Genomic testing in early stage invasive male breast cancer: An NCDB analysis from 2008 to 2014

Analyzing Precision Medicine Utilization with Real-World Data: A Scoping Review

Precision medicine (PM), specifically genetic-based testing, is currently used in over 140,000 individual tests to inform the clinical management of disease. Though several databases (e.g., the NIH Genetic Testing Registry) demonstrate the availability of these sequencing-based tests, we do not currently understand the extent to which these tests are used. There exists a need to synthesize the body of real-world data (RWD) describing the use of sequencing-based tests to inform their appropriate use. To accomplish this, we performed a scoping review to examine what RWD sources have been used in studies of PM utilization between January 2015 and August 2021 to characterize the use of genome sequencing (GS), exome sequencing (ES), tumor sequencing (TS), next-generation sequencing-based panels (NGS), gene expression profiling (GEP), and pharmacogenomics (PGx) panels. We abstracted variables describing the use of these types of tests and performed a descriptive statistical analysis. We identified 440 articles in our search and included 72 articles in our study. Publications based on registry databases were the most common, followed by studies based on private insurer administrative claims. Slightly more than one-third (38%) used integrated datasets. Two thirds (67%) of the studies focused on the use of tests for oncological clinical applications. We summarize the RWD sources used in peer-reviewed literature on the use of PM. Our findings will help improve future study design by encouraging the use of centralized databases and registries to track the implementation and use of PM.

Subtyping of male breast cancer by PAM50 and immunohistochemistry: a pilot study of a consecutive Danish cohort

Male breast cancer (MBC) is a rare disease that is still to be fully understood. In female breast cancer, molecular subtyping by gene expression has proven its significance. In this study, we characterize a consecutive cohort of MBC patients surgically treated from 1997 to 2017, identified at our institution (N = 37), and report the association between molecular subtypes found by a surrogate panel of immunohistochemical (IHC) markers, and the PAM50 signature, as well as risk of recurrence score and overall survival for the different subtypes. PAM50 subtypes were determined using the nCounter FLEX system instrument and software. The distribution of molecular subtypes according to the PAM50 signature was as follows: 56% luminal B, 39% luminal A, and 5% basal-like. None of the tumors were HER2-enriched. Using IHC surrogate markers, we found 80% luminal B-like, 15% luminal A-like, and 5% basal-like. None were HER2-positive (non-luminal). We found a strong statistical association between subtypes found by PAM50 signature and the IHC surrogate markers (p < 0.001). Furthermore, we found luminal A tumors to be smaller in size compared to luminal B tumors (p = 0.04). Patients with luminal A subtype tumors had the lowest ROR scores with a mean of 39, whereas patients with luminal B subtype tumors had a mean ROR score of 69. Significant worse overall survival for luminal B tumors compared to luminal A tumors was seen (p = 0.02). Male breast cancer seems to be a mainly luminal disease, with luminal B being the most frequent subtype. Further studies are needed to ensure correct therapeutic strategies for this select group of patients.

Multigene testing in breast cancer: What have we learned from the 21-gene recurrence score assay?

Most invasive breast cancers express hormone receptors (HR) and typically have a favorable prognosis following endocrine therapy. Patients at a higher risk of recurrence can be identified by multigene prognostic classifiers such as the 21-gene recurrence score (RS) assay, 70-gene prognostic signature, PAM-50, 12-gene molecular score, and others. The 21-gene RS assay (Oncotype Dx™, Genomic Health, Redwood City, CA) has level I clinical evidence and is the most widely used multigene assay in North America. The RS assay is based on reverse transcriptase polymerase chain reaction that can be performed on the RNA isolated from formalin-fixed paraffin-embedded tissue. It evaluates the expression of 16 cancer-related genes developed based on a multi-step approach. Due to its ability to assess recurrence risk and predict potential benefit from chemotherapy, the assay is recommended for patients with node-negative, HR-positive, and human epidermal growth factor receptor 2 (HER2)-negative breast cancer by the American Society of Clinical Oncology, National Comprehensive Cancer Network clinical practice guidelines in oncology, European Society for Medical Oncology clinical practice guidelines, and St. Gallen consensus panel guidelines. The RS assay has also been incorporated in the prognostic stage groups in the 8th edition of the American Joint Commission of Cancer staging manual in order to provide essential genomic information for optimal treatment decisions. This review will focus on the utility of the RS assay in HR-positive and HER2-negative breast cancer patients, including risk of distant and locoregional recurrence in node-negative and node-positive tumors, association with radiotherapy, special subtypes of breast cancer, practical issues related to selecting tumors for testing, and overview of the recently published TailorX (Trial Assigning IndividuaLized Options for treatment [Rx]) results.