Abstract
Only a few pathologists have the opportunity to verify their personal grading through objective assessment. This study introduces a web‐based grading platform to facilitate and validate the grading of renal cell carcinoma and prostate cancer. Two representative images of two clinically annotated cohorts of 100 cases each of prostate and renal cell carcinoma were used. Each participant was asked to grade a tumor series utilizing a three tiered grading system. Finally, a Kaplan–Meier curve was drawn, and the log‐rank test was used for statistical testing of the p‐value. The grading of 22 participants (68%) achieved prognostic significance. Further analysis highlighted that only two pathologists were able to reliably separate low‐ and high‐grade tumors from intermediate grades. The limitations of this study are the low number of participants in each of the cohorts and the potential selection bias of the tumor images. This web‐based grading portal facilitates the assessment of the validity of grading by individual pathologists. The observation that most participants can only successfully identify high‐ or low‐grade tumors but cannot discriminate between more subtle intermediate grades does indicate that there is a need for the development of more formal training programs for tumor grading.