A retrospective, observational cohort study of treatment patterns and outcomes among patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative metastatic breast cancer in the United States following endocrine therapy.
To describe patient characteristics, treatment patterns and real-world survival in patients with hormone receptor-positive/human epidermal growth factor receptor 2-negative (HR+/HER2-) metastatic breast cancer (mBC) who received chemotherapy in the post-endocrine therapy (ET) setting where cytotoxic agents are the mainstay of treatment.
This retrospective, observational cohort study utilized data from the US nationwide Flatiron Health Research Database. Women aged ≥ 18 years with HR+/HER2 - mBC who received chemotherapy post-ET from January 1, 2015, to December 31, 2024, were included. Patient characteristics, treatment patterns, real-world overall survival (rwOS), and time to next treatment or death (rwTTNTD) were described post-ET.
5041 patients were included; median age was 63 years at mBC diagnosis. Most were non-Hispanic White (63%) and treated in the community setting (82%) and had Eastern Cooperative Oncology Group performance status 0-1 (59%) at the start of first-line treatment (1L) post-ET, recurrent mBC (68%), and ≥ 2 prior lines of ET-based treatment in the mBC setting (65%). Median time from mBC diagnosis to 1L post-ET was 19 months. Most patients (97%) received chemotherapy 1L post-ET. Median (95% CI) rwOS from start of 1L post-ET was 13.5 (13.0-14.1) months. 30% of patients who initiated 1L post-ET did not survive to the next treatment line; there was a decrease in rwOS with each subsequent treatment. Similar findings were observed for rwTTNTD.
These findings reinforce the high unmet need in patients with HR+/HER2 - mBC whose disease has become resistant to ET, highlighting the need for effective treatments in this setting.
This retrospective, observational cohort study utilized data from the US nationwide Flatiron Health Research Database. Women aged ≥ 18 years with HR+/HER2 - mBC who received chemotherapy post-ET from January 1, 2015, to December 31, 2024, were included. Patient characteristics, treatment patterns, real-world overall survival (rwOS), and time to next treatment or death (rwTTNTD) were described post-ET.
5041 patients were included; median age was 63 years at mBC diagnosis. Most were non-Hispanic White (63%) and treated in the community setting (82%) and had Eastern Cooperative Oncology Group performance status 0-1 (59%) at the start of first-line treatment (1L) post-ET, recurrent mBC (68%), and ≥ 2 prior lines of ET-based treatment in the mBC setting (65%). Median time from mBC diagnosis to 1L post-ET was 19 months. Most patients (97%) received chemotherapy 1L post-ET. Median (95% CI) rwOS from start of 1L post-ET was 13.5 (13.0-14.1) months. 30% of patients who initiated 1L post-ET did not survive to the next treatment line; there was a decrease in rwOS with each subsequent treatment. Similar findings were observed for rwTTNTD.
These findings reinforce the high unmet need in patients with HR+/HER2 - mBC whose disease has become resistant to ET, highlighting the need for effective treatments in this setting.
Authors
O'Shaughnessy O'Shaughnessy, Rehnquist Rehnquist, Sadetsky Sadetsky, Verret Verret, Cinar Cinar, Sjekloca Sjekloca, Nguyen Nguyen, Nanda Nanda, Sharma Sharma
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