Developing a prediction model for disease‐free survival from upper urinary tract urothelial carcinoma in the Korean population

Abstract

Background In this study, we aimed to propose a validated prediction model for disease‐free survival (DFS) after radical nephroureterectomy (RNU) in a Korean population with upper urinary tract urothelial carcinoma (UTUC). Methods We performed a retrospective review of 1561 cases of UTUC who underwent either open RNU (ONU, n = 906) or laparoscopic RNU (LNU, n = 615) from five tertiary Korean institutions between January 2000 and December 2012. Data were used to develop a prediction model using the Cox proportional hazards model. Prognostic factors were selected using the backward variable selection method. The prediction model performance was investigated using Harrell's concordance index (C‐index) and Hosmer‐Lemeshow type 2 statistics. Internal validation was performed using a bootstrap approach, and the National Cancer Center data set (n = 128) was used for external validation. Results A best‐fitting prediction model with seven significant factors was developed. The C‐index and two Hosmer‐Lemeshow type statistics of the prediction model were 0.785 (95% CI, 0.755‐0.815), 4.810 ( P = 0.8506), and 5.285 ( P = 0.8088). The optimism‐corrected estimate through the internal validation was 0.774 (95% CI, 0.744‐0.804) and the optimism‐corrected calibration curve was close to the ideal line with mean absolute error = 0.012. In external validation, the discrimination was 0.657 (95% CI, 0.560‐0.755) and the two calibration statistics were 0.790 ( P = 0.9397) and 3.103 ( P = 0.5408), respectively. Conclusion A validated prediction model based on a large Korean RNU cohort was developed with acceptable performance to estimate DFS in patients with UTUC.

Incidence and survival variations of upper tract urothelial cancer in Taiwan (2001–2010)

“…The overall 5‐year overall survival probability in Taiwan is comparable with those reported in Western countries and Japan, 3,22,23 and is better than those reported in Australia 5 . Tumor stage and age have been considered as key determinants in explaining the difference of UTUC outcomes within one country 24,25 . Although patients with UTUC in Taiwan and China were significantly younger, typically female, and had a lower tumor stage than those in Japan and the USA, previous studies found similar prognoses between these countries, suggesting that international UTUC treatments and care are of comparable quality 23,26 .…”

“… 5 Tumor stage and age have been considered as key determinants in explaining the difference of UTUC outcomes within one country. 24 , 25 Although patients with UTUC in Taiwan and China were significantly younger, typically female, and had a lower tumor stage than those in Japan and the USA, previous studies found similar prognoses between these countries, suggesting that international UTUC treatments and care are of comparable quality. 23 , 26 In contrast to the findings of the present systematic review, men had a poorer overall survival rate, possibly because women with UTUC in Taiwan are healthier compared with those in other countries due to unique causes.…”