Correlation between Ki67 and Histological Grade in Breast Cancer Patients Treated with Preoperative Chemotherapy

Abstract

Background and Aim: Breast cancer (BC) is a heterogeneous disease and cell proliferation markers may help to identify subtypes of clinical interest. We here analyzed the correlation between cell proliferation determined by Ki67 and HG in BC patients undergoing preoperative chemotherapy (PCT). Materials and Methods: We obtained clinical/pathological data from patients with invasive BC treated at our institution from 1999 until 2012. Expression of estrogen receptor (ER), progesterone receptor (PR), epidermal growth factor receptor type 2 (HER2) and Ki67 were determined by immuno-histochemistry (IHC). Clinicopathological subtypes were defined as: Luminal A, ER and/or PR positive, HER2 negative, HG 1 or 2; Luminal B, ER and/or PR positive, HER2 negative or positive and/or HG 3; triple negative (TN), ER, PR and HER2 negative independent of HG; HER2 positive, ER, PR negative and HER2 positive, independent of HG. By using Ki67, a value of 14% separated Luminal A and B tumors, independently of the histological grade. We analyzed correlations between Ki67 and HG, to define BC subtypes and their predictive value for response to PCT. Results: 1,560 BC patients were treated in the period, 147 receiving PCT (9.5%). Some 57 had sufficient clinicopathological information to be included in the study. Median age was 52 years (26-72), with 87.7% invasive ductal carcinomas (n=50). We performed IHC for Ki67 in 40 core biopsies and 50 surgical biopsies, 37 paired samples with Ki67 before and after chemotherapy being available. There was no significant correlation between Ki67 and HG (p=0.237), both categorizing patients into different subtypes. In most cases Ki67 decreased after PCT (65.8%). Only 3 patients had pathologic complete response (cPR). Conclusions: In our experience we did not find associations between Ki67 and HG. Determination of clinicopathological luminal subtypes differs by using Ki67 or HG.

Conserved genes and pathways in primary human fibroblast strains undergoing replicative and radiation induced senescence

“…GRN proteins play a role in wound healing [ 86 ]. Ki67 is a marker for proliferation [ 35 , 87 ]. CTSK is normally stimulated by inflammatory cytokines released after tissue injury [ 88 ].…”

Predicting the response to neoadjuvant therapy for early-stage breast cancer: tumor-, blood-, and imaging-related biomarkers

“…22 In an NAT cohort study, histological grade was not found to be significantly correlated with Ki-67, even though, in approximately two-thirds of the cases, Ki-67 decreased after NAT. 23 Some of these pathological features have proven to be predictive, eg, ER and HER2. However, their predictive response to NAT warrants further clinical validation.…”

Prognostic parameters of luminal A and luminal B intrinsic breast cancer subtypes of Pakistani patients

“…Ki67 index reflects the proportion of the proliferation genes/cells and thus employed to subtype luminal tumors. Therefore, Ki67 index is also utilized to tailor the therapy for the patient as in some cases chemotherapy or endocrine therapy alone is inadequate [ 5 ]. Although exact cutoffs for ki67 and PR were not defined in St. Gallen International Expert Consensus, however, some proposals were given, stating that a cutoff value of < 14% ki67 can be used to define luminal cancers in the absence of HER2neu expression based on single reference laboratory [ 6 ].…”