Clinical Actionability of Molecular Targets in Multi-Ethnic Breast Cancer Patients: A Retrospective Single-Institutional Study

In this study, a total of 784 clinically actionable mutations were reported for 1010 patients with genomic sequencing. Of these, 96/1010 (10%) patients had at least one actionable mutation in homologous recombination repair genes (BRCA1, BRCA2, PALB2) and 36/96 (37.5%) patients received PARP inhibitors (33 olaparib and three talazoparib). In addition, 381/1010 (38%) patients had at least one clinically actionable PIK3CA mutation, and 84/381 (22%) received alpelisib. Additionally, 544/1010 (54%) of patients had either AKT1 (41/1010), PIK3CA (381/1010), or PTEN (122/1010) alterations that were FDA approved in November 2023 for capivasertib in the treatment of HR+HER2- metastatic BC (MBC) patients. Furthermore, 144/1010 (14%) patients in this study had at least one ESR1 mutation, a clinically actionable mutation that was FDA approved in January 2023 for elacestrant in the treatment of ER+HER2- MBC patients (44% detected by liquid biopsy). Future studies are needed to determine the efficacy of elacestrant and capivasertib for patients with these mutations, and to tailor strategies for optimal patient quality of life and cancer outcome.