11O Prospective Comparison of Risk Assessment Tools in Early Breast Cancer: Correlation Analysis from the Phase III Wsg-Plan B Trial

Abstract

ABSTRACT Background St. Gallen Consensus recommends use of Ki-67 and/or grade for definition of luminal A/B for indication of adj. chemotherapy (cht) in HR-pos. disease. Multi-gene based assays e.g. Recurrence Score® (RS) are used for decision support regarding adjuvant cht. Final WSG-PlanB trial correlation analysis of risk assessment tools focussing on correlation between central and local pathology assessment and RS is presented. Methods PlanB trial: 6xTC vs. 4xEC-4xDOC, locally HER2-negative BC; n = 2,448 for cht. RS was used as selection criterion for cht vs. endocrine therapy alone in HR + BC (if RS Results 3196 patients recruited, 2448 randomized. RS available in 2551 patients with HR+ tumors. RS distributed: 0-11 (18%), 12-25 (60%), >25 (22%). In 354 patients, cht was omitted based on low RS. Central grade was available for 3038 samples, IHC results are currently available in 1476 cases. Moderate significant correlations were found between RS and both central grade (Spearman’s coefficient rs = .313; p Discussion First prospective data show that high-risk status according to RS is predictive of high risk by uPA/PAI-1, high grade by central pathology, and luminal B subtype by Ki-67. There is substantial heterogeneity in risk assessment in the low and intermediate risk RS groups, where there are still patients considered high-risk according to uPA/PAI-1, Ki-67 or central grade. Follow-up of the WSG-Plan B trial will clarify the significance of these findings regarding patient outcomes. Disclosure S. Shak and C. Svedman: Employee of Genomic Health, Inc. All other authors have declared no conflicts of interest.