Immune checkpoint inhibitors and molecular-targeted therapies have dominated recent cancer treatment. However, these treatments face challenges, such as primary and acquired resistance, indicating that not all patients benefit from them. Therefore, the search for new molecular targets is crucial. In addition, immune checkpoint inhibitors have exhibited racial differences in their effectiveness for certain neoplasms. Hence, understanding the genomic landscape of cancers in various racial groups is important. In Japan, health insurance has covered comprehensive genomic profiling since 2019, and the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) has accumulated genetic abnormalities along with clinical data of patients with various cancers. These data are crucial for advancing cancer research and drug development. This review discusses the genetic abnormalities of the major skin malignancies including melanoma, cutaneous squamous cell carcinoma (cSCC), and extramammary Paget's disease (EMPD), and proposes potential treatment strategies by comparing C-CAT data analysis with other genetic studies. The C-CAT data have emphasized unique genetic alterations in tumors of the Japanese population, particularly racial differences in tumor mutational burden in cutaneous melanoma and cSCC, indicating the importance of personalized treatment strategies that consider racial differences.
Keywords: Extramammary Paget’s disease; Immune checkpoint inhibitors; Melanoma; Molecular-targeted therapy; Mutation; Squamous cell carcinoma.
© 2025. The Author(s) under exclusive licence to Japan Society of Clinical Oncology.