A low Ki-67 score, based on medical pathology, refers to a Ki-67 index of 2% or lower.
Understanding the Ki-67 Index
The Ki-67 index is a crucial marker used in pathology to measure the proliferation rate of cells, indicating how quickly they are dividing and growing. It helps clinicians understand the aggressiveness of certain tumors, particularly neuroendocrine tumors (NETs). A higher Ki-67 index typically suggests more rapidly dividing cells, while a lower index indicates slower growth.
Defining a Low Ki-67 Score
As per the reference, a Ki-67 index of 2% or lower is considered a low score. This signifies that:
- Fewer than 2 in every 100 cells (2%) are actively dividing.
- This specific range is typically associated with a Grade 1 Neuroendocrine Tumor (WD NET G1), indicating a well-differentiated tumor with slow growth characteristics.
Ki-67 Index Ranges and Their Implications
To further illustrate, here's a comparison of different Ki-67 index ranges:
| Ki-67 Index Range | Interpretation | Associated Tumor Grade |
|---|---|---|
| 2% or lower | Fewer than 2 in every 100 cells are dividing. | Grade 1 NET (WD NET G1) |
| 3% to 20% | Between 3 and 20 cells in every 100 cells are dividing. | (Typically Grade 2 NET) |
Knowing the Ki-67 score helps healthcare professionals determine the appropriate treatment plan and predict the potential behavior of a tumor. A low Ki-67 score is generally a favorable indicator, suggesting a less aggressive tumor.
