Risk stratification for bladder recurrence of upper urinary tract urothelial carcinoma after radical nephroureterectomy.

OBJECTIVES: To identify risk factors and develop a model for predicting recurrence of upper urinary tract urothelial carcinoma (UTUC) in the bladder in patients without a history of bladder cancer after radical nephroureterectomy (RNU). PATIENTS AND METHODS: We retrospectively reviewed 754 patients with UTUC without prior or concurrent bladder cancer or distant metastasis at 13 institutions in Japan. Univariate and multivariate Fine and Gray competing risks proportional hazards models were used to examine the cumulative incidence of bladder recurrence of UTUC. A risk stratification model and a nomogram were constructed. Two prediction models were compared using the concordance index (c-index) focusing on predictive accuracy and decision-curve analysis, which indicate whether a model is appropriate for decision-making and determining subsequent patient prognosis. RESULTS: The cumulative incidence rates of bladder UTUC recurrence at 1 and 5 years were 15 and 29%, respectively; the median time to bladder UTUC recurrence was 10 months. Multivariate analysis showed that papillary tumour architecture, absence of lymphovascular invasion and higher pathological T stage were both predictive factors for bladder cancer recurrence. The predictive accuracy of the risk stratification model and the nomogram for bladder cancer recurrence were not different (c-index: 0.60 and 0.62). According to the decision-curve analysis, the risk stratification was an acceptable model because the net benefit of the risk stratification was equivalent to that of the nomogram. The overall cumulative incidence rates of bladder cancer 5 years after RNU were 10, 26 and 44% in the low-, intermediate- and high-risk groups, respectively. CONCLUSIONS: We identified risk factors and developed a risk stratification model for UTUC recurrence in the bladder after RNU. This model could be used to provide both an individualised strategy to prevent recurrence and a risk-stratified surveillance protocol.

Bimodal pattern of the impact of body mass index on cancer-specific survival of upper urinary tract urothelial carcinoma patients.

AIM: To clarify how body mass index (BMI) affects the risk of death from upper urinary tract urothelial carcinoma (UUTUC) we investigated the impact of BMI on UUTUC using a Japanese multicenter database. PATIENTS AND METHODS: Between January 1995 and December 2010, 1,329 patients with upper urinary tract tumors were treated in 13 institutions in Japan. From this group, a cohort of 1,014 patients treated with radical nephroureterectomy was retrospectively reviewed. BMI was categorized into the following three groups: BMI <22.5, BMI 22.5 to <25 and BMI ≥ 25. The association between each group and cancer-specific survival (CSS) was analyzed using Cox proportional hazards regression models. RESULTS: The median BMI was 22.4 kg/m(2) (interquartile range, 20.5-24.8). Out of all patients, 213 (21%) died of UUTUC. Hazard ratios of the BMI ≥ 25 and the BMI <22.5 group were 1.76 and 1.66, respectively. CONCLUSION: Both higher and lower BMI affect the prognosis of UUTUC treated with radical nephroureterectomy.