Fig. 3

The boxplot of source site accuracies of DenseNet’s and KimiaNet’s deep features over 30 repeats within 5 cancer types with the highest numbers of WSIs. One can see that models trained on KimiaNet’s deep features are consistently more accurate than their counterparts in DenseNet. This finding suggests that KimiaNet’s deep features contain information about source sites of WSIs, although it was originally trained to distinguish cancer types and not source sites. It seems that this additional information, perhaps medically irrelevant, helps the network to classify cancer types due to the TCGA dataset’s internal biases. KIRC: Kidney Renal Carcinoma, PRAD: Prostate Adenocarcinoma, LUSC: Lung Squamous Cell Carcinoma, BRCA: Breast Carcinoma, THCA: Thyroid Carcinoma