Can someone explain tumor grading to me?
When dealing with a cancer diagnosis, an important aspect of characterizing a cancerous tumor is “grading” it. This article explains what tumor grading is, and how tumors are graded.
Tumor grade describes how abnormal cancer cells look, which can help differentiate between cancer types and therefore can also aid in predicting the patient’s prognosis. If the tumor cells in question are similar in appearance to normal cells, they will be described as well-differentiated. Undifferentiated or poorly differentiated tumors tend to grow and spread more quickly because they function very differently from normal cells. Under the standard grading system, a tumor will be given a grade between 1 and 4.[1]
Tumor Grade and What it Means
| 1 | Low Grade | Well Differentiated |
|---|---|---|
| 2 | Intermediate Grade | Moderately Differentiated |
| 3 | High Grade | Poorly Differentiated |
| 4 | High Grade | Undifferentiated |
Breast cancers have a specific grading system called the Nottingham grading system which assesses if the cancer cells have normal milk ducts, nuclei, and dividing cells. Each category is given a score between 1 and 3, with 1 being closest to normal and 3 being the most abnormal. The score from each category is summed and given a score between 3 and 9.[1]
Nottingham Grading System for Breast Cancer
References
1. Tumor Grade Fact Sheet https://www.cancer.gov/about-cancer/diagnosis-staging/prognosis/tumor-grade-fact-sheet (accessed Apr 27, 2021).