Bladder cancer following renal transplantation: experiences with radical cystectomy and adjuvant radiotherapy

369 Background: Historic trials suggested significant toxicity with adjuvant radiotherapy (ART) after radical cystectomy for muscle-invasive bladder cancer (MIBC). However, recent trials have found improved locoregional control and the 2016 NCCN guidelines recommend ART consideration for select patients at high risk of local recurrence. ART practice patterns among U.S. radiation oncologists (ROs) are unknown, and we performed a survey to explore current trends. Methods: We conducted a survey of U.S. ROs regarding the management of patients with cT2-3N0M0 transitional cell MIBC. Responses were reported using descriptive statistics. Chi-square and univariate logistic regression (UVA) of clinical and demographic covariates were conducted, followed by multivariable logistic regression analyses (MVA) to identify factors predicting for ART use. Results: 277 ROs completed our survey. Nearly half (46%) use ART for MIBC. In ART-users, indications for ART include gross residual disease (93%), positive margins (92%), pathologic nodal involvement (64%), pT3 or T4 disease (46%), lymphovascular invasion (16%), and high-grade disease (13%). On UVA, ART use was associated with the number of years in practice (p=.043), pre-cystectomy RO consultation (p=0.004), primarily treating MIBC patients fit for cystectomy (p=0.009), and intensity-modulated radiotherapy (IMRT) use (p=0.009). On MVA, routine pre-cystectomy RO consultation (odds ratio [OR] 1.91, 95% confidence interval [CI]: 1.04-3.51; p=.037) and IMRT use (OR 2.77, 95% CI: 1.48-5.22; p=.002) remained associated with ART use. Conclusions: ART use is controversial in bladder cancer, yet is unexpectedly commonly used among U.S. radiation oncologists treating patients with MIBC after radical cystectomy. NRG GU001 is a randomized trial currently accruing patients with high-risk pathologic findings for observation or ART after cystectomy, and will hopefully clarify the role of ART and help identify patients benefiting from this adjuvant therapy. Whenever possible, patients should be enrolled in this study.

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Effectiveness of adjuvant radiotherapy after radical cystectomy for locally advanced bladder cancer.

Journal of Clinical Oncology ◽

10.1200/jco.2018.36.6_suppl.484 ◽

2018 ◽

Vol 36 (6_suppl) ◽

pp. 484-484

Author(s):

Benjamin Walker Fischer-Valuck ◽

Jeff M. Michalski ◽

John Paul Christodouleas ◽

Eric Kim ◽

Todd A. DeWees ◽

...

Keyword(s):

Bladder Cancer ◽

Radical Cystectomy ◽

Adjuvant Radiotherapy ◽

Univariate Analysis ◽

Locally Advanced ◽

Surgical Margin ◽

High Morbidity ◽

Matched Cohort ◽

Positive Margins ◽

Advanced Bladder Cancer

484 Background: Local-regional failure (LF) for locally advanced bladder cancer (LABC) after radical cystectomy (RC) is common even with chemo and is associated with high morbidity/mortality. Adjuvant radiotherapy (adjRT) can reduce LF and may enhance overall survival (OS) but has no defined role. We hypothesized that the addition of adjRT would improve OS in LABC in a large multi-institutional cohort. Methods: We identified ≥pT3 pN0-3, M0 LABC pts in the NCDB diagnosed in 2004 – 2013 who underwent RC +/- adjRT. AdjRT cohort included pts treated to ≥40Gy to the pelvis within 1 yr of diagnosis. Propensity matching was performed to match RC pts who received adjRT vs. those who did not. OS was calculated using Kaplan-Meier. Factors significant on univariate analysis were entered into Cox proportional hazards regression model to identify predictors of OS. Results: 15,246 RC pts were identified, with 450 (3.0%) receiving adjRT. Median OS was 23.0 mo (95% CI, 22.4-23.6) for RC vs. 19.7 mo (95% CI, 17.7-21.7) for adjRT [Log-rank P = 0.002; Wilcoxon P = 0.862]. Propensity score matching on demographic, clinical, & treatment variables yielded 742 pts (371 in each group). In the matched cohort, OS was 17.1 mo [95%CI, 14.5 - 19.6] for RC vs. 20.1 mo [95% CI, 17.8– 22.5] for adjRT [Log-rank P = 0.044]. On MVA in the matched cohort, factors predictive of OS were sex, pT stage, pN+ status, surgical margin status, number of nodes removed, adjRT, & chemo (p < 0.01 for all). On MVA of subgroups, adjRT was associated with significantly improved OS in pts with positive margins [HR 0.55 (95% CI, 0.43 – 0.71), P < 0.001], pN+ disease [HR 0.62 (95% CI, 0.49 – 0.79), P < 0.001], & pT4 disease [HR 0.68 (95% CI, 0.55 – 0.85), P = 0.001]. In MVA of pts with urothelial carcinoma (N = 578), adjRT remained associated with improved OS in pts with positive margins [HR 0.57 (95% CI, 0.43 – 0.76), P < 0.001], pN+ disease [HR 0.65 (95% CI, 0.50 – 0.86), P = 0.002], & pT4 disease [HR 0.68 (95% CI, 0.54 – 0.85), P = 0.001]. Conclusions: In this observational study, adjRT was associated with improved OS in LABC. While the data should be interpreted cautiously, these results lend support to the use of adjRT in selected pts with LABC, regardless of histology. Prospective trials of adjRT are warranted.

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