Mobile application-based Seoul National University Prostate Cancer Risk Calculator: development, validation, and comparative analysis with two Western risk calculators in Korean men

Abstract

Objectives: We developed a mobile application-based Seoul National University Prostate Cancer Risk Calculator (SNUPC-RC) that predicts the probability of prostate cancer (PC) at the initial prostate biopsy in a Korean cohort. Additionally, the application was validated and subjected to head-to-head comparisons with internet-based Western risk calculators in a validation cohort. Here, we describe its development and validation.

Patients and methods: As a retrospective study, consecutive men who underwent initial prostate biopsy with more than 12 cores at a tertiary center were included. In the development stage, 3,482 cases from May 2003 through November 2010 were analyzed. Clinical variables were evaluated, and the final prediction model was developed using the logistic regression model. In the validation stage, 1,112 cases from December 2010 through June 2012 were used. SNUPC-RC was compared with the European Randomized Study of Screening for PC Risk Calculator (ERSPC-RC) and the Prostate Cancer Prevention Trial Risk Calculator (PCPT-RC). The predictive accuracy was assessed using the area under the receiver operating characteristic curve (AUC). The clinical value was evaluated using decision curve analysis.

Results: PC was diagnosed in 1,240 (35.6%) and 417 (37.5%) men in the development and validation cohorts, respectively. Age, prostate-specific antigen level, prostate size, and abnormality on digital rectal examination or transrectal ultrasonography were significant factors of PC and were included in the final model. The predictive accuracy in the development cohort was 0.786. In the validation cohort, AUC was significantly higher for the SNUPC-RC (0.811) than for ERSPC-RC (0.768, p<0.001) and PCPT-RC (0.704, p<0.001). Decision curve analysis also showed higher net benefits with SNUPC-RC than with the other calculators.

Conclusions: SNUPC-RC has a higher predictive accuracy and clinical benefit than Western risk calculators. Furthermore, it is easy to use because it is available as a mobile application for smart devices.

Figure 1. Seoul National University prostate cancer calculator (Version 1.1).

(A) Main entry page of the calculator, (B) Selection page for “Prostate cancer risk calculator” or “Prostate cancer stage calculator”, and (C) Example of “Seoul National University prostate cancer risk calculator”.

Figure 2. Seoul National University prostate cancer risk nomogram for prostate cancer probability prediction in Korean men.

Figure 3. Calibration plot of the developed risk model.

Figure 4. The receiver operating characteristic curves for the different calculators evaluated.

Seoul National University prostate cancer risk calculator, European Randomized Study of Screening for Prostate Cancer Risk Calculator, and Prostate Cancer Prevention Trial Risk Calculator Were compared using the DeLong method.

Figure 5. Decision curve analysis for the calculators evaluated.

The Seoul National University prostate cancer risk calculator, European Randomized Study of Screening for Prostate Cancer Risk Calculator, and Prostate Cancer Prevention Trial Risk Calculator were analyzed.