Breast cancer grade is what will be part of the pathologist’s report of the breast cancer biopsy. Breast cancer grading is a powerful tool to help the doctor conclude on the type of treatment and the prognosis of the breast cancer.

This is because the grade of the breast tumor tells how fast the cancer is going to progress. The Scarf-Bloom-Richardson system is used to grade breast cancer.

Breast cancers are graded as per the following criteria:

As against that, when your doctor mentions the stage of breast cancer, he indicates the condition or the severity of the breast cancer.

The breast cancer stages tell you how much cancer has advanced or how much it has spread. There are different stages of breast cancer and each stage tells you about the condition of the breast cancer.

Staging means how large the cancer is and whether it has spread. Grading means how abnormal the cancer cells look when seen under a microscope.

Grading Breast Cancer

Grading of breast cancer simply indicates the appearance of the cancer cells – the more normal their appearance, the lower the grade and the more abnormal they look, the higher the grade of the breast cancer

There are several systems to grade breast cancer tumors. The Bloom-Richardson system has a grading system of 1 to 3.

While examining the microscopic slide prepared from the breast biopsy, the pathologist looks for three features:

  • The extent of cancer (percentage) that is composed of tubular formation
  • Mitotic activity (rate of cell division) of the tumor cells
  • Cell size and uniformity (nuclear grade)

Each of these characteristics is then given a score from 1 to 3.

  • Score 1 indicates slow-growing cancer
  • Score 2 indicates intermediate cancer
  • Score 3 indicates fast-growing cancer

The score of each of these features is added to get a total, which should be between 3 to 9.

Three grades of breast cancer

The breast tumor is graded as follows.

  • Grade 1 breast cancer
  • Grade 2 breast cancer
  • Grade 3 breast cancer

The characteristics of each grade are shown in the table below.

Total score Grade of Tumor. Appearance of cells Rate of growth.
3 to 5 Grade one Normal appearance and well-differentiated Slow growing and less likely to spread.
6 to 7 Grade two Semi normal appearance and moderately differentiated Moderate growth rate
8 to 9 Grade three Poorly differentiated and abnormal appearance Growing quickly and aggressively and more likely to spread

How do the breast cancer grades influence treatment options?

The type of your treatment will depend on the grade of your breast cancer. The higher the grade, the more aggressive the treatment will be.

The first line of treatment for grade 1 breast cancer that is contained and not spread, is surgery followed by radiation. However, chemotherapy is less likely for grade 1 and grade 2 cancers.

If you have grade 3 breast cancer, your doctor will put you on chemotherapy to destroy any cancer cells that may have spread as this grade denotes cancer that is fast growing.

Grade 4 breast cancer needs systemic treatment. Systemic therapies contain drugs that travel throughout the body to treat cancer cells wherever they may have spread. Systemic therapy includes chemotherapy, hormonal therapy, targeted drugs, and immunotherapy.

Your breast cancer grades alone will not determine the type of therapy. Other factors such as the type of breast cancer, its stage, your general health, menopause status, and personal preferences are also taken into consideration.