At the ASCO Annual Meeting in Chicago (June 1 to June 5), the Cancer Genetics Laboratory and the Whole Genome Laboratory at Baylor College of Medicine (BCM) will officially announce the clinical implementation of the Cancer Exome Sequencing test. This test is the result of a collaboration between genomic scientists, clinical laboratory scientists, geneticists and oncologists at BCM to provide reliable cancer genome-wide analyses that are carefully annotated and interpreted for clinical significance.
The Cancer Exome Sequencing test follows on the successful 2011 launch of germline exome sequencing for the evaluation of inherited disorders. The Cancer Exome Sequencing test focuses on somatically acquired genetic alterations in tumors and applies the power of next-generation sequencing technology to cancer genetics in a CAP/CLIA-approved setting with clinical interpretation of sequence information. This test is ordered by a physician and may be used when a patient’s oncology management would benefit from identifying genetic changes in the tumor that predict sensitivity or resistance to a variety of therapeutic regimens.
Cancer Exome Sequencing is poised to change the current paradigm of genetic testing for cancer patients by focusing on whole exome analysis of a patient’s tumor. The term exome refers to the portion of the human genome that contains the DNA sequence that directs protein synthesis. These functionally important regions of DNA are referred to as exons. The 22,000 known genes are comprised of approximately 180,000 exons and represent about 3% of the genome. Most errors in DNA sequence that lead to altered protein function in tumors are located in the exons, therefore, exome sequencing is an efficient method for tumor DNA sequence analysis to uncover genetic causes for tumor behavior.
The principle of the test is to sequence nucleotide by nucleotide, the human exome of normal tissue (generally blood) and a sample of tumor tissue to a depth of coverage necessary to determine sequence variations that are unique to the tumor (somatic mutations) with high sensitivity. Point mutations, insertions and deletions of the exome are potentially discoverable and could be considered important for cancer management depending on the defect and available evidence. These sequence variations are then categorized based on their role in defining a specific tumor property or tumor sensitivity to established and novel therapeutic approaches. This test will report all somatic mutations identified in the tumor genome and classifies them according to clinical utility based on careful evaluation of functional and clinical evidence in the medical/scientific literature and the availability of agents targeted to a specific gene or pathway. This test also reports the presence of inherited (germline) genetic variations in selected genes known to increase the risk for cancer (e.g. APC, TP53, and others).
Please join Baylor College of Medicine at the ASCO Annual Meeting (Booth #22082) for additional information on the Cancer Exome Sequencing test and to meet with BCM Medical Directors to further discuss this test and other services.
