A new study published online by JAMA Oncology examined the prevalence and significance of estrogen receptor mutations in patients with metastatic breast cancer.1
The activation of the estrogen receptor is a feature of most breast cancers in which estrogen receptor expression is detected. An aromatase inhibitor for estrogen-deprivation therapy is an effective therapy for those tumors and reduces cancer morbidity and mortality. Outcomes for patients with estrogen receptor–positive metastatic breast cancer who are treated with aromatase inhibitors vary considerably, with relapse for some patients within months and after many years for others.
Sarat Chandarlapaty, MD, PhD
Sarat Chandarlapaty, MD, PhD, of Memorial Sloan Kettering Cancer Center, New York, and coauthors conducted a secondary analysis of cell-free DNA from 541 patients enrolled in a clinical trial to determine the prevalence of mutations and whether they were associated with worse outcomes.
The authors reported 29% of patients had a mutation in the estrogen receptor, and the mutation was associated with shorter overall survival, according to the report.
The authors concluded: “Mutations in the estrogen receptor are common in patients with metastatic breast cancer who were previously treated with an aromatase inhibitor and are associated with worse outcomes.” ■
Disclosure: The authors reported no potential conflicts of interest.