Impact of AIB1 expression on the prognosis of upper tract urothelial carcinoma after radical nephroureterectomy

BACKGROUND: Amplified in breast cancer 1 (AIB1) is a candidate oncogene in human breast cancer, which has been identified to be amplified and overexpressed in several types of other human cancers. Abnormalities of AIB1 and its clinical/prognostic significance, however, in upper tract urothelial carcinoma (UTUC) remain unclear. OBJECTIVE: To explore what role AIB1 plays in upper tract urothelial carcinoma. METHODS: The expression of AIB1 was analyzed using immunohistochemical staining in 133 UTUC patients. Overall, cancer specific and recurrence-free survival rates (OS, CSS, and RFS) were estimated using the Kaplan-Meier method. Multivariable COX regression models containing relevant clinicopathological variables addressed the prediction of postoperative outcome. RESULTS: High AIB1 expression was observed to be associated with increased hazard ratios for 5-year CSS (80.6% vs. 55.8%, p = 0.008) and OS (78.1% vs. 54.8%, p = 0.006). Multivariable analysis revealed that elevated AIB1 expression was an independent prognostic predictor of OS, CSS and RFS. Additionally, pT, pN and hydronephrosis were independently associated with oncologic outcome of UTUC. Three proposed nomograms were proposed to provide an individualized risk estimate of postoperative outcome in patients with UTUC. CONCLUSIONS: AIB1 can be used as an independent molecular marker for the prognosis of clinical outcomes of UTUC.