Ki-67 index

The Ki-67 index is a measure used by doctors to understand how quickly cancer cells are dividing and growing. It is determined by examining a sample of tumor tissue under a microscope, where a special stain highlights cells that are actively dividing. A higher Ki-67 index indicates a larger proportion of actively dividing cells, suggesting a more aggressive or fast-growing cancer. Conversely, a lower index implies slower growth and generally a better outlook. This information helps doctors determine the best treatment approach and predict how the cancer might behave over time.