Clinicopathologic factors, treatment patterns, and outcomes in micropapillary urothelial carcinoma (UC).

Abstract

439 Background: Micropapillary UC remains rare yet with an aggressive phenotype. Limited data exists regarding the optimal management of this variant in the contemporary era. Methods: A retrospective analysis was performed to identity patients (pts) with micropapillary UC at the Cleveland Clinic (1997-2017). Demographic, clinico-pathological, treatment regimens, and clinical outcomes, e.g. progression-free and overall survival (PFS and OS) data were collected. Results: A total of 102 pts with median age 70.5 (46-90) at diagnosis, 84%, men, 17% never smokers were identified. Stage at diagnosis for 68 pts with available data was T1 in 29, T2 in 36, T3 in 1, T4 in 2, N+ in 5, and M+ in 4 pts, respectively. Twelve pts were initially treated with intravesical therapy for NMIBC with 58% progressing to higher stage. Overall, 81% of pts had cystectomy; of those 19% had neoadjuvant chemotherapy (NAC; 81% cisplatin-based, median 3 cycles), 21 pts received adjuvant chemotherapy and 3 pts adjuvant radiation. Of 12 pts with available data, 4 had down-staging with NAC with 1 pCR. Pathologic stage was 0is, I, II, III, IV in 4%, 10%, 9%, 9%, and 67% respectively. Overall, 61 pts had recurrent or de-novo metastatic disease (most nodal/local-regional recurrence). For patients with recurrence post-surgery (n = 31), 35% received systemic chemotherapy, 16% had salvage surgery, 10% had salvage radiation, 19% had best supportive care, and the rest were lost to follow-up or refused treatment. The most common 1st-line regimen included platinum-doublet (46%), other combinations (23%), single-agent (23%) and immune checkpoint inhibitors (8%). Overall response (CR/PR) to 1st-line treatment was 38% and median PFS was 8 months (95%CI 0-16.4). Overall, 29 pts died with recurrent/metastatic disease with a median OS (from time of diagnosis) of 39.3 months (95%CI 28.4-50.2) Median OS (from time of diagnosis) for pts treated with cystectomy was 47.1 months (95%CI 23.9-50.2). Conclusions: Micropapillary UC was associated with advanced pathologic stage at cystectomy and limited use of NAC. Responses were noted with NAC and 1st line systemic treatment. Further validation can assist in prognostication and selection/stratification in future trials.

Histologic Variants of Urothelial Carcinoma: Morphology, Molecular Features and Clinical Implications

“…MP demonstrates aggressive clinical behavior with features including lymphovascular invasion (LVI), early lymph node metastases, and wide metastatic spread [29,36]. Interestingly, MP histology is also associated with poor prognosis in cases of lung, breast, pancreas, colon/rectum, and salivary gland carcinoma with this histologic pattern [33].…”