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Updated: Sep 26, 2026

Detection of Aggregation-Prone Behavior in Mutant P53 V157F Breast Cancer Cells Using Multipoint Thioflavin T Fluorescence
Published on: December 30, 2025
p53 expression and resistance against paclitaxel in patients with metastatic breast cancer
M Schmidt1, A Bachhuber, A Victor
1Department of Obstetrics and Gynaecology, University Hospital Mainz, Langenbeckstrasse 1, 55131, Mainz, Germany. MarcusSchmidtMD@aol.com
Purpose:
Paclitaxel is an important agent in the pharmacological treatment of metastatic breast cancer. Despite its efficacy in selected patients, the majority of patients have a resistance against paclitaxel. The aim of this study was to identify the responding patients and hence prevent the other patients from ineffective treatment. Identifying these patients could spare them an ineffective treatment and could in turn characterize a subgroup of patients with a higher response rate.
Material And Methods:
Thirty-three patients with metastatic breast cancer received paclitaxel 175 mg/m(2 )either as first- (15 patients) or as second-line (18 patients) treatment. Immunohistochemistry was performed on the blocks of the primary tumors with monoclonal antibodies against p53, HER-2/ neu, P-glycoprotein, Glutathione-S-Transferase-pi, and beta-tubulin II. The expression of those factors was then correlated with the objective response to paclitaxel.
Results:
Ten of 33 patients had an objective response to treatment. A significant correlation with the objective response was found for the expression of p53. None of the tumors with p53 expression ( n=11) responded to paclitaxel. In contrast, 10 of the 22 patients without p53 expression showed an objective response ( P=0.013). Expression of HER-2/ neu, P-glycoprotein, Glutathione-S-Transferase-pi, and beta-tubulin II did not show a correlation with the response to paclitaxel.
Conclusion:
The immunohistochemical detection of p53 characterizes patients with metastatic breast cancer unlikely to respond to paclitaxel.
Insights
Detecting p53 protein expression in tumors can identify patients with metastatic breast cancer unlikely to respond to paclitaxel treatment. This helps avoid ineffective therapies and targets treatment for better outcomes.
Area of Science:
- Oncology
- Pharmacology
- Molecular Biology
Background:
- Paclitaxel is a key treatment for metastatic breast cancer.
- Most patients develop resistance to paclitaxel, limiting its effectiveness.
- Identifying non-responders can prevent unnecessary treatment and costs.
Purpose of the Study:
- To identify biomarkers predicting response to paclitaxel in metastatic breast cancer.
- To differentiate patients likely to benefit from paclitaxel versus those unlikely to respond.
- To characterize a subgroup of patients with a higher paclitaxel response rate.
Main Methods:
- Thirty-three metastatic breast cancer patients received paclitaxel.
- Immunohistochemistry assessed p53, HER-2/neu, P-glycoprotein, GST-pi, and beta-tubulin II expression in primary tumors.
- Expression levels were correlated with objective response to paclitaxel.
Main Results:
- Ten out of 33 patients responded to paclitaxel.
- p53 expression strongly correlated with non-response (0/11 responders).
- No significant correlation was found for HER-2/neu, P-glycoprotein, GST-pi, or beta-tubulin II.
Conclusions:
- Immunohistochemical detection of p53 is a predictive biomarker for paclitaxel response in metastatic breast cancer.
- p53-positive tumors are unlikely to respond to paclitaxel.
- This finding can guide treatment decisions and spare patients ineffective therapy.

