-Original-

Real-World Cancer Genomic Profiling at a Cooperative Hospital for Cancer Genomic Medicine in Japan

Ai Ikki^1,2, Masafumi Toyoshima^1,2, Tomoko Sahara¹, Maho Kuroda¹, Riku Watanabe², Ikuno Kawabata^1,2, Kay Uehara^1,3, Ryo Ohta³, Hiromichi Sonoda³, Shunji Suzuki² and Takeshi Yamada^1,3

¹Department of Genetic Medicine, Nippon Medical School Hospital, Tokyo, Japan
²Department of Obstetrics and Gynecology, Nippon Medical School Hospital, Tokyo, Japan
³Department of Gastroenterological Surgery, Nippon Medical School Hospital, Tokyo, Japan

Background: Comprehensive genomic profiling (CGP) tests have been covered by insurance in Japan since 2019, and their use in cancer genomic medicine (CGM) has expanded since then. Although extensive data are available from core hospitals, real-world data from community-based cooperative hospitals are limited.
Methods: Using data from 514 consecutive patients with advanced cancer who underwent CGP testing at our institution between June 2019 and March 2025, we investigated the proportion of cases receiving therapeutic recommendations, the rate of drug administration based on CGP test results, and the prevalence and management of presumed germline pathogenic variants (PGPVs).
Results: The most common cancer sites were the pancreas (18.7%), breast (16.9%), bowel (14.6%), lung (12.8%), and prostate (12.5%). An expert panel made up of molecular oncologists recommended 360 targeted therapies for 311 patients (60.5% of the total cohort). Ultimately, 80 patients (15.6%) received matched therapy, among whom 56 received medication under health insurance coverage, 22 through clinical trials, and 2 via the patient-requested medical treatment system. PGPVs were identified in 68 patients (13.2%). After discussion by the expert panel, confirmatory germline testing was offered to patients with PGPVs, and subsequent germline testing confirmed pathogenic variants in 18 patients (3.5% of the total cohort).
Conclusion: The proportion of patients who received targeted therapy at our cooperative hospital was comparable to proportions reported from core hospitals. However, disease progression was a significant barrier to accessing targeted therapies and genetic counseling. To maximize the benefits of CGM, the timing of CGP testing must be optimized and collaboration across departments and institutions must be strengthened.

J Nippon Med Sch 2026; 93: 145-152

Keywords
comprehensive genomic profiling, cancer genomic medicine, precision medicine, genetic counseling, incidental findings

Correspondence to
Masafumi Toyoshima
m-toyoshima@nms.ac.jp

Received, July 10, 2025
Accepted, December 3, 2025