Abstract 53P
Background
CHASE001 (NCT05544123) was a non-interventional, multicenter study exploring real-world treatment patterns among patients (pts) with HER2+ and HR+/HER2- breast cancer (BC) in county areas of China. Early BC treatment patterns were presented at ESMO Asia 2023. This analysis focuses on advanced BC (aBC) treatment selection in county areas.
Methods
The study was designed to enroll 2500 pts from 26 county hospitals in China. This analysis included newly diagnosed stage IV and recurrent metastatic BC pts with HER2+ and HR+/HER2. Descriptive statistics were used to report clinical and disease characteristics and treatment patterns. Chi-square tests and multivariate logistic regression analyses investigated factors associated with treatment selection.
Results
A total of 258 aBC pts were enrolled (147 in HR+/HER2- cohort and 111 in HER2+ cohort). The proportions of first-, second-, and third-line pts in the HR+HER2- and HER2+ cohorts were 59.4%/57.3%, 28.1%/27.1%, and 12.5%/15.6%, respectively. Among first-line pts, newly diagnosed stage IV and recurrent metastatic cases were 21.1%/78.9% in the HR+HER2- cohort and 41.8%/58.2% in the HER2+ cohort, respectively. Notably, compared to 63% of pts in the HR+ cohort, only 48.6% in the HER2+ cohort underwent re-biopsy of metastases. Among re-biopsied patients, 6.9% had HR loss, 4.0% had HR gain, 3.0% had HER2 loss, and 6.1% had HER2 gain. Metastasis sites included bone-only (16.1% in HR+/HER2-, 11.8% in HER2+), visceral (46.2% and 56.4%), and brain (4.9% and 10.0%). In the first-line setting, 53.5% of HR+HER2- pts received endocrine therapy (ET) while 46.5% received chemotherapy (CT). Only 32.9% of pts on ET were administered CDK4/6 inhibitors. In multivariate analysis, pts with bone-only metastases were associated with ET (OR 0.27, p=0.014), whereas premenopausal pts were more likely to receive CT (OR 1.78, p=0.07). In the HER2+ cohort, 89.9% of pts received HER2-targeted therapy as their first-line treatment, with 50.6% dual-targeted.
Conclusions
These findings reveal the current state and existing gaps in the diagnosis and treatment practices for advanced BC in county areas of China, indicating the importance of improving the medication accessibility of and promoting guideline-concordant care.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
AstraZeneca.
Disclosure
All authors have declared no conflicts of interest.