Guideline concordance of recurrence risk assessment for early breast cancer in a county-level setting in China.

Abstract

e23263 Background: Guideline-centric risk-based decision-making is crucial for the treatment of HR+HER2- and HER2+ early breast cancer (eBC). However, the consistency of recurrence risk assessment (RA) between real-life clinical practice and guidelines in China has not been thoroughly investigated. As part of the interim analysis of CHASE001 (NCT05544123), we explored the guideline concordance of RA for HR+HER2- and HER2+ eBC in a county-level setting in China. Methods: Cohorts of HR+HER2- and HER2+ eBC patients (pts) from a county-level observational study (CHASE001) were included in this analysis. Clinical recurrence risk were collected for each patient. Descriptive statistics reported the proportion of pts classified into each risk level under real-life assessment by healthcare professionals (HCPs) (H-low/intermediate/high) and guideline-consistent assessment (G-low/intermediate/high). To investigate the factors associated with lower consistency, univariate (UVA) and multivariate logistic regression analysis (MVA) were performed. Results: 1254 HR+HER2- and 841 HER2+ eBC pts from 26 county-level hospitals were included in this analysis. A comparison between recurrence risk under HCPs assessment (HA) and guideline-consistent assessment (GA) revealed divergence. In HR+HER2- cohort, the proportions of pts classified as low, intermediate (int), and high clinical risk for recurrence under HA/GA were 27.2%/2.0%, 48.0%/57.4%, 24.8%/40.6%, respectively. Notably, 36.8% of pts classified as G-int were categorized as H-low, while 47.5% G-high pts were classified as H-int/low. On UVA and MVA, pT1 stage, histological grade 1 and Ki67 < 20% were associated with G-int/H-low; whereas lymphovascular invasion and pN1 were associated with G-high/H-lower. Among 562 G-int/high premenopausal pts, 280 (49.8%) achieved ovarian function suppression (OFS) and the OFS rates were 46.1% in G-int and 55.3% in G-high pts. In HER2+ cohort, the proportions of pts classified as low, int and high risk under HA/GA were 17.2%/0%, 48.2%/51.2% and 34.6%/48.8%. In pts with pN0, 17.2% were classified as H-low and 12% as H-high. In pts with positive lymph nodes (LN+), 11% were classified as H-low and 31% as H-int. Dual anti-HER2 target therapy was administered in 72% of pts with LN+. In both cohorts, HCPs who were medical oncologists had higher consistency with guideline for high-risk evaluation compared to surgical oncologists, whereas surgical oncologists showed higher consistency for int-risk evaluation compared to medical oncologists. Conclusions: This analysis highlights differences in clinical practice between county-level HCPs and guideline recommendations, revealing a significant underestimation of breast cancer recurrence risk. Further efforts should be made to enhance guideline adherence and promote guideline-centric clinical risk-based decision-making at county-level hospitals. Clinical trial information: NCT05544123 .