PD63-11: Oncological Outcomes of cT1 Micropapillary Bladder Cancer Compared with cT2 Conventional Urothelial Carcinoma Treated with Radical Cystectomy

Monday, September 13, 2021 8:00 PM to 10:00 PM
Abstract

Information

Authors: Kevin Ginsburg, Akhil Chandra, Nicole Murray, Elizabeth Handorf, Laura Bukavina, David Chen, Richard Greenberg, Rosalia Viterbo, Robert Uzzo, Alexander Kutikov, Marc Smaldone, Andres Correa

Introduction: The management of patients with high risk non-muscle invasive urothelial carcinoma (UC) is complex due to the biological heterogeneity of the disease. The management of micropapillary (MP) bladder cancer, which commonly present at advanced stages, pose a significant treatment dilemma when diagnosed in the non-muscle invasive setting. We investigated the oncological outcomes of cT1 MP bladder cancer compared with cT2 conventional UC in patients treated with early radical cystectomy.

Methods: We reviewed the National Cancer Database for patients undergoing RC for cT1 MP and conventional cT1/cT2 UC from 2004 to 2016. We fit multivariable models to test for an association between histology and clinical T stage with OS, pathologically node positive disease (pN+), and upgrading to pT3/4 disease at RC. Models were adjusted for the use of systemic therapy, radiation therapy, comorbidity score, age, year of diagnosis, race, urban/rurality index, education status, income, sex, transfer status, distance from treating facility, and facility type. cT2 UC served as the reference category.

Results: We identified 27,453 patients that met inclusions, of which 125 had cT1 MP, 7,017 cT1 UC, and 20,311 cT2 UC disease. Compared with patients with cT2 UC, patients with cT1 MP had similar OS (HR 0.74, 95% CI 0.54-1.01, p=0.059) while patients cT1 UC (HR 0.70, 95% CI 0.66-0.74, p<0.001) had improved OS. More patients with cT1 MP had pN+ disease (39%) compared with patients with cT1 and cT2 UC (11% and 19%, respectively). After adjustment in the multivariable model, compared with patients with cT2 UC, patients with cT1 MP had increased odds of pN+ disease (OR 1.74, 95% CI 1.15-2.64, p=0.009) while patients with cT1 TC had decreased odds of pN+ disease (OR 0.76, 95% CI 0.70-0.83, p<0.001). More patients with cT1 MP were upstaged to pT3/4 at RC (31%) compared with patients with cT1 and cT2 UC (18% and 27%, respectively). After adjustment in the multivariable model, compared with patients with cT2 UC, patients with cT1 MP experienced similar odds of upstaging to pT3/4 at RC (OR 0.96, 95% CI 0.63-1.44, p=0.830) while upstaging was less common in patients with cT1 UC (OR 0.60, 95% CI 0.55-0.65, p<0.001).

Conclusions: In patients treated with RC, patients with cT1 MP had similar or worse oncological outcomes compared with patients with cT2 UC, while patients with cT1 UC had consistently favorable outcomes compared with patients with cT2 UC. These comparisons may help patients and clinicians while debating treatment options in those with cT1 MP bladder cancer.

Source of Funding: None
Therapeutic Area
Oncology: Bladder/Urothelium/Urethra