Grade
The grade of cancer relates to how healthy or unhealthy cells look under a microscope. In other words, a pathologist will determine the grade of cancer by comparing the amount of the healthy-looking tissue to the amount of cancerous tissue. If most of the tumor cells look like normal tissue then the cancer is “well differentiated” or “low-grade.” However, if the tumor cells look very different from normal tissue then the cancer is “poorly differentiated” or “high-grade.” The grade of cancer may help to determine how quickly the cancer is likely to spread. While some estimation of grade will often be given by the pathologist, there is no formal grading system for nasopharyngeal cancer.