With the promise and potential of clinical next-generation sequencing for tumor and germline testing to impact treatment and outcomes of patients with cancer, there are also risks of oversimplification, misinterpretation, and missed opportunities. These issues risk limiting clinical benefit and, at worst, perpetuating false conclusions that could lead to inappropriate treatment selection, avoidable toxicity, and harm to patients. This report presents 5 case studies illustrating challenges and opportunities in clinical next-generation sequencing interpretation and clinical application in solid tumor oncologic care. First is a case that dissects the origin of an ATM mutation as originating from a hematopoietic clone rather than the tumor. Second is a case illustrating the potential for tumor sequencing to suggest germline variants associated with a hereditary cancer syndrome. Third are 2 cases showing the potential for variant reclassification of a germline variant of uncertain significance when considered alongside family history and tumor sequencing results. Finally, we describe a case illustrating challenges with using microsatellite instability for predicting tumor response to immune checkpoint inhibitors. The common theme of the case studies is the importance of examining clinical context alongside expert review and interpretation, which together highlight an expanding role for contextual examination and multidisciplinary expert review through molecular tumor boards.
Alexandra O. Sokolova, Brian H. Shirts, Eric Q. Konnick, Ginger J. Tsai, Bernardo H.L. Goulart, Bruce Montgomery, Colin C. Pritchard, Evan Y. Yu and Heather H. Cheng
C. Anthony Blau, Arturo B. Ramirez, Sibel Blau, Colin C. Pritchard, Michael O. Dorschner, Stephen C. Schmechel, Timothy J. Martins, Elisabeth M. Mahen, Kimberly A. Burton, Vitalina M. Komashko, Amie J. Radenbaugh, Katy Dougherty, Anju Thomas, Christopher P. Miller, James Annis, Jonathan R. Fromm, Chaozhong Song, Elizabeth Chang, Kellie Howard, Sharon Austin, Rodney A. Schmidt, Michael L. Linenberger, Pamela S. Becker, Francis M. Senecal, Brigham H. Mecham, Su-In Lee, Anup Madan, Roy Ronen, Janusz Dutkowski, Shelly Heimfeld, Brent L. Wood, Jackie L. Stilwell, Eric P. Kaldjian, David Haussler and Jingchun Zhu
Accelerating cancer research is expected to require new types of clinical trials. This report describes the Intensive Trial of OMics in Cancer (ITOMIC) and a participant with triple-negative breast cancer metastatic to bone, who had markedly elevated circulating tumor cells (CTCs) that were monitored 48 times over 9 months. A total of 32 researchers from 14 institutions were engaged in the patient's evaluation; 20 researchers had no prior involvement in patient care and 18 were recruited specifically for this patient. Whole-exome sequencing of 3 bone marrow samples demonstrated a novel ROS1 variant that was estimated to be present in most or all tumor cells. After an initial response to cisplatin, a hypothesis of crizotinib sensitivity was disproven. Leukapheresis followed by partial CTC enrichment allowed for the development of a differential high-throughput drug screen and demonstrated sensitivity to investigational BH3-mimetic inhibitors of BCL-2 that could not be tested in the patient because requests to the pharmaceutical sponsors were denied. The number and size of CTC clusters correlated with clinical status and eventually death. Focusing the expertise of a distributed network of investigators on an intensively monitored patient with cancer can generate high-resolution views of the natural history of cancer and suggest new opportunities for therapy. Optimization requires access to investigational drugs.