To improve the clinical decision-making regarding further treatment management
and follow-up scheduling for patients with muscle-invasive bladder cancer
(MIBC) after radical cystectomy (RC), a better prediction accuracy of
prognosis for these patients is urgently needed. The objective of this study
was to evaluate the validity of differentially expressed microRNAs (miRNAs)
based on a previous study as prognostic markers for overall survival (OS)
after RC in models combined with clinicopathological data. The expression of
six miRNAs (miR-100-5p, miR-130b-3p, miR-141-3p, miR-199a-3p, miR-205-5p, and
miR-214-3p) was measured by RT-qPCR in formalin-fixed, paraffin-embedded
tissue samples from 156 MIBC patients who received RC in three urological
centers. Samples from 2000 to 2013 were used according to their tissue
availability, with follow-up until June 2016. The patient cohort was randomly
divided into a training (n = 100) and test set (n = 56). Seventy-three samples
from adjacent normal tissue were used as controls. Kaplan–Meier, univariate
and multivariate Cox regression, and decision curve analyses were carried out
to assess the association of clinicopathological variables and miRNAs to OS.
Both increased (miR-130b-3p and miR-141-3p) and reduced (miR-100-5p, miR-199a-
3p, and miR-214-3p) miRNA expressions were found in MIBC samples in comparison
to nonmalignant tissue samples (P < 0.0001). miR-199a-3p and miR-214-3p were
independent markers of OS in Cox regression models with the significant
clinicopathological variables age, tumor status, and lymph node status. The
prediction model with the clinicopathological variables was improved by these
two miRNAs in both sets. The predictive benefit was confirmed by decision
curve analysis. In conclusion, the inclusion of both miRNAs into models based
on clinical data for the outcome prediction of MIBC patients after RC could be
a valuable approach to improve prognostic accuracy
