Ki-67 as a Predictor of Response to Neoadjuvant Chemotherapy in Breast Cancer Patients

Abstract

PurposeThe objectives of this study were to assess the potential value of Ki-67 in predicting response to neoadjuvant chemotherapy in breast cancer patients and to suggest a reasonable cutoff value for classifying Ki-67 expression.MethodsThis study included 74 breast cancer patients who underwent surgery after anthracycline-based neoadjuvant chemotherapy between 2007 and 2012. We analyzed the clinical and immunohistochemical characteristics using core biopsy specimens obtained before neoadjuvant chemotherapy to determine their correlations with the response to chemotherapy.ResultsA clinical complete response was observed in 6 patients (8.1%); a clinical partial response, in 44 patients (59.5%); and clinical stable disease, in 24 patients (32.4%). A pathologic complete response (pCR) was observed in 10 patients (13.5%). In univariate analysis, estrogen receptor (ER) negativity (p=0.031), human epidermal growth factor receptor 2 (HER2) positivity (p=0.040), and high Ki-67 expression (p=0.036) were predictive factors for a pCR. In multivariate analysis, Ki-67 was the only independent predictor of a pCR (p=0.049). The analysis of Ki-67 values revealed that 25% was a reasonable cutoff value for predicting the response to chemotherapy. In subgroup analysis, a higher Ki-67 value (≥25%) was a significant predictive factor for the response to neoadjuvant chemotherapy, especially in ER-negative and HER2-positive breast cancer patients.ConclusionKi-67 expression in breast cancer tissue may be an effective factor for predicting the response to neoadjuvant chemotherapy. We suggest that a 25% level of Ki-67 expression is a reasonable cutoff value for predicting a response to chemotherapy. Moreover, Ki-67 is a useful predictive factor for pCR, especially in patients with ER-negative and HER2-positive breast cancer.

Proliferation rate and breast cancer subtype, but not ALDH1 expression, predict pathological response to neoadjuvant chemotherapy in locally advanced breast cancer

“…We did not find higher-grade tumours to respond better to NACT, contrary to publications on this issue [19]. Ki-67 index is considered an important independent factor predictive of NACT response, tumours with a higher proliferative index showing a significantly better response at a cutoff value of 20-25 % [18][19][20][21]. We found tumours with a proliferative index of 40 % or higher respond better to chemotherapy, which is higher than has been published, possibly due to particularities of our patient cohort.…”

The Neutrophil to Lymphocyte Ratio has a High Negative Predictive Value for Pathologic Complete Response in Locally Advanced Breast Cancer Patients Receiving Neoadjuvant Chemotherapy

“…pCR to NACT was lower in invasive lobular carcinoma compared with invasive ductal carcinoma (Cocquyt et al, 2003, Cristofanilli et al, 2005. Higher Ki-67 expression is associated with higher pCR rates (Kim et al, 2014). Smaller size tumors were also significant predictors of pCR (Bonadonna et al, 1990).…”

Predictors of Pathological Complete Response in Women with Clinical Complete Response to Neoadjuvant Chemotherapy in Breast Carcinoma

“…Probably, the carcinoma with a higher rate of tumoral replication has a greater sensitivity to chemotherapy with a high probability of having cCR [20,29,48]. No predictor of cCR in axilla was identified probably because of the low specificity and sensitivity of clinical methods for lymph nodes evaluation [35,39,40,52].…”

“…The ER expression was classified by Allred scoring into negative, low (2-6) and high (7-8) [28]. The Ki67 expression was subdivided into low (< 20%), intermediate (20% ≤ Ki67 < 50%) and high (≥50%) [29,30]. Molecular subtypes were luminal A, luminal B, HER2 and triple negative (TN) based on the results of the immunohistochemistry assay [11,31].…”