20P - Real-world treatment of HER2+ and HR+/HER2- early breast cancer in county areas of China

Background

In China, new breast cancer (BC) patients (pts) in county regions (including rural areas) account for more than 40% of all BC cases each year. No studies have reported the disease characteristics and treatment patterns of BC pts in China counties. This study aimed to explore the treatment patterns of BC pts in county-level hospitals in China.

Methods

CHASE001 was an observational, multicenter study assessing real-world treatment patterns among pts with HER2+ or HR+/HER2- BC conducted at 26 sites in county areas of China, including four cohorts (HER2+ early BC (eBC), HR+/HER2- eBC, HER2+ advanced BC (aBC), and HR+/HER2- aBC). The primary endpoint was treatment patterns within each cohort. The interim results for HER2+ eBC and HR+/HER2- eBC are described here.

Results

628 pts were included (302 in HER2+ eBC and 326 in HR+/HER2- eBC cohort): for HER2+ and HR+/HER2- cohort respectively, median age, 53/51 years; clinical T2, 41.39%/37.73%; clinical N0, 41.72%/45.40%. Of 584 pts who underwent breast cancer surgery, only 10.53% (30/285) received breast-conserving surgery (BCS) in HER2+ and 12.71% (38/299) in HR+/HER2- cohort. Notably, the proportions of adjuvant radiotherapy (RT) following BCS were 46.67% (14/30) in HER2+ and 47.37% (18/38) in HR+/HER2- cohort. In HER2+ cohort, 20.20% (61/302) received neoadjuvant therapy (NAT) while 94.70% (286/302) received adjuvant therapy. 81.97% (50/61) of NAT were HER2 targeted regimens, of which 84.00% (42/50) received dual anti-HER2 target therapy (trastuzumab/pertuzumab). 80.77% (231/286) of adjuvant therapies were HER2 targeted regimens, of which 53.68% (124/231) were dual-targeted. Of pts with positive lymph nodes who received HER2 targeted adjuvant therapy, 75.90% applied dual anti-HER2 target therapy. In HR+/HER2- cohort, 13.50% (44/326) received NAT while 92.02% (300/326) received adjuvant therapy. The most common neoadjuvant and adjuvant chemotherapy regimens were both AC-T (41.67% and 51.79%, respectively).

Conclusions

This analysis showed unsatisfactory adherence to guidelines for BCS, RT, and NAT, but higher adherence for adjuvant anti-HER2 therapy. Further action was needed to ensure that patients in Chinese county had access to high quality and guideline centric care.

Clinical trial identification

NCT05544123.

Editorial acknowledgement

Legal entity responsible for the study

P. Lu.

Funding

AstraZeneca.

Disclosure

All authors have declared no conflicts of interest.