# Bladder Preservation with Concurrent Chemoradiotherapy Following Complete Response to Induction Systemic Therapy in Patients with Muscle-Invasive Bladder Cancer: A Review of the Existing Literature

## TL;DR

Some bladder cancer patients who respond well to initial treatment may avoid surgery by using chemotherapy and radiotherapy, preserving bladder function without compromising survival.

## Contribution

This review evaluates the feasibility and outcomes of bladder-preserving chemoradiotherapy in muscle-invasive bladder cancer patients achieving complete response to initial therapy.

## Key findings

- Bladder-preserving chemoradiotherapy enabled 50–97% of responders to retain their bladder after complete response to initial therapy.
- Long-term survival rates for these patients were favorable, with 3- to 5-year overall survival ranging from 65% to 89%.
- Treatment-related toxicity was generally acceptable, with severe late toxicity being uncommon.

## Abstract

Muscle-invasive bladder cancer (MIBC) mandates aggressive treatment with neoadjuvant systemic therapy followed by radical cystectomy for surgical candidates. However, a noteworthy subset of patients responds very well to initial therapy, and for these patients, it may be possible to treat MIBC with a combination of chemotherapy and radiotherapy, omitting cystectomy. Studies show this approach is generally safe, effective, and can preserve bladder function in selected patients. Improved induction treatments, advanced imaging techniques, and blood or urine biomarkers are awaited to better identify patients who can avoid cystectomy, without compromising oncological outcomes.

Background/Objectives: The standard surgical treatment of muscle-invasive bladder cancer (MIBC) comprises neoadjuvant systemic therapy followed by radical cystectomy (RC). However, a notable number of patients achieve a favorable response to neoadjuvant systemic therapy, a finding associated with improved outcomes, and questioning the necessity of RC in this subset of patients. The objective of this review is to summarize the available evidence regarding the feasibility, efficacy and toxicity of bladder-preserving chemoradiotherapy (CRT) following clinical response (CR) to neoadjuvant systemic therapy in patients with MIBC. Methods: A literature search was performed using the PubMed database to identify studies evaluating the use of CRT for bladder preservation in MIBC patients with CR following neoadjuvant therapy. Results: Clinical complete response (cCR) rates to neoadjuvant systemic treatment ranged from 31% to 87.5%, with subsequent CRT enabling 50–97% of responders to retain their bladder. Long-term outcomes were favorable for cCR patients, with 3- to 5-year overall survival (OS) ranging from 65% to 89%, disease-free survival (DFS) of 64–86%, and bladder-intact survival up to 80%. Achievement of cCR, T2 tumor stage, absence of concomitant carcinoma in situ or hydronephrosis, and complete transurethral resection of the bladder tumor (TURBT) were prognostic factors for improved oncologic outcomes. Treatment-related toxicity was generally acceptable, concerning mainly hematological and gastrointestinal events, while severe late toxicity was uncommon. Conclusions: Bladder-preserving CRT is a promising, effective, and well-tolerated option for MIBC patients achieving CR to neoadjuvant systemic therapy. While further prospective validation and longer follow-up are required before it can universally replace radical cystectomy in this subset of patients, advances in neoadjuvant treatments, imaging and molecular biomarkers may improve response assessment and patient selection for bladder preservation.