Clinical Report: Evaluation of Ki-67, ER, and PR Levels as Predictors of NAC Response

Overview

This study evaluates the predictive efficacy of Ki-67, estrogen receptor (ER), and progesterone receptor (PR) levels on the effectiveness of neoadjuvant chemotherapy (NAC) in breast cancer patients.

Background

Breast cancer remains a leading cause of cancer-related morbidity and mortality among women globally. Neoadjuvant chemotherapy (NAC) is increasingly utilized to downstage tumors and improve surgical outcomes. However, the variability in patient responses to NAC necessitates the identification of reliable biomarkers to tailor treatment strategies effectively.

Data Highlights

Key Findings

• High Ki-67 expression is an independent predictor of favorable response to NAC.
• ER positivity and PR positivity are independent risk factors for NAC ineffectiveness.
• Clinical stage and molecular subtype significantly differ between responders and non-responders.

Clinical Implications

The assessment of Ki-67, ER, and PR levels prior to NAC can aid in predicting treatment responses in breast cancer patients.

Conclusion

The study highlights the association of Ki-67, ER, and PR levels with NAC efficacy in breast cancer patients.

Related Resources & Content

1. Archives of Gynecology and Obstetrics, 2026 -- The predictive role of Ki67 in pathological complete response (pCR) and invasive disease-free survival (IDFS) in HER2-positive breast cancer: a bi-centric retrospective cohort study of 244 cases
2. Frontiers in Oncology, 2026 -- Predictive value of Ki-67 expression in predicting pathological response to neoadjuvant chemotherapy combined with immunotherapy in lung squamous cell carcinoma
3. The ASCO Post, 2024 -- Neoadjuvant Chemoimmunotherapy Improves Pathologic Complete Response Rates in Subgroup Analysis of KEYNOTE-756 Related Articles
4. The ASCO Post, 2016 -- ASCO Guideline on Use of Biomarkers to Guide Decisions on Adjuvant Systemic Therapy in Early-Stage Invasive Breast Cancer
5. Estrogen and Progesterone Receptor Testing in Breast Cancer: ASCO/CAP Guideline Update
6. Assessment of Ki67 in Breast Cancer: Updated Recommendations From the International Ki67 in Breast Cancer Working Group
7. Pan-Asian adapted ESMO Clinical Practice Guidelines for the diagnosis, treatment and follow-up of patients with early breast cancer
8. Optimal Adjuvant Chemotherapy and Targeted Therapy for Early Breast Cancer—Cyclin-Dependent Kinase 4 and 6 Inhibitors: ASCO Guideline Rapid Recommendation Update
9. Does immunohistochemical marker conversion affect the prognosis in breast cancer patients receiving neoadjuvant chemotherapy? | Scientific Reports
10. Predictors of pathologic complete response in triple‑negative breast cancer treated with neoadjuvant chemotherapy: a systematic review and meta-analysis - PubMed
11. Impact of estrogen receptor expression levels on chemo-responsiveness and prognosis of breast cancer patients treated with neoadjuvant chemotherapy | npj Breast Cancer
12. Distinct ER and PR expression patterns significantly affect the clinical outcomes of early HER2-positive breast cancer: A real-world analysis of 871 patients treated with neoadjuvant therapy - ScienceDirect
13. Pathologic Complete Response after Neoadjuvant Chemotherapy and Impact on Breast Cancer Recurrence and Survival: A Comprehensive Meta-analysis | Clinical Cancer Research | American Association for Cancer Research
14. Frontiers | Defining the optimal Ki67 cutoff values for survival prediction in neoadjuvant chemotherapy-treated patients with breast cancer