From free-text electronic health records to structured cohorts: Onconum, an innovative methodology for real-world data mining in breast cancer.

Purpose: A considerable amount of valuable information is present in electronic health records (EHRs) however it remains inaccessible because it is embedded into unstructured narrative documents that cannot be easily analyzed. We wanted to develop and evaluate a methodology able to extract and structure information from electronic health records in breast cancer.

Methods: We developed a software platform called Onconum (ClinicalTrials.