survival (DSS), muscle-invasive and non-muscle-invasive local failure (LF), and distant metastasis (DM) were estimated by the cumulative incidence method.
Results:
The median age of patients was 66 years (range, 34 to 93 years), and clinical T stage was T2 in 61%, T3 in 35%, and T4a in 4% of patients. Complete response to CMT was documented in 69% of patients. With a median follow-up of 4.3 years among all patients and 7.8 years among survivors (n = 205), the 5- and 10-year OS rates were 57% and 36%, respectively, and the 5- and 10-year DSS rates were 71% and 65%, respectively. The 5- and 10-year estimates of muscle-invasive LF, non-muscle-invasive LF, and DM were 13% and 14%, 31% and 36%, and 31% and 35%, respectively.
Conclusion:
This pooled analysis of multicenter, prospective RTOG bladder-preserving CMT protocols demonstrates long-term DSS comparable to modern immediate cystectomy studies, for patients with similarly staged MIBC. Given the low incidence of late recurrences with long-term follow-up, CMT can be considered as an alternative to radical cystectomy, especially in elderly patients not well suited for surgery.
The authors presented their pooled analysis of 468 patients enrolled across multiple studies onto six RTOG bladder-preservation studies. With a median follow-up of 4.3 years among all patients and 7.8 years among survivors (n = 205), the 5- and 10-year OS rates were 57% and 36%, respectively. These results already confirmed what is already stated in current EAU muscle-invasive bladder cancer guidelines, where bladder preservation with combined-modality therapy leads to acceptable outcomes and therefore may be considered a reasonable treatment option in well-selected patients as compared to radical cystectomy. It should also be considered in all patients where surgery is contraindicated, either relatively or absolutely as the factors that determine fitness for surgery and chemoradiotherapy differ. However it should be noted that there is still a is lack of an any randomized trial comparison. Many of the patients enrolled in trial differ from those already recruited in large radical cystectomy series. Direct comparisons cannot yet be done.