Plasmacytoid Urothelial Carcinoma: Response to Chemotherapy and Oncologic Outcomes

Abstract

BACKGROUND: Plasmacytoid urothelial carcinoma is a rare bladder cancer variant with scarce data on outcomes and prognostic factors. OBJECTIVE: We report our institutional experience with this histology to determine response to neoadjuvant chemotherapy, definitive surgery and survival. METHODS: We conducted a retrospective chart review of consecutive patients with plasmacytoid, as well as conventional urothelial carcinoma (for comparison) seen in our institution (2007-2018). Baseline characteristics, clinicopathologic and treatment data were captured. T-test, chi-squared and log-rank test was used for group comparison. Kaplan Meier method was used for estimation of overall survival and Cox regression for identification of prognostic factors. RESULTS: 64 patients with plasmacytoid and 418 with conventional urothelial histology were identified; 53% of those with plasmacytoid presented with cT3/4 stage and 67% underwent extirpative surgery. Patients with plasmacytoid histology had higher rates of pT3/4 (65% vs. 28%), nodal disease (37% vs. 16%) and positive surgical margins (23% vs. 5%) compared to urothelial group (p < 0.01), as well as higher incidence of post-operative recurrence (47% vs. 29%, p = 0.05) and lower ypT0N0 rates after neoadjuvant chemotherapy (10% vs. 33%, p = 0.03). Plasmacytoid histology was associated with lower median overall survival compared to conventional urothelial (24 vs. 154 months, p < 0.01). CONCLUSIONS: Plasmacytoid urothelial carcinoma frequently presented with advanced stage at diagnosis and extirpative surgery, poor pathologic response to neoadjuvant chemotherapy, and inferior outcomes, when compared to conventional urothelial. Prospective trials evaluating upfront cystectomy versus preoperative chemotherapy and/or novel treatments should be considered.

Plasmacytoid Variant of Urothelial Carcinoma: Poor Prognostic Variant with High Expression of CDH1 Mutation

“…However, chemotherapy, which has been historically used for conventional or pure urothelial cancers, has often been used with relatively good success in PVUC, although the durability of response is often lacking [6]. However, a few reports have shown inconsistent benefit from the use of neoadjuvant or adjuvant chemotherapy [16][17][18], often used whenever possible, followed by consolidative surgery as the main therapeutic option of choice. In a retrospective study of 31 patients with PVUC, pathological down-staging was found in 80% of patients with resectable disease compared to the upstaging found in most patients who received surgery up-front.…”

Bladder Cancer Variant Histologies: Epidemiology, Diagnosis, Treatment and Prognosis

“…Mutations in CDH1 are pathognomonic of PUC and result in the loss of E-cadherin expression in its tumour cells, this is thought to explain the higher rates of tumour cell migration observed [34,35].…”

Current Management of Localized Muscle-Invasive Bladder Cancer: A Consensus Guideline from the Genitourinary Medical Oncologists of Canada

“…Urachal adenocarcinoma is covered in a separate review by the CUA and GUMOC [197]. Supporting evidence for OS benefit of NAC is limited or has conflicting results in micropapillary [198][199][200][201][202], plasmacytoid [203][204][205][206][207][208], nested [209,210], and sarcomatoid variants [177,[211][212][213], thus recommendations cannot be made in these settings at this time. Local definitive therapy may be the most important component of curative therapy.…”