Biomarkers, Tumor / metabolism ; Biopsy ; Breast Neoplasms* / diagnosis ; Breast Neoplasms* / metabolism ; Breast Neoplasms* / surgery ; Female ; Humans ; Ki-67 Antigen* / metabolism ; Postoperative Period ; Prognosis ; Receptor, ErbB-2 / metabolism ; Receptors, Estrogen / metabolism ; Receptors, Progesterone / metabolism
Keywords
Biopsy ; Breast cancer ; Ki-67 ; Prognosis ; Surgical specimen
Abstract
Purpose: This study aimed to identify the association between Ki-67 level and the prognosis of patients with breast cancer, regardless of the timing of Ki-67 testing (using preoperative biopsy vs. postoperative specimen).
Methods: A total of 4177 patients underwent surgery between January 2008 and December 2016. Immunohistochemical Ki-67 levels, using either preoperative (1673) or postoperative (2831) specimens, were divided into four groups using cutoff points of 10%, 15%, and 20%.
Results: Groups with higher-Ki-67 levels, in both the pre- and postoperative periods, showed significantly larger tumor size, higher grade, more frequent hormone receptor-negativity and human epidermal growth factor receptor 2 overexpression, and active adjuvant treatments than groups with lower-Ki-67 levels. High-Ki-67 levels were also significantly associated with poor survival, irrespective of the timing of specimen examination.
Conclusion: Despite the problems associated with Ki-67, Ki-67 level is an important independent prognostic factor, regardless of the timing of Ki-67 testing, i.e., preoperative or postoperative testing.