OBJECTIVES

In hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) advanced breast cancer (ABC) patients, current treatment guidelines recommend three consecutive endocrine therapy (ET) regimens. This study was conducted to identify the real-world treatment patterns and to provide epidemiological data related to HR+, HER2- ABC in Korea.

METHODS

A retrospective observational study between 4/1/2013 and 8/31/2017 was conducted using Korean nationwide health insurance claims data. HR+, HER2- ABC patients were identified using ICD-10 codes (C50) and claims history (at least one ET, no HER2 targeted therapy, and a second and subsequent line of palliative therapy according to the Korean reimbursement guideline). Palliative treatments in the second and subsequent lines include Everolimus and Exemestane combination (EE), Gemcitabine and Albumin-bounded Paclitaxel, and Eribulin. Treatment patterns and its associated patient characteristics were assessed using descriptive statistics.

RESULTS

Of those 2,208 HR+, HER2- ABC patients, 1,111 (50.3%), 685 (31.0%), and 412 (18.7%) received EE, chemotherapy (CT) including Gemcitabine and Albumin-bounded Paclitaxel, and Eribulin, respectively. Patients who received Eribulin had higher mean Charlson Comorbidity Index (CCI) score, and patients who received CT or Eribulin used more analgesics, and had higher mortality rate as compared to those who received EE. While 13.5% of patients treated with EE received CT in the previous line, 86.1% of them were followed by CT. Overall, patients treated with CT received higher proportion of prior and subsequent line of CT than ET. Although monotherapy was more frequently used than combination therapy in prior CT regimens across all treatment groups, considerable proportions used combination CT (29.9%, 36.1%, 33.5%).

CONCLUSIONS

This study provides real-world evidence on the treatment pattern among HR+, HER2- ABC patients showing the variation between the real world practice and the treatment guidelines. New treatment options should be introduced to minimize current limitation with clinical management in Korea.