Prognostic implication of infiltrative growth pattern and establishment of novel risk stratification model for survival in patients with upper urinary tract urothelial carcinoma

Abstract

To investigate the prognostic significance of infiltrative growth pattern (INF) and to develop a novel risk stratification model for disease-specific survival (DSS) in patients with upper urinary tract urothelial carcinoma (UTUC). This study included 113 patients with UTUC treated with radical nephroureterectomy. Pathological features, including INF, were compared with DSS. INF was classified into 3 patterns (INFa, INFb, and INFc). The prognostic factors of DSS were evaluated with univariate and multivariate Cox proportional hazard model analyses. A risk stratification model based on the relative risks of DSS was then established. Univariate analysis revealed that patients with high-grade tumor, pathological T stage ≥T3, a non-expanding infiltration pattern (INF ≥b), sessile-type carcinoma, the presence of lymphovascular invasion and positive lymph node involvement showed significantly lower survival rates than their respective counterparts. In the multivariate analysis, high grade tumor, positive lymph node involvement and INF ≥b were independent predictors for DSS (p < 0.05). The patients were stratified into 3 risk groups. The 5-year DSS rates were 94.4 % in the low-risk group, 67.5 % in the intermediate-risk group and 20.5 % in the high-risk group. In addition to lymph node involvement and pathological tumor grade, INF is a novel independent prognostic factor in patients with UTUC treated with radical nephroureterectomy. Our risk stratification model developed using these 3 factors may help clinicians identify patients with a poor prognosis who might be good candidates for clinical trials of innovative therapies.