RESUMEN
Grade is an important determinant of progression in non-muscle-invasive bladder cancer. Although the World Health Organization (WHO) 2004/2016 grading system is recommended, other systems such as WHO1973 and WHO1999 are still widely used. Recently, a hybrid (three-tier) system was proposed, separating WHO2004/2016 high grade (HG) into HG/grade 2 (G2) and HG/G3 while maintaining low grade. We assessed the prognostic performance of HG/G3 and HG/G2. Three independent cohorts with 9712 primary (first diagnosis) Ta-T1 bladder tumors were analyzed. Time to progression was analyzed with cumulative incidence functions and Cox regression models. Harrell's C-index was used to assess discrimination. Time to progression was significantly shorter for HG/G3 than for HG/G2 in multivariable analyses (cohort 1: hazard ratio [HR] = 1.92; cohort 2: HR = 2.51, and cohort 3: HR = 1.69). Corresponding progression risks at 5 yr were 18%, 20%, and 18% for HG/G3 versus 7.3%, 7.5%, and 9.3% for HG/G2, respectively. Cox models using hybrid grade performed better than models with WHO2004/2016 (all cohorts; p < 0.001). For the three cohorts, C-indices for WHO2004/2016 were 0.69, 0.62, and 0.75, while, for hybrid grade, C-indices were 0.74, 0.68, and 0.78, respectively. Subdividing the HG category into HG/G2 and HG/G3 stratifies time to progression and supports the recommendation to adopt the hybrid grading system for Ta/T1 bladder cancers.
RESUMEN
BACKGROUND: Noncompliance with evidence-based interventions and guidelines contributes to significant and variable recurrence and progression in patients with non-muscle-invasive bladder cancer (NMIBC). The implementation of a quality performance indicator (QPI) programme in Scotland's National Health Service (NHS) aimed to improve cancer outcomes and reduce nationwide variance. OBJECTIVE: To evaluate the effect of hospitals achieving benchmarks for two specific QPIs on time to recurrence and progression in NMIBC. DESIGN, SETTING, AND PARTICIPANTS: QPIs for bladder cancer (BC) were enforced nationally in April 2014. NHS health boards collected prospective data on all new BC patients. Prospectively recorded surveillance data were pooled from 12 collaborating centres. INTERVENTION: QPIs of interest were (1) hospitals achieving detrusor muscle (DM) sampling target at initial transurethral resection of bladder tumour (TURBT) and (2) use of single instillation of mitomycin C after TURBT (SI-MMC). OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: The primary and secondary endpoints were time to recurrence and progression, respectively. Kaplan-Meier and Cox multivariable regression analyses were performed. KEY FINDINGS AND LIMITATIONS: Between April 1, 2014 and March 31, 2017, we diagnosed 3899 patients with new BC, of which 2688 were NMIBC . With a median follow up of 60.3 mo, hospitals achieving the DM sampling target had a 5.4% lower recurrence rate at 5 yr than hospitals not achieving this target (442/1136 [38.9%] vs 677/1528 [44.3%], 95% confidence interval [CI] = 1.6-9.2, p = 0.005). SI-MMC was associated with a 20.4% lower recurrence rate (634/1791 [35.4%] vs 469/840 [55.8%], 95% CI = 16.4-24.5, p < 0.001). On Cox multivariable regression, meeting the DM target and SI-MMC were associated with significant improvement in recurrence (hazard ratio [HR] 0.81, 95% CI = 0.73-0.91, p = 0.0002 and HR 0.66, 95% CI = 0.59-0.74, p < 0.004, respectively) as well as progression-free survival (HR 0.62, 95% CI = 0.45-0.84, p = 0.002 and HR 0.65, 95% CI = 0.49-0.87, p = 0.004, respectively). We did not have a national multicentre pre-QPI control. CONCLUSIONS: Within a national QPI programme, meeting targets for sampling DM and SI-MMC in the real world were independently associated with delays to recurrence and progression in NMIBC patients. PATIENT SUMMARY: Following the first 3 yr of implementing a novel quality performance indicator programme in Scotland, we evaluated compliance and outcomes in non-muscle-invasive bladder cancer. In 2688 patients followed up for 5 yr, we found that achieving targets for sampling detrusor muscle and the single instillation of mitomycin C during and after transurethral resection of bladder tumour, respectively, were associated with delays in cancer recurrence and progression.