Comprehensive genomic profiling of salivary gland carcinoma: Analysis of the Center for Cancer Genomics and Advanced Therapeutics database in Japan

Comprehensive information on genetic alterations in salivary gland cancer (SGC) is limited. This study aimed to elucidate the genetic and clinical characteristics of patients with SGC using the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database, a Japanese national genomic database. We analyzed data of 776 patients with SGC registered in the C-CAT database between June 1, 2019, and June 30, 2023. Adenoid cystic carcinoma was the most common histologic type, followed by salivary duct carcinoma (SDC) and adenocarcinoma not otherwise specified. Genetic data of 681 patients receiving FoundationOne (R) CDx were analyzed. We identified specific features of the combination of TP53 and CDKN2A alterations among the histological types. Specific LYN amplification was mainly detected in carcinoma ex pleomorphic adenoma and myoepithelial carcinoma. For SDC, the frequency of ERBB2 and BRAF alterations were higher in cases with metastatic lesions than in those with primary lesions. Although 28.6% patients were offered recommended treatment options, only 6.8% received the recommended treatments. This study highlights the differences in genetic alterations among the histological types of SGC, with comprehensive genomic profiling tests revealing lower drug accessibility. These findings could contribute to the development of personalized treatment for patients with SGC. Salivary gland cancers (SGCs) are classified histologically into more than 20 types. This vast heterogeneity has slowed progress toward a standard treatment regimen for SGC. Here, the authors analyzed data from the Center for Cancer Genomics and Advanced Therapeutics database in Japan to better understand SGC characteristics and their impact on treatment. Genetic features, such as LYN amplification, were associated with specific histological types, while increased frequency of ERBB2 and BRAF alterations was observed in metastatic lesions. Whether patients received treatment was influenced by histological type. The findings highlight features in SGC that can be leveraged for personalized treatment. image