A population-based retrospective analysis on variation in use of neoadjuvant chemotherapy depending on comorbidity in patients with muscle-invasive bladder cancer undergoing cystectomy in Denmark in the period 2013-2019

Neoadjuvant Chemotherapy in Muscle-Invasive Bladder Cancer: A Nationwide Analysis of Eligibility, Utilization, and Outcomes

OBJECTIVES

To investigate neoadjuvant chemotherapy (NAC) eligibility, utilization, and survival outcomes for muscle-invasive bladder cancer patients undergoing radical cystectomy (RC) in a Finnish population.

MATERIALS AND METHODS

Data from the Finnish National Cystectomy Database (2005-2017) was combined with Finnish Cancer Registry survival data. NAC utilization rates were reported, and downstaging rates were calculated based on final pathological staging. Logistic regression analyzed NAC usage and complete response (CR) predictors.

RESULTS

Since 2011, 29% of 1157 patients received NAC. Its usage remained consistent, and the number of eligible patients not receiving NAC decreased during the study period. Among NAC patients, pathology T-category was pT0 (34%), pT1-Ta-Tis (16%), pT2 (23%), pT3 (20%), and pT4 (7%) tumors, with pN0 in 82%. In the RC + NAC group, the 5-year overall survival (OS) rates were 89% for patients with no residual disease (pT0N0), 82% for those with organ-confined residual disease (pT1, Tis, Ta, T2/N0), and 49% for patients with non-organ-confined residual disease (pT3+/N+). The corresponding cancer-specific survival (CSS) rates were 93%, 86%, and 57%, respectively. Patients with organ-confined residual disease after NAC had survival outcomes comparable to those who underwent RC alone. Higher age; odds ratio (OR) 0.93, [95% Confidence Interval (CI): 0.90-0.95] and Charlson Co-morbidity Index-score [OR 0.88 (0.79-0.98)] reduced the likelihood of receiving NAC, while a smaller center size increased the probability [OR 1.82 (1.02-3.28)]. More treatment cycles [OR 0.70, (95% CI: 0.51-0.93)] and a favorable GFR [OR 0.38 (0.16-0.88)] were associated with achieving CR.

CONCLUSION

We report that NAC is well-utilized across Finland, with CR rates comparable to recent trials. Additionally, our survival rates are reasonable, and even with organ-confined residual disease after NAC, survival outcomes are similar to those who underwent RC alone.

DaBlaCa-17: nationwide observational study in Denmark on survival before and after implementation of neoadjuvant chemotherapy prior to cystectomy for muscle-invasive bladder cancer

OBJECTIVE

To investigate the impact of neoadjuvant chemotherapy implementation with gemcitabine-cisplatin on survival outcomes for patients with muscle-invasive bladder cancer in Denmark.

MATERIALS AND METHODS

Data were collected on all patients in Denmark undergoing radical cystectomy who were potential candidates for neoadjuvant chemotherapy from 2010 to 2015 (n = 851). A cohort before the implementation of neoadjuvant chemotherapy (Cohort 2010-12) was compared with a cohort after implementation (Cohort 2013-15). Patients in Cohort 2013-15 receiving neoadjuvant chemotherapy (+NAC, n = 213) were compared with patients in Cohort 2013-15 not receiving neoadjuvant chemotherapy (-NAC, n = 139). Pathological results after radical cystectomy and oncological outcomes were compared between the study cohorts. Overall survival, disease-free survival, and disease-specific survival were compared with Kaplan-Meier plots and with univariable and multivariable Cox regression. Kaplan-Meier estimates of overall survival were also performed separately for treating hospital and for pathological stage.

RESULTS

Pathological T0 (pT0) was more frequent in patients who received neoadjuvant chemotherapy: 34% versus 18% when comparing Cohort 2013-15 with Cohort 2010-12 (p < 0.001), and 46% versus 16% in +NAC compared with -NAC (p < 0.001). Overall survival, disease-free survival, and disease-specific survival at 5 years after cystectomy were not improved in Cohort 2013-15 compared with Cohort 2010-12 with adjusted hazard ratios of 1.11 (95% confidence interval [CI]: 0.87-1.43), 1.02 (95% CI: 0.81-1.29), and 1.06 (95% CI: 0.80-1.41), respectively.

CONCLUSIONS

This observational study found no improved survival in a national cohort of patients with muscle-invasive bladder cancer undergoing radical cystectomy after implementation of NAC. However, reservations should be made regarding the study design and the true effect of NAC on survival outcomes.

Circulating Tumor DNA Analysis in Advanced Urothelial Carcinoma: Insights from Biological Analysis and Extended Clinical Follow-up

PURPOSE

To investigate whether circulating tumor DNA (ctDNA) assessment in patients with muscle-invasive bladder cancer predicts treatment response and provides early detection of metastatic disease.

EXPERIMENTAL DESIGN

We present full follow-up results (median follow-up: 68 months) from a previously described cohort of 68 neoadjuvant chemotherapy (NAC)-treated patients who underwent longitudinal ctDNA testing (712 plasma samples). In addition, we performed ctDNA evaluation of 153 plasma samples collected before and after radical cystectomy (RC) in a separate cohort of 102 NAC-naïve patients (median follow-up: 72 months). Total RNA sequencing of tumors was performed to investigate biological characteristics of ctDNA shedding tumors.

RESULTS

Assessment of ctDNA after RC identified metastatic relapse with a sensitivity of 94% and specificity of 98% using the expanded follow-up data for the NAC-treated patients. ctDNA dynamics during NAC was independently associated with patient outcomes when adjusted for pathologic downstaging (HR = 4.7; P = 0.029). For the NAC-naïve patients, ctDNA was a prognostic predictor before (HR = 3.4; P = 0.0005) and after RC (HR = 17.8; P = 0.0002). No statistically significant difference in recurrence-free survival for patients without detectable ctDNA at diagnosis was observed between the cohorts. Baseline ctDNA positivity was associated with the Basal/Squamous (Ba/Sq) subtype and enrichment of epithelial-to-mesenchymal transition and cell cycle-associated gene sets.

CONCLUSIONS

ctDNA is prognostic in NAC-treated and NAC-naïve patients with more than 5 years follow-up and outperforms pathologic downstaging in predicting treatment efficacy. Patients without detectable ctDNA at diagnosis may benefit significantly less from NAC, but additional studies are needed.

Downstaging and survival after Neoadjuvant chemotherapy for bladder cancer in Norway; a population-based study

BACKGROUND

Neoadjuvant chemotherapy (NAC) before radical cystectomy is associated with pathological downstaging (DS) and improved overall survival (OS) in patients with muscle-invasive bladder cancer (MIBC). Population-based studies have not unequivocally shown improved survival. The aim of this population-based study was to evaluate the effect of NAC on DS and OS in Norwegian patients with MIBC.

METHODS

Patients in the Cancer Registry of Norway undergoing radical cystectomy (2008-2015) with or without NAC diagnosed with MIBC between 2008 and 2012 were included. Follow-up data were available until 31 December 2019. Logistic regression estimated the odds of DS with NAC, and a Cox model investigated the effect of DS on OS. Cox models, a mediator analysis and an instrumental variable approach were used to investigate the effect of NAC on OS.

RESULTS

A total of 575 patients were included. NAC was administered to 82 (14%) patients. Compared to cystectomy only, NAC increased the proportion (43% vs. 22%) and the odds of DS (OR 2.51, CI 1.37-4.60, p = 0.003). Independent of NAC, the proportion of pN0 was higher in patients with DS (89% vs. 60%) and DS yielded a 78% mortality risk reduction (HR 0.22, CI 0.15-0.34, p = 1.9∙10-12), compared to patients without DS. We did not find an association between NAC and OS, neither by Cox regression (HR 1.16, CI 0.80-1.68, p = 0.417) nor by an instrumental variable approach (HR = 0.56, CI = 0.07-4.57, p = 0.586). The mediation analysis (p = 0.026) confirmed an indirect effect of NAC on OS through DS. Limitations include limited information of the primary tumour, details of NAC treatment and treatment indications.

CONCLUSIONS

NAC increases the probability of DS and is indirectly associated to OS. DS is related to the absence of regional lymph node metastases and is associated with an OS benefit. Improved staging and biomarkers are needed to identify patients most likely to achieve DS and to benefit from NAC.