As reported in the Journal of Clinical Oncology, Bidard et al developed a model that may identify a subgroup of patients with clinical high-risk estrogen receptor (ER)-positive/HER2-negative early breast cancer who might derive no additional distant recurrence benefit from escalation of adjuvant therapy (eg, with CDK4/6 inhibition) beyond standard adjuvant therapy.
Study Details
In the study, investigators developed a model integrating 4 clinicopathologic variables and 10 features from digitized hematoxylin-and-eosin–stained resection slides capturing tumor architecture, microenvironment, and proliferation. The model was tested by retrospective application to treatment groups in the CANTO and UNIRAD trials who received standard, but not escalated, adjuvant therapy. The model characterized patients as low-risk or not–low-risk for distant recurrence.
Key Findings
Among 402 patients in the CANTO cohort, 85 (21.1%) were identified as low-risk. At 9 years of follow-up, 94.7% of the low-risk patients remained free from distant recurrence and death from breast cancer, compared with 77.4% of the not–low-risk patients.
Among 231 patients in the UNIRAD cohort, 38 (16.5%) were identified as low-risk. At 9 years of follow-up, 97.3% of the low-risk patients remained free from distant recurrence and death from breast cancer, compared with 74.9% of the not–low-risk patients.
For the combined cohorts, 95.4% of the low-risk patients remained free of distant recurrence and death from breast cancer at 9 years, compared with 76.8% of the not–low-risk group. Compared with the not–low-risk group, the low-risk group had significantly better distant recurrence-free interval (hazard ratio [HR] = 0.21, 95% confidence interval [CI] = 0.09–0.52, P < .001), invasive disease–free survival (HR = 0.31, 95% CI = 0.16–0.60, P < .001), and overall survival (HR = 0.35, 95% CI = 0.13–0.97, P = .044).
Multivariate analyses showed that the model provided predictive information beyond clinicopathologic variables.
The investigators concluded: “The assay demonstrated robust performance in identifying a core group of patients with high-risk [estrogen receptor–positive/HER2-negative] breast cancer for whom additional adjuvant treatment may be futile.”
Marvin Lerousseau, PhD, of Spotlight Medical, Paris, France, is the corresponding author for the Journal of Clinical Oncology article.
Disclosure: The study was supported by Spotlight Medical. For full disclosures of all study authors, visit ascopubs.org.
