Grading uterine cancer

To find out the grade of uterine cancer, the pathologist looks at a tissue sample from the uterus under a microscope. The pathologist gives uterine cancer a grade from 1 to 3. The lower the number, the lower the grade.

The grade is a description of how the cancer cells look and act compared to normal cells. How different the cancer cells are is described as differentiation.

Low grade means that the cancer cells are well differentiated. They look almost like normal cells. Lower grade cancer cells tend to be slow growing and are less likely to spread.

High grade means that the cancer cells are poorly differentiated or undifferentiated. They look less normal, or more abnormal. Higher grade cancer cells tend to grow more quickly and are more likely to spread than low-grade cancer cells.

Knowing the grade gives your healthcare team an idea of how quickly the cancer may be growing and how likely it is to spread. This helps them plan your treatment. The grade can also help the healthcare team predict your prognosis and how the cancer might respond to treatment.

The International Federation of Gynecology and Obstetrics (FIGO) developed a grading system for endometrial carcinoma. It is based on the percentage of cells in the tumour that grow in sheets (called solid tumour growth) rather than form glands. It may also take into account how abnormal the cells appear.

Uterine sarcoma is a soft tissue sarcoma that begins in the muscle or connective tissue cells of the uterus. There are several grading systems used for soft tissue sarcomas. The French Federation of Comprehensive Cancer Centers (FNCLCC) system is most commonly used. In this system, the grade is based on the following 3 factors.

Differentiation: The cells are given a score of 1–3 based on how they look. A score of 1 means the cancer cells look very similar to normal cells. A score of 3 means the cells look very abnormal.

Mitotic count: The cancer cells are given a score of 1–3 based on how they are dividing. A score of 1 means the pathologist saw only a few cells dividing. A score of 3 means many cells were dividing.

Tumor necrosis: The tumour is given a score of 0–2 based on how much of it is made up of dying tissue. A score of 0 means very little tissue is dying. A score of 2 means there is a large amount of dying tissue.

The scores for each factor are added up to determine the grade of the cancer. A higher score means a higher grade.

Find out more about grading soft tissue sarcoma.