Ki-67 correlations in breast cancer

Area of Science:

• Oncology
• Neurosurgery
• Pathology

Background:

• Brain metastases from breast cancer significantly reduce survival and quality of life.
• Rising incidence of brain metastases is linked to increased patient survival and challenges in systemic therapy penetration of the blood-brain barrier.
• Molecular profiles of metastases can differ from primary tumors, impacting treatment decisions.

Purpose of the Study:

• To investigate the correlation between immunohistochemical profiles of breast cancer brain metastases and clinical/imaging features.
• To analyze the relationship between tumor proliferation markers (Ki-67) and metastasis latency and imaging characteristics.
• To compare treatment outcomes based on therapy type (hormonal vs. targeted) in patients with breast cancer brain metastases.

Main Methods:

• Retrospective analysis of 100 women with breast cancer brain metastases treated between 2015-2020.
• Data collection included demographics, metastasis latency, and MRI features (number, location, edema, hemorrhage).
• Histopathology and immunohistochemistry assessed ER, PR, HER2, GATA3, CK5/6, and Ki-67 expression.

Main Results:

• HER2-positive (32%) and triple-negative (25%) subtypes were most frequent.
• Mean Ki-67 index (48.2%) inversely correlated with metastasis latency (r = -0.57; P < 0.001).
• Higher Ki-67 associated with hemorrhagic lesions; lower Ki-67 with solitary metastases. Hormonal therapy yielded longer median survival (29.5 months) than targeted therapy (11.9 months; P < 0.001).

Conclusions:

• Immunohistochemistry of brain metastases reveals correlations between proliferation, metastasis time, and imaging features.
• HER2-positive and triple-negative subtypes show higher metastatic potential and poorer outcomes with targeted therapy.
• Luminal tumors respond better to hormonal therapy; tailored strategies integrating pathology and imaging are essential.