Prior institutional studies have demonstrated similar cancer-specific survival outcomes in appropriately selected patients.1 However, population-based analyses have not demonstrated equally favorable outcomes,2,3 but are often significantly limited by the granularity of the data and the inappropriate patient selection.
In this study, the authors utilized the National Cancer Database to help address this once again at the population level. They identified MIBC patients treated between 2004 and 2014 who subsequently underwent either RC with or without perioperative chemotherapy or primary CMT. RC and CMT patients were propensity score weighted based on clinical and pathologic variables.
They identified 16,180 patients (RC: 14,282; CMT: 1,898) patients who met the inclusion criteria. After performing propensity score weighting, we determined that RC and CMT differed significantly with regard OS, with CMT experiencing decreased OS relative to RC [Figure below, Hazard Ratio 1.57 (CI: 1.52-1.62); p<0.0001]. The median 5- year OS was higher for RC (40.51 months) compared to CMT (20.24 months).
While they then conclude that RC was associated with 57% improved OS compared to CMT, we highlight the significant limitations of the study below.
Limitations – There are many significant limitations of this study that inhibit its message.
- NCDB – this dataset is extremely limited by the fact that overall survival is the only oncologic outcome. Cancer-specific survival is not able to be addressed.
- All institutional series demonstrating comparable outcomes have been upfront about the necessity for specific selection criteria – ie no hydronephrosis, solitary mass, completely resected, no CIS. However, this population-level analysis does not account for this selection.
- The intent of therapy is unclear. Chemoradiation has often been used as a last ditch option for patients unfit for surgery in general practice. These patients are captured inappropriately in the CMT arm in this study and all population level studies.
- Propensity Score Analysis of Radical Cystectomy Versus Bladder-Sparing Trimodal Therapy in the Setting of a Multidisciplinary Bladder Cancer Clinic. Kulkarni GS, Hermanns T, Wei Y, Bhindi B, Satkunasivam R, Athanasopoulos P, Bostrom PJ, Kuk C, Li K, Templeton AJ, Sridhar SS, van der Kwast TH, Chung P, Bristow RG, Milosevic M, Warde P, Fleshner NE, Jewett MAS, Bashir S, Zlotta AR. J Clin Oncol. 2017 Jul 10;35(20):2299-2305. doi: 10.1200/JCO.2016.69.2327. Epub 2017 Apr 14.
- Trimodal Therapy is Inferior to Radical Cystectomy for Muscle-invasive Bladder Cancer using Population-level Data: Is There Evidence in the (Lack of) Details? Kulkarni GS, Klaassen Z. Eur Urol. 2017 Oct;72(4):488-489. doi: 10.1016/j.eururo.2017.04.028. Epub 2017 May 6. No abstract available.
- Comparative Effectiveness of Trimodal Therapy Versus Radical Cystectomy for Localized Muscle-invasive Urothelial Carcinoma of the Bladder. Eur Urol. 2017 Oct;72(4):483-487. doi: 10.1016/j.eururo.2017.03.038. Epub 2017 Apr 12. Seisen T, Sun M, …, Trinh QD.
Co-Authors: Hanzhang Wang, Wasim Chowdhury, Qianqian Liu, Joel Michalek, Ahmed M. Mansour, University of Texas Health, San Antonio, Texas
Written by: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto, twitter: @tchandra_uromd at the 18th Annual Meeting of the Society of Urologic Oncology, November 20-December 1, 2017 – Washington, DC