A deep learning system for prostate cancer diagnosis and grading in whole slide images of core needle biopsies

Gleason grading, a risk stratification method for prostate cancer, is subjective and dependent on experience and expertise of the reporting pathologist. Deep Learning (DL) systems have shown promise in enhancing the objectivity and efficiency of Gleason grading. However, DL networks exhibit domain shift and reduced performance on Whole Slide Images (WSI) from a source other than training data. We propose a DL approach for segmenting and grading epithelial tissue using a novel training methodology that learns domain agnostic features. In this retrospective study, we analyzed WSI from three cohorts of prostate cancer patients. 3741 core needle biopsies (CNBs) received from two centers were used for training. The kappa quad (quadratic-weighted kappa) and AUC were measured for grade group comparison and core-level detection accuracy, respectively. Accuracy of 89.4% and kappa quad of 0.92 on the internal test set of 425 CNB WSI and accuracy of 85.3% and kappa quad of 0.96 on an external set of 1201 images, was observed. The system showed an accuracy of 83.1% and kappa quad of 0.93 on 1303 WSI from the third institution (blind evaluation). Our DL system, used as an assistive tool for CNB review, can potentially improve the consistency and accuracy of grading, resulting in better patient outcomes.

Automated summary

The study proposed a deep learning approach to improve the objectivity and efficiency of prostate cancer tissue grading. The system demonstrated high accuracy and consistency on internal and external test sets, with potential implications for improving patient outcomes.