Intermediate
Technical
IVT
Ki-67 proliferation index
Pronunciation: KAY-eye-sixty-seven
A measure of tumor cell proliferation rate based on Ki-67 protein expression, expressed as a percentage.
Full Definition
The Ki-67 proliferation index quantifies the percentage of tumor cells expressing the Ki-67 nuclear protein, which is present during active phases of the cell cycle but absent in resting cells. This biomarker provides crucial information about tumor aggressiveness and growth rate, with higher percentages indicating more rapidly dividing cancer cells. The Ki-67 index is particularly important in breast cancer grading and influences treatment decisions regarding chemotherapy intensity and prognosis assessment.
Usage
Usage note: Always express as a percentage; ensure proper hyphenation in Ki-67.
In Context
- "The invasive ductal carcinoma showed a Ki-67 proliferation index of 25%, indicating intermediate-grade tumor biology." — Breast cancer pathology report
- "A Ki-67 index above 20% in luminal breast cancers may warrant chemotherapy consideration." — Oncology treatment guideline
Also known as
Ki-67 index
proliferation rate
MIB-1 index
Don't confuse with
mitotic index
cell cycle analysis