External validation and comparison of two nomograms predicting the probability of Gleason sum upgrading between biopsy and radical prostatectomy pathology in two patient populations: a retrospective cohort study

The aim of this study is to validate and compare the predictive accuracy of two nomograms predicting the probability of Gleason sum upgrading between biopsy and radical prostatectomy pathology among representative patients with prostate cancer.

We previously developed a nomogram, as did Chun et al. In this validation study, patients originated from two centers: Toho University Sakura Medical Center (n = 214) and Chibaken Saiseikai Narashino Hospital (n = 216). We assessed predictive accuracy using area under the curve values and constructed calibration plots to grasp the tendency for each institution. Both nomograms showed a high predictive accuracy in each institution, although the constructed calibration plots of the two nomograms underestimated the actual probability in Toho University Sakura Medical Center. Clinicians need to use calibration plots for each institution to correctly understand the tendency of each nomogram for their patients, even if each nomogram has a good predictive accuracy.

Japanese journal of clinical oncology 2015 Aug 19 [Epub ahead of print]

Takanobu Utsumi, Ryo Oka, Takumi Endo, Masashi Yano, Shuichi Kamijima, Naoto Kamiya, Masaaki Fujimura, Nobuyuki Sekita, Kazuo Mikami, Nobuyuki Hiruta, Hiroyoshi Suzuki

Department of Urology, Toho University Sakura Medical Center, Sakura-shi takanobu utsumi@med toho-u ac jp , Department of Urology, Toho University Sakura Medical Center, Sakura-shi , Department of Urology, Toho University Sakura Medical Center, Sakura-shi , Department of Urology, Toho University Sakura Medical Center, Sakura-shi , Department of Urology, Toho University Sakura Medical Center, Sakura-shi , Department of Urology, Toho University Sakura Medical Center, Sakura-shi , Department of Urology, Chibaken Saiseikai Narashino Hospital, Narashino-shi , Department of Urology, Chibaken Saiseikai Narashino Hospital, Narashino-shi , Department of Urology, Chibaken Saiseikai Narashino Hospital, Narashino-shi , Department of Pathology, Toho University Sakura Medical Center, Sakura-shi, Japan , Department of Urology, Toho University Sakura Medical Center, Sakura-shi

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