Bladder papillary urothelial neoplasm of low malignant potential in Chinese: a clinical and pathological analysis.

Papillary urothelial neoplasm of low malignant potential (PUNLMP) had the incidence of low and definitive recurrence. Therefore, few studies showed that the relationship between pathological factors and the prognosis of patients with PUNLMP. The aim of this study assessed the linkage of pathological factors and prognosis of patients with PUNLMP including the presence or absence of mitoses and the thickness of urothelium. A retrospective analysis of 71 patients with PUNLMP was enrolled between January 2007 and June 2013. The clinicopathological factors consisting of tumor diameter, multifocality, the presence or absence of mitoses and cell thickness of urothelium were retrieved, Log-rank test and Cox proportional hazards regression models were used for univariate and multivariate analyses to evaluate the associations of these factors with recurrence-free survival (RFS) and progression-free survival (PFS).The incidence of recurrence and progression for PUNLMP was 19.7% and 16.9%, respectively. Patients with grade progression represented 85.7% in the recurrent patients. No patients had stage progression and no cases died from invasive urothelial carcinoma. Univariate analysis showed that the presence of mitoses, tumor diameter greater than or equal to 0.8 cm, multifocality were significantly correlated with worse RFS (P<0.05) and PFS (P<0.05). Multivariate analysis demonstrated that the presence of mitoses, tumor multifocality were significantly independent biomarkers for worse RFS (P<0.05) and PFS (P<0.05). Although the rare and infrequent mitoses were found for PUNLMP, the presence of mitoses and tumor multifocality were still the independent and poor predictors for the prognosis of PUNLMP. In addition, once the PUNLMP appeared to the recurrence, the inevitable grade progression could be determined, herein, long-term follow-up was necessary to be warranted, especially for patients with multiple lesions and the presence of mitoses.