First-line regimens with endocrine therapy show benefits in breast cancer

First-line regimens with endocrine therapy (ET) may be associated with benefits among patients with human epidermal growth factor receptor 2-positive (ERBB2-positive [formerly HER2-positive]) metastatic breast cancer (MBC), according to a study published online Dec. 15 in JAMA Network Open.

Marcela Carausu, M.D., from Institut Curie in Saint-Cloud, France, and colleagues evaluated the association of hormone receptor status and first-line inclusion of ET with outcomes among patients with ERBB2-positive MBC. The analysis used clinical data from the French clinical Epidemiological Strategy and Medical Economics cohort of 4,145 patients who started treatment between 2008 and 2017 with follow-up through June 18, 2020.

The researchers observed no significant difference in overall or progression-free survival for 1,520 patients treated with ERBB2-targeted therapy with chemotherapy and with or without ET versus 203 patients receiving ERBB2-targeted therapy with ET. Findings were seen regardless of type of ERBB2-targeted therapy (trastuzumab or trastuzumab with pertuzumab). In propensity-matched patients, results were similar. Among patients with ERBB2-targeted therapy with chemotherapy, those with maintenance ET had significantly better progression-free (hazard ratio, 0.70) and overall survival (hazard ratio, 0.47).

"Our findings suggest that ET-containing regimens may be associated with benefits for a subgroup of patients, suggesting that results from randomized clinical trials investigating a more personalized approach for these patients may be relevant and necessary," the authors write.

Several authors disclosed financial ties to the pharmaceutical industry.