Preoperative Plasma Insulin-Like Growth Factor-I and Its Binding Proteins-Based Risk Stratification of Patients Treated With Radical Nephroureterectomy for Upper Tract Urothelial Carcinoma.

Introduction: We evaluate the predictive and prognostic value of insulin-like growth factor-I (IGF-1), IGF binding protein-2 (IGFBP-2) and -3 (IGFBP-3) in patients treated with radical nephroureterectomy (RNU) for upper tract urothelial carcinoma (UTUC).

Methods: This is a retrospective analysis of a multi-institutional database comprising 753 patients who underwent RNU for UTUC and had a preoperative plasma available. Logistic and Cox regression analyses were performed. The discriminative ability and clinical utility of the models was calculated using the lasso regression test, area under receiver operating characteristics curves, C-index, and decision curve analysis (DCA).

Results: Lower preoperative plasma levels of IGFBP-2 and -3 independently correlated with increased risks of lymph node metastasis, pT3/4 disease, nonorgan confined disease, and worse recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS) (all P ≤ .004). The addition of both IGFBP-2 and -3 to a postoperative multivariable model, that included standard clinicopathologic characteristics, improved the model's concordance index by 10%, 9%, and 8% for RFS, CSS, and OS, respectively. On DCA, addition of both IGFBP-2 and -3 to base models improved their performance for RFS, CSS, and OS by a statistically and clinically significant margin. Plasma IGF-1 was not associated with any of outcomes.

Conclusions: We confirmed that a lower plasma levels of IGFBP-2 and -3 both are independent and clinically significant predictors of adverse pathological features and survival outcomes in UTUC patients treated with RNU. These findings might help guide the clinical decision-making regarding perioperative systemic therapy and follow-up scheduling.