Publication

Ki67 as Proliferative Marker in Patients with Early Breast Cancer and Its Association with Clinicopathological Factors

Journal Paper/Review - Sep 14, 2021

Units
PubMed
Doi

Citation
De Gregorio A, Friedl T, Hering E, Widschwendter P, De Gregorio N, Bekes I, Janni W, Davut D, Huober J. Ki67 as Proliferative Marker in Patients with Early Breast Cancer and Its Association with Clinicopathological Factors. Oncology 2021; 99:780-789.
Type
Journal Paper/Review (English)
Journal
Oncology 2021; 99
Publication Date
Sep 14, 2021
Issn Electronic
1423-0232
Pages
780-789
Brief description/objective

INTRODUCTION
Ki67 as a proliferative marker has prognostic and therapeutic relevance in early breast cancer (EBC). However, standard cutoffs for distinguishing low and high Ki67 do not exist.

MATERIAL AND METHODS
Data from all patients treated at the University Hospital Ulm for EBC between January 2013 and December 2015 with documented results for internal Ki67 assessment of the primary (n = 917) tumor were retrospectively analyzed evaluating the associations between Ki67 and other clinicopathological factors.

RESULTS
595 (64.9%) patients had a Ki67 <20% and 322 (35.1%) a Ki67 ≥20%. The median Ki67 was 10% (range 1-90%). Median Ki67 values according to the hormone receptor (HR)/ human epidermal growth factor receptor 2 (HER2) subtypes were 10% for HR-positive/HER2 negative (HR+/HER2-) disease (n = 717), 20% for HR+/HER2+ (n = 76), 30% for HR-/HER2+ (n = 45), and 60% for HR-/HER2- (n = 75). 75.2% or 89.3% of all patients with HER2-positive or triple-negative disease had a Ki67 ≥20%, respectively. Using a multivariable logistic regression with Ki67 (<20% vs. ≥20%) as binary dependent variable, younger age, positive nodal status, higher grading, histological nonspecific type carcinoma, negative HR status, and positive HER2 status were shown to be significantly associated with a higher proliferative index (Ki67 ≥20%).

CONCLUSION
This analysis described Ki67 in different subtypes in EBC and its association with clinicopathological factors. According to more aggressive tumor biology, the respective subgroups also showed higher median Ki67 levels. However, definition of low and high proliferation index itself is difficult. It is essential to interpret Ki67 indices carefully with regard to the own institutional values and other clinicopathological factors.