What question did this study set out to answer?

February 5, 2026

Prognostic Significance of Different Ki-67 Cutoff Values Defined Luminal B HER2-Negative Breast Cancer

Key Points

This study aims to evaluate the prognostic significance of different Ki-67 cutoff values in luminal B HER2-negative breast cancer.
Analyzed data from 4940 patients with operable ER- or PR-positive and HER2-negative breast cancer.
Defined subtypes based on ER, PR, and HER2 status along with specified Ki-67 cutoff values.
Assessed disease-free survival (DFS), overall survival (OS), distant metastasis-free survival (DMFS), and breast cancer-specific survival (BCSS).
Luminal B (HER2-) tumors exhibited poor DFS irrespective of Ki-67 cutoff (14%, 20%, or 30%).
Subtypes with PR ≤ 20% and high Ki-67 index showed inferior OS, DMFS, and BCSS.
A Ki-67 cutoff value of 20% optimized the distinction of prognostic differences.

Abstract

Luminal B (HER2-) breast cancer is defined as ER- or PR-positive and HER2-negative meeting with PR ≤ 20%, or ER- or PR-positive and HER2-negative with high Ki-67 index, which has worse prognoses. The locally specified Ki-67 cutoff value has remained elusive in China. 4940 patients with ER- or PR-positive and HER2-negative operable breast cancer were recruited. The novel findings was that luminal B (HER2-) tumors showed poor DFS regardless of Ki-67 cutoff values (14, 20 or 30%), and luminal B (HER2-) subtype(PR ≤ 20% and high Ki-67 index) tumors showed inferior OS, DMFS, and BCSS. With Ki-67 cutoff value of 20%, it was optimized to distinguish prognostic differences.

KI fragen

Bookmark