External validation of two web-based postoperative nomograms predicting the probability of early biochemical recurrence after radical prostatectomy: a retrospective cohort study

The predictive accuracy of each web-based nomogram predicting early BCR after RP was fair in Japanese patients. Moreover, LVI, particularly ly, can become a good predictor for early BCR. Abstract The present study aimed to validate and compare the predictive accuracies of the Memorial Sloan Kettering Cancer Center (MSKCC) and Johns Hopkins University (JHU) web-based postoperative nomograms for predicting early biochemical recurrence (BCR) after radical prostatectomy (RP) and to analyze clinicopathological factors to predict early BCR after RP using our dataset. The c-index was 0.72 (95% confidence (CI): 0.61–0.83) for the MSKCC nomogram and 0.71 (95% CI: 0.61–0.81) for the and JHU nomogram, demonstrating fair performance in the Japanese population. Furthermore, we statistically analyzed our 174 patients to elucidate prognostic factors for early BCR within 2 years. Lymphovascular invasion (LVI) including lymphatic vessel invasion (ly) was a significant predictor of early BCR in addition to common variables (pT stage, extraprostatic extension, positive surgical margin and seminal vesicle invasion). LVI, particularly ly, may provide a good predictor of early BCR after RP and improve the accuracy of the nomograms.