Perivesical Fat Invasive Pattern as Prognostic Factor and Predictor of Response to Adjuvant Chemotherapy in T3 Stage Bladder Cancer.

Background: The prognostic value of the distinction between microscopic (pT3a) and macroscopic (pT3b) perivesical fat invasions remains a subject of debate. To explore whether the pattern of perivesical fat invasion can serve as a prognostic factor to better subgroup T3 stage bladder cancer.

Materials And Methods: One hundred and forty-nine patients diagnosed with T3 stage bladder cancer at Sun Yat-sen University Cancer Center (SYSUCC) were selected for the experimental cohort in this study. Ninety-seven T3 stage bladder cancer patients with pathological slices at the Cancer Genome Atlas (TCGA) were selected as validation cohort in this study. The perivesical fat invasive pattern was examined with hematoxylin and eosin-stained pathological slides by two pathologists independently. Two different perivesical fat invasive patterns, fibrous-surrounded (FS) pattern, and nonfibrous-surrounded (NFS) pattern were assessed.

Results: Perivesical fat invasion pattern had a significant influence on overall survival in T3 stage bladder cancer. Compared to the NFS pattern, the FS pattern was related to a better prognosis in both the SYSUCC cohort and TCGA cohort. The patients with NFS pattern tumor who underwent cisplatin-based adjuvant chemotherapy experienced an obvious improvement compared to observation after radical cystectomy in overall survival in the SYSUCC cohort.

Conclusion: The perivesical fat invasion pattern could predict prognosis and clinically different chemotherapeutic survival outcomes in patients with T3 stage bladder cancer after radical cystectomy.