Validation of the risk stratification newly defined in the Japanese Urological Association guidelines 2019 for non‐muscle invasive bladder cancer: A multi‐institutional collaborative study

Abstract

Objectives: To validate the risk stratification newly defined in the Japanese Urological Association guidelines 2019 for non-muscle invasive bladder cancer and provide a more accurate stratification model for a heterogeneous intermediate-risk group. Methods: A total of 1610 patients, who underwent transurethral resection, diagnosed with non-muscle invasive bladder cancer in nine collaborating hospitals were retrospectively reviewed. They were classified into low-risk, intermediate-risk, high-risk, and highest-risk groups, and recurrence-free survival, progression-free survival, cancerspecific survival, and overall survival were compared among the groups. The intermediaterisk group was subdivided into two groups based on the multivariable Cox regression model of recurrence and progression risk factors, and a revised risk model was created. Results: The progression-free survival, cancer-specific survival, and overall survival were well stratified, while the recurrence-free survival of the intermediate-risk group was the shortest among the four groups (p < 0.001). The independent risk factors for recurrence and progression-free survival in the intermediate-risk group were as follows: age ≥ 70 years, sex, multiple tumors, tumor size ≥3 cm, and recurrent cases. The intermediate-risk group was subdivided into two groups: favorable intermediate-risk group and unfavorable intermediate-risk group. The revised risk model showed significant differences. Conclusion: We validated the Japanese Urological Association guidelines 2019 stratification model. The revised risk model provided a more accurate treatment selection for this disease subset.

Editorial Comment on Validation of the risk stratification newly defined in the Japanese Urological Association guidelines 2019 for non‐muscle invasive bladder cancer: A multi‐institutional collaborative study

“…Miyamoto et al. performed a multicenter retrospective analysis in NMIBC patients, and demonstrated that the JUA guidelines 2019 could stratify recurrence‐free survival (RFS), progression‐free survival (PFS), cancer specific survival (CSS) and overall survival (OS) by dividing patients into 4 risk groups 3 . This study emphasizes the usefulness of this risk stratification for decision‐making in clinical practice.…”

Differences in oncological benefits from second transurethral resection between white‐light initial surgery and photodynamic diagnosis‐guided initial surgery for primary high‐risk non‐muscle invasive bladder cancer

“…Given the substantial heterogeneity in NMIBC, the risks of recurrence, progression, and death vary among patients with varying disease risks. Of note, patients with high‐risk NMIBC are associated with a 30%–40% risk of bladder cancer recurrence and 15%–25% of cancer progression during a 5‐year follow‐up from the initial diagnosis 1,2 …”

Validation of non‐muscle‐invasive bladder cancer risk stratification updated in the 2021 European Association of Urology guidelines

“…Among newly diagnosed patients, most (70–80%) have non‐muscle‐invasive bladder cancer (NMIBC) forms of the disease, which include Ta, T1 and Tis classifications. Despite having a low lifetime risk of death, these NMIBC forms are characterized by high rates of intravesical recurrence and progression to muscle‐invasive bladder cancer 2,3 . The heterogeneous clinical and biological behaviours of NMIBC require tailored treatment recommendations, such as intravesical chemotherapy and intravesical bacillus Calmette–Guerin (BCG) treatment, as well as follow‐up regimens involving hospital visits and invasive cystoscopy examinations.…”