Circulating tumor cell count is a reliable biomarker for choosing between chemotherapy or endocrine therapy for patients with HER2-negative metastatic breast cancer, according to a recent study published in JAMA Oncology (2020 Nov 5. doi:10.1001/jamaoncol.2020.5660).
“The choice between chemotherapy and endocrine therapy as first-line treatment for [HER2-negative] metastatic breast cancer is usually based on the presence of clinical features associated with a poor prognosis,” wrote François-Clément Bidard, MD, PhD, Department of Medical Oncology, Institut Curie, Saint-Cloud, France, and colleagues.
“In this setting, a high circulating tumor cell count is a strong adverse prognostic factor for overall survival and progression-free survival (PFS),” they continued.
This randomized, open-label noninferiority phase 3 trial aimed to compare the efficacy of clinical driven treatment choice versus circulating tumor cell-driven treatment choice for the first-line treatment of metastatic breast cancer.
The primary end point was investigator-assessed PFS in the per-protocol population.
A total of 755 patients were included in the per-protocol population and randomized to clinician-driven first-line treatment choice (n = 377) or circulating tumor cell count–driven first-line treatment choice (n = 378). Chemotherapy was the treatment choice for 138 (37%) and 103 (27%) patients in each arm, respectively.
The median PFS was 15.5 months in the circulating tumor cell count-driven arm versus 13.9 months in the clinician-driven arm.
“This randomized clinical trial found that the [circulating tumor cell] count may be a reliable biomarker method for guiding the choice between chemotherapy and endocrine therapy as the first-line treatment in [HER2]-negative metastatic breast cancer,” concluded Dr Bidard and colleagues.—Marta Rybczynski
Barbara Jacoby is an award winning blogger that has contributed her writings to multiple online publications that have touched readers worldwide.