Histologic classification of
pathology specimens through
machine learning is a nascent field which offers tremendous potential to improve
cancer medicine. Its utility has been limited, in part because of differences in
tissue preparation and the relative paucity of well-annotated images. We introduce tissue recognition, an
unsupervised learning problem analogous to human face recognition, in which the goal is to identify individual tumors using a learned set of histologic features. This
feature set is the “tissue
fingerprint.” Because only specimen identities are matched to fingerprints, constructing an
algorithm for producing them is a self-learning task that does not need image
metadata annotations. Here, we provide an
algorithm for self-learning tissue fingerprints, that, in conjunction with
color normalization, can match hematoxylin and
eosin stained tissues to one of 104 patients with 93% accuracy. We applied this identification network's internal representation as a tissue
fingerprint for use in predicting the molecular status of an individual tumor (
breast cancer clinical
estrogen receptor (ER) status). We describe a
fingerprint-based classifier that predicts ER status from whole-slides with high accuracy (AUROC=0.90), and is an improvement over traditional transfer learning approaches. The use of tissue fingerprinting for
digital pathology as a concise but meaningful histopathologic
image representation enables a new range of
machine learning algorithms leading to increased information for
clinical decision making
in patient management.