Performance of externally validated machine learning models based on histopathology images for the diagnosis, classification, prognosis, or treatment outcome prediction in female breast cancer: A systematic review

Ricardo Gonzalez; Peyman Nejat; Ashirbani Saha; Clinton J V Campbell; Andrew P Norgan; Cynthia Lokker

doi:10.1016/j.jpi.2023.100348

Performance of externally validated machine learning models based on histopathology images for the diagnosis, classification, prognosis, or treatment outcome prediction in female breast cancer: A systematic review

J Pathol Inform. 2023 Nov 5:15:100348. doi: 10.1016/j.jpi.2023.100348. eCollection 2024 Dec.

Authors

Ricardo Gonzalez^{1

2}, Peyman Nejat³, Ashirbani Saha^{4

5}, Clinton J V Campbell^{6

7}, Andrew P Norgan⁸, Cynthia Lokker⁹

Affiliations

¹ DeGroote School of Business, McMaster University, Hamilton, Ontario, Canada.
² Division of Computational Pathology and Artificial Intelligence, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States.
³ Department of Artificial Intelligence and Informatics, Mayo Clinic, Rochester, MN, United States.
⁴ Department of Oncology, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada.
⁵ Escarpment Cancer Research Institute, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, Canada.
⁶ William Osler Health System, Brampton, Ontario, Canada.
⁷ Department of Pathology and Molecular Medicine, Faculty of Health Sciences, McMaster University, Hamilton, Ontario, Canada.
⁸ Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN, United States.
⁹ Health Information Research Unit, Department of Health Research Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada.

Abstract

Numerous machine learning (ML) models have been developed for breast cancer using various types of data. Successful external validation (EV) of ML models is important evidence of their generalizability. The aim of this systematic review was to assess the performance of externally validated ML models based on histopathology images for diagnosis, classification, prognosis, or treatment outcome prediction in female breast cancer. A systematic search of MEDLINE, EMBASE, CINAHL, IEEE, MICCAI, and SPIE conferences was performed for studies published between January 2010 and February 2022. The Prediction Model Risk of Bias Assessment Tool (PROBAST) was employed, and the results were narratively described. Of the 2011 non-duplicated citations, 8 journal articles and 2 conference proceedings met inclusion criteria. Three studies externally validated ML models for diagnosis, 4 for classification, 2 for prognosis, and 1 for both classification and prognosis. Most studies used Convolutional Neural Networks and one used logistic regression algorithms. For diagnostic/classification models, the most common performance metrics reported in the EV were accuracy and area under the curve, which were greater than 87% and 90%, respectively, using pathologists' annotations/diagnoses as ground truth. The hazard ratios in the EV of prognostic ML models were between 1.7 (95% CI, 1.2-2.6) and 1.8 (95% CI, 1.3-2.7) to predict distant disease-free survival; 1.91 (95% CI, 1.11-3.29) for recurrence, and between 0.09 (95% CI, 0.01-0.70) and 0.65 (95% CI, 0.43-0.98) for overall survival, using clinical data as ground truth. Despite EV being an important step before the clinical application of a ML model, it hasn't been performed routinely. The large variability in the training/validation datasets, methods, performance metrics, and reported information limited the comparison of the models and the analysis of their results. Increasing the availability of validation datasets and implementing standardized methods and reporting protocols may facilitate future analyses.

Keywords: Breast neoplasms; Machine learning; Pathology; Systematic review; Validation studies.

Publication types

Review