Survival Outcomes by TP53 Mutation Status in Metastatic Breast Cancer

PurposeTo determine the significant genomic alterations in patients with metastatic breast cancer (MBC) and survival outcomes in common genotypes.Patients and MethodsHigh-depth next-generation sequencing was performed for 202 genes in tumor and normal DNA from 257 patients with MBC, including 165 with estrogen receptor/progesterone receptor–positive and human epidermal growth factor receptor 2 (HER2 [hormone receptor positive (HR+)])–positive, 32 with HER2-positive, and 60 with triple-negative (estrogen receptor/progesterone receptor–negative and HER2-negative) disease. Kaplan-Meier survival analysis was performed in the discovery set, in patients with breast cancer analyzed in The Cancer Genome Atlas, and in a separate cohort of 98 patients with MBC who underwent clinical genomic testing.ResultsSignificantly mutated genes (SMGs) varied by histology and tumor subtype, but TP53 was an SMG in all three subtypes. The most SMGs in patients with HR+ cancer were PIK3CA (32%), TP53 (29%), GATA3 (15%), CDH1 (8%),...