Ki-67 Expression by Immunohistochemistry and Quantitative Real-Time Polymerase Chain Reaction as Predictor of Clinical Response to Neoadjuvant Chemotherapy in Locally Advanced Breast Cancer

Abstract EN

Background.

Chemotherapy has become a standard of treatment in managing breast cancer.

To achieve proper treatment for the right patients, the predictive marker is needed.

Ki-67 is a biomarker of proliferation for solid tumor.

Studies mentioned association of Ki-67 expression with chemotherapy response.

The study aims are to evaluate whether Ki-67 expression detected by immunohistochemistry (IHC) and quantitative real-time polymerase chain reaction (qRT-PCR) may predict clinical response to neoadjuvant chemotherapy in breast cancer.

Methods.

This study utilized a longitudinal study.

IHC and qRT-PCR methods were used for detection of Ki-67 expression.

Chemotherapy response was calculated using RECIST.

Data were analyzed with Chi-square and Wilcoxon’s test.

Results.

There were 48 subjects in this study.

Analysis of Ki-67 expression with chemotherapy response has a significant correlation with p=0.025 (<0.05), OR: 1.69, confidence interval (95% CI) 1.022–2.810.

Analysis of Ki-67 mRNA expression with chemotherapy response has a significant correlation p=0.002 (<0.05), OR: 6.85, confidence interval (95% CI) 1.064–44.193.

Detection of Ki-67 expression using IHC and qRT-PCR has similar results, p=0.012 (<0.05).

Conclusion.

These results suggest that Ki-67 expression detected by both IHC and qRT-PCR is considered to be a predictor of clinical response to neoadjuvant chemotherapy in locally advanced breast cancer.