Breast Cancer Experience of the Molecular Tumor Board at the University of California, San Diego Moores Cancer Center.

PURPOSE Multiplex genomic tests are enabling oncologists to interrogate the DNA of their patients. However, few oncologists are proficient with respect to the implications of complex molecular diagnostics. We initiated a Molecular Tumor Board that focused on individual patients with advanced cancer whose tumors underwent genomic profiling, and here report our experience with breast cancer. METHODS A multidisciplinary team that included physicians, scientists, geneticists, and bioinformatics/pathway specialists attended. All molecular tests were performed in a Clinical Laboratory Improvement Amendments environment (next-generation sequencing, 182 or 236 genes). RESULTS Forty of 43 patients (93%; mean age, 59 years) had at least one theoretically actionable aberration (mean, 4.79 anomalies/patient). Median time from ordering to report was 27 days (median of approximately 11 days for specimen acquisition and approximately 14 days for diagnostic processing). Even if we considered distinct abnormalities in a gene as the same, there were only two patients with an identical molecular profile. Seventy-three genes (206 abnormalities; 119 distinct) were aberrant. Seventeen of the 43 patients (40%; median, seven previous therapies in the metastatic setting) were treated in a manner consistent with Molecular Tumor Board discussions; seven (16% of 43, or 41% of 17) achieved stable disease for 6 or more months (n = 2) or partial remission (n = 5). Lack of access to targeted medication was the most common reason that patients could not be treated. CONCLUSION Multidisciplinary molecular tumor boards may help to optimize the management of patients with advanced, heavily pretreated breast cancer who have undergone genomic testing. Facilitating availability of appropriately targeted drugs and clinical trials is needed.