Treatment costs for patients with metastatic breast cancer are substantially altered years after diagnosis and by receptor subtype, study authors reported at the 2022 ASCO Annual Meeting. They also found annual costs increased over time and were greatest for patients with hormone receptor positive, human epidermal growth factor receptor 2 negative (HR+/HER2-) and lowest for patients with triple negative (TNBC).

With changes in treatment costs and clinical practice changing in the past decade in the United States due to significant advances in treating metastatic breast cancer, researchers sought to determine treatment patterns in patients with metastatic breast cancer by year after diagnosis and subtype as well as connected costs from societal and payer perspectives.

Data was extracted from the nationwide Flatiron Health electronic health record-derived deidentified database focused on January 2011 to May 2021.

Excluded cases included those with male patients, who had no treatment data, received therapies not used in metastatic breast cancer, contained no structured data within 90 days of diagnosis, had <6 months of follow up, participated in clinical trials, had non-breast invasive cancers, or had no data on HER2 and HR.

Eligible patients were classified into 4 subgroups: HER2-HR+, HER2+HR+, HER2+HR-, and TNBC. Researchers calculated supportive and anticancer drug costs at the patient level and mean costs by year after diagnosis for each subgroup.

There were 15,215 patients who met the study criteria (64.41% non-Hispanic White, 66.85% HER2-HR+, 18.30% HER2+HR+, 5.27% HER2+HR-, 9.58% TNBC).

Associated Medicare cost and annual wholesale price estimates were $334,812 for HER2+HR+, $284,609 for HER2+HR-, $104,774 for HER2-HR+, and $54,355 for TNBC subgroups.

“We observed an increase in annual costs between years 2011-2021 in most subgroups,” wrote researchers. “This increase was most substantial for HER2-HR+ patients. From 2011 to 2019 (most recent complete year 1 data is for patients diagnosed in 2019), annual Medicare treatment costs in year 1 increased from $12,986 to $80,563 for HER2-HR+, $99,997 to $156,712 for HER2+HR+, and $31,397 to $53,775 for TNBC.”

Costs of treating (HER2+HR-) did not increase in year 1, but in year 2 an increase was observed.

Reference:
Chehayeb RJ, Hood A, Schellhorn Mougalian S, et al. Treatment patterns and medical costs of metastatic breast cancer care in the United States. J Clin Oncol. 2022;40(suppl 16): abstract e18834. doi:10.1200/jco.2022.40.16_suppl.e18834