Question 1

What is the Meaning of Ki-67 Proliferation Index?

Accepted Answer

The Ki-67 Proliferation Index quantifies the percentage of cells actively undergoing division within a tissue sample. It identifies a nuclear protein, Ki-67, present during all active phases of the cell cycle, including G1, S, G2, and mitosis, but absent in resting G0 phase cells. This index directly measures cellular growth rate.

Question 2

What is the Context of Ki-67 Proliferation Index?

Accepted Answer

This index operates primarily within cellular pathology, particularly in oncology. It provides critical insight into the biological behavior of neoplastic tissues. In hormone-sensitive cancers, cellular division rate, indicated by Ki-67, can be influenced by or responsive to endocrine signaling, affecting tumor growth and progression.

Question 3

What is the Significance of Ki-67 Proliferation Index?

Accepted Answer

The Ki-67 Proliferation Index holds substantial clinical significance as both a prognostic and predictive biomarker in various cancers. A higher index generally correlates with more aggressive tumor behavior and faster growth, influencing treatment selection, often guiding intensive therapies. It assists clinicians in estimating disease recurrence potential and guiding patient management, providing valuable information for individualized care.

Question 4

What is the Mechanism of Ki-67 Proliferation Index?

Accepted Answer

The mechanism behind the Ki-67 Proliferation Index involves the direct expression of the Ki-67 protein within the nucleus of proliferating cells. This protein is essential for cell cycle progression, specifically for ribosomal RNA synthesis and ribosome biogenesis, fundamental processes for cell growth and division. Its presence signifies active cell cycle phases (G1, S, G2, M), while its absence indicates a quiescent, non-dividing state (G0), a reliable marker for cellular reproduction.

Question 5

What is the Application of Ki-67 Proliferation Index?

Accepted Answer

In clinical practice, the Ki-67 Proliferation Index is routinely determined through immunohistochemical staining of tumor tissue obtained from biopsies or surgical resections. Pathologists examine the stained slides, counting the percentage of tumor cells exhibiting nuclear Ki-67 positivity. This numerical value is incorporated into the overall pathological assessment, assisting oncologists in classifying tumor aggressiveness and making informed decisions for patient treatment.

Question 6

What is the Metric of Ki-67 Proliferation Index?

Accepted Answer

The Ki-67 Proliferation Index is quantified as a percentage, representing the proportion of tumor cells that stain positively for the Ki-67 protein. This measurement is typically performed using immunohistochemistry on formalin-fixed, paraffin-embedded tissue sections. Pathologists visually count stained nuclei within a defined tumor area, or automated image analysis systems are employed, to derive this numerical metric reflecting the proliferative fraction.

Question 7

What is the Risk of Ki-67 Proliferation Index?

Accepted Answer

Misinterpretation of the Ki-67 Proliferation Index can lead to suboptimal clinical decisions, potentially resulting in undertreatment or overtreatment. Variability in laboratory staining protocols, differing interpretation methodologies among pathologists, and tumor heterogeneity can influence the accuracy and reproducibility of the index. Relying solely on Ki-67 without considering other clinical, pathological, and molecular factors poses a risk, as it serves as one component of a comprehensive diagnostic assessment.

Ki-67 Proliferation Index

Meaning

Context

Significance

Mechanism

Application

Metric

Risk

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