Login to Access Video or Poster Abstract: MP21-20
Sources of Funding: Supported in part by the Sidney Kimmel Center for Prostate and Urologic Cancers, funds from T32 CA082088, and P30 CA008748.

Introduction

To compare clinical outcomes of patients with any component of plasmacytoid variant(PCV) of urothelial carcinoma with that of patients with pure urothelial carcinoma (UC) treated with radical cystectomy (RC).

Methods

We identified 98 patients who had pathologically confirmed PCV on transurethral resection or RC and 1312 patients with pure UC and no variant history who underwent RC at our institution between January 1995 and December 2014. Univariable and multivariable Cox regression and Cox proportional hazards regression to determine if PCV histology was associated with overall survival (OS).

Results

Patients with PCV were younger (p=0.012), more likely to have advanced tumor stage (pT3/pT4, p=0.002), positive lymph nodes (p=0.038), and receive neoadjuvant chemotherapy than those with pure UC (45% versus 21%, p<0.0001). Rate of positive soft tissue surgical margins was over five times greater in the PCV group compared with the pure UC group (22% versus 4%, respectively, p<0.0001). Median OS for the pure UC group vs the PCV group were 8 and 3.8 years, respectively. On univariable analysis, PCV histology was associated with an increased risk of overall mortality (HR=1.34; 95% CI 1.02–1.78; p=0.039). However, on multivariable analysis adjusted for age, gender, neoadjuvant chemotherapy received, lymph node status, and pathologic stage, the association between PCV and OS was no longer significant (HR=1.13; 95% CI 0.84–1.51; p=0.4).

Conclusions

Patients with PCV features have higher disease burden at RC compared with those with pure UC. However, PCV was not an independent predictor of survival after RC on multivariable analysis, suggesting that PCV histology cannot be used as a prognostic factor.

Funding

Supported in part by the Sidney Kimmel Center for Prostate and Urologic Cancers, funds from T32 CA082088, and P30 CA008748.