Approximately half of patients receiving BCG experience treatment-related adverse events, and a significant proportion discontinue therapy prematurely.2,3 Importantly, treatment discontinuation is not solely attributable to toxicity; psychological distress, treatment burden, and unmet supportive care needs also appear to influence adherence.4 However, these non-physical contributors remain sparsely addressed. Because adherence to intravesical therapy may affect recurrence and progression outcomes, understanding the factors that influence adherence is essential for developing interventions that support treatment completion and optimize patient outcomes.
In this review, we aim to identify and evaluate the varying definitions of treatment adherence used in the literature and propose a conceptual definition to promote consistent terminology and facilitate meaningful comparisons across studies. In addition, we will map factors associated with adherence to intravesical therapy to provide a comprehensive overview of the challenges faced by patients undergoing treatment. This scoping review represents an initial step towards informing future research and guiding the development of patient-centered interventions designed to reduce barriers to adherence, improve treatment completion, and enhance quality of life. However, we do not advocate for adherence at all costs. Rather, we support a holistic and patient-centered approach that considers patients’ experiences, preferences, and supportive care needs when designing strategies to improve treatment adherence.
A scoping review methodology was selected because it allows for a systematic and rigorous exploration of a broad and heterogeneous body of literature while maintaining relatively inclusive eligibility criteria. This approach is particularly appropriate for examining an evolving and inconsistently defined concept such as treatment adherence. The primary objective of a scoping review is to map the existing literature, characterize key concepts, and identify gaps in knowledge. In contrast, a traditional systematic review with narrowly defined inclusion criteria would likely exclude potentially valuable studies due to inconsistent terminology or methodological limitations, thereby limiting the ability to fully characterize barriers to adherence in this patient population.5
The review will be conducted in accordance with the Joanna Briggs Institute Manual for Evidence Synthesis to ensure methodological rigor and transparency. Consistent with scoping review methodology, we will not perform a formal quality assessment or risk-of-bias evaluation.6,7 While this may be considered a limitation, these analyses are not central to the objective of mapping the available evidence. To maximize capture of relevant studies, we employed a broad search strategy across multiple databases and supplemented the search with grey literature, including Google Scholar, clinical guidelines, and hand-searching of specific journals. However, regional databases such as the China National Knowledge Infrastructure (CNKI) and Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) were not searched, and relevant studies from these sources may therefore have been missed.
Finally, we limited the review to studies involving BCG and Mitomycin C, as these remain the most established and widely used intravesical therapies in NMIBC. In addition, both agents continue to serve as foundational treatments in major international guidelines, whereas newer intravesical therapies are rapidly evolving. Restricting the review to BCG and Mitomycin C, therefore, allowed for a more focused and clinically relevant synthesis of the literature while reducing heterogeneity across treatment modalities.
Written by: Lisbeth Roesen Leinum,1,2 Bente Thoft Jensen,3,4 Susanne Vahr Lauridsen,5,6,7
- Department of Urology, Zealand University Hospital
- Department of Regional Health Research, University of Southern Denmark
- Department of Urology, Aarhus University Hospital
- Danish Research Center for Cancer Surgery (ACROBATIC)
- Department of Gastroenterology and Urology, Copenhagen University Hospitals, Herlev- Gentofte Hospital
- Clinical Health Promotion Centre WHO-CC, Parker Institute
- Faculty of Clinical Medicine, University of Copenhagen
- Siracusano S, Silvestri T, Bassi S, et al. Health-related quality of life after BCG or MMC induction for non-muscle invasive bladder cancer. Can J Urol. 2018;25:9480–5.
- Alcorn J, Burton R, Topping A. Patterns of patient withdrawal from BCG treatment for bladder cancer: A retrospective time interval analysis. International Journal of Urological Nursing. 2019;13:63–74. doi: 10.1111/ijun.12191
- Griebsch I, Shrestha S, Lotan Y, et al. The Impact of Intravesical Instillations on Quality of Life in Patients with Non-Muscle-Invasive Bladder Cancer: A Systematic Review. Oncol Ther. 2025;13:895–918. doi: 10.1007/s40487-025-00375-x
- Alcorn J, Burton R, Topping A. Withdrawing from treatment for Bladder cancer: Patient experiences of BCG installations. International Journal of Urological Nursing. 2020;14:106–14.
- Munn Z, Peters MDJ, Stern C, et al. Systematic review or scoping review? Guidance for authors when choosing between a systematic or scoping review approach. BMC Medical Research Methodology. 2018;18:143. doi: 10.1186/s12874-018-0611-x
- Peters M, Godfrey C, McInerney P, et al. Scoping Reviews (2020). In: Aromataris E, Lockwood C, Porritt K, et al., eds. JBI Manual for Evidence Synthesis. JBI 2024.
- Tricco AC, Lillie E, Zarin W, et al. PRISMA Extension for Scoping Reviews (PRISMA-ScR): Checklist and Explanation. Ann Intern Med. 2018;169:467–73. doi: 10.7326/M18-0850