Posted: Tuesday, September 13, 2022
Abirami Sivapiragasam, MD, of Upstate University Hospital, Syracuse, New York, and colleagues used next-generation sequencing to try to determine which molecular targets may play a crucial role in managing advanced salivary gland carcinomas. Presented during the European Society for Medical Oncology (ESMO) Congress 2022 (Abstract 660MO), the results of their study suggest that BRAF genomic alterations were common in ductal cancers and adenoid cystic carcinoma, whereas targets such as NTRK had a low incidence. In addition, they noted that both immunotherapy and targeted therapy appear to be responsible for the increased precision of treatment in this patient population.
The investigators extracted DNA from the tissues of 1,666 patients with advanced salivary gland carcinoma. Comprehensive genomic profiling was performed to identify base deletions, insertions, copy number changes, rearrangements, gene fusions, and substitutions. Additionally, tumor mutation burden was calculated up to 1.25 Mb.
The most common subtype was adenoid cystic carcinoma, accounting for 28.3% of the patient population. Clinically relevant genetic alterations of CDKN2A and CDKN2B were common in both acinic cell carcinoma (59% and 37.4%) and mucoepidermoid carcinoma (52.5% and 30.5%). Additionally, alterations of PIK3CA appeared to be common in ductal carcinoma (32.6%) and high-grade carcinoma that was not otherwise specified (21.3%)—raising the question of whether agents such as alpelisib may be appropriate.
Of note, short variants and amplification of ERBB2 were found in both carcinoma ex pleomorphic adenoma (17.6% and 9.8%) and ductal carcinoma (16.3% and 3.6%), suggesting that therapies targeting ERBB2 may play a significant role in disease management. Although less frequent, genetic alterations in BRAF were identified in ductal carcinoma (5.6%) and acinic cell carcinoma (3.6%).
Furthermore, there appeared to be a low incidence of targets EGFR, NTRK, BRCA, RET, and FGFR. A tumor mutation burden higher than 10 was observed in high-grade carcinoma not otherwise specified (18.3%) and mucoepidermoid carcinoma (16.9%). Furthermore, PD-L1 appeared to be elevated in high-grade carcinoma not otherwise specified (8.9%), implying this subtype may respond to immunotherapy.
Disclosure: For full disclosures of the study authors, visit cslide.ctimeetingtech.com.