IMMUNOHISTOCHEMISTRY, KI67

What this test checks

Measures the Ki-67 protein, which is present in cells that are actively dividing. The percentage of Ki-67-positive cells (proliferation index) reflects how fast a tumour is growing.

Why do people get this test?

Tumour growth rate directly affects prognosis and treatment decisions. High Ki-67 means a rapidly growing, aggressive tumour that may need more intensive therapy. Low Ki-67 may allow less aggressive treatment.

When you should consider this test

• When grading breast cancer, neuroendocrine tumours, or lymphomas
• When assessing tumour aggressiveness to guide treatment intensity
• As part of cancer prognostic panels

How to prepare

No preparation needed — performed on biopsy or surgical tissue.