BACKGROUND: Since June 2019, cancer genomic profiling (CGP) tests have been reimbursed by the National Health Insurance system in Japan, with restrictions for government-designated hospitals with a molecular tumor board composed of multidisciplinary specialists, known as an expert panel (EP). The standardization of EPs is a critical challenge for implementing precision oncology in the clinical setting. METHODS: Data on consecutive cases who underwent the CGP tests at 11 core hospitals between June 2019 and January 2020 were collected. We evaluated the proportions of cases that received genomically matched treatments, including investigational new drugs (INDs) based on CGP results, and/or for which genetic counseling was recommended. Two simulated cases were annotated by each EP. The annotated reports were then centrally assessed. RESULTS: Each EP mainly discussed the applicability to genomically matched treatments and the necessity of performing genetic counseling. A pre-review of the report by key members in each EP reportedly made the EP conference more interactive and efficient, and thereby saved time. A total of 747 cases underwent CGP tests, 28 cases (3.7%) received genomically matched treatment, and 17 cases (2.3%) were referred for genetic counseling. Annotated reports for the simulated cases varied across the EPs, particularly the number of recommended IND trials, which seemed to be associated with the actual number of participants in IND trials. CONCLUSIONS: This investigation provides reference data for the application of precision oncology in a clinical setting. Further investigations on the standardization of clinical annotations are warranted.