Carcinoma Type Classification From High-Resolution Breast Microscopy Images Using a Hybrid Ensemble of Deep Convolutional Features and Gradient Boosting Trees Classifiers

Breast cancer is one of the main causes behind cancer deaths in women worldwide. Yet, owing to the complexity of the histopathological images and the arduousness of manual analysis task, the entire diagnosis process becomes time-consuming and the results are often contingent on the pathologist's subjectivity. Thus developing an automated, precise histopathological image classification system is crucial. This paper presents a novel hybrid ensemble framework consisting of multiple fine-tuned convolutional neural network (CNN) architectures as supervised feature extractors and eXtreme gradient boosting trees (XGBoost) as a top-level classifier, for patch wise classification of high-resolution breast histopathology images. Due to the semantic complexity of the patch images, a single CNN architecture may not always extract high quality features, and the traditional Softmax classifier might not provide ideal results for classifying the CNN extracted features. Thus we aim to improve patch wise classification by proposing a hybrid ensemble model that incorporates different discriminating feature representations of the patches, coupled with XGBoost for robust classification. Experimental results show that our proposed method outperforms state-of-the-art methods to the best of our knowledge.