Understanding Stages & Grades of Breast Cancer

15 Mar 2023

It’s estimated that 1 in 7 women will develop breast cancer in their lives. Still, even with it being so common, it’s an extremely complex disease process that requires a multilayered approach to ensure an accurate diagnosis. Breast cancer is categorised by stages and grades to help determine the most effective treatment plan. The different stages and grades of breast cancer can affect treatment options and prognosis, but early detection and treatment will help improve outcomes and quality of life.

What is breast cancer staging & why is it important?

One of the critical factors affecting the treatment and prognosis of breast cancer is the stage at which the disease is diagnosed. Staging determines the extent and spread of cancer in the body, which helps doctors to choose the most appropriate treatment and estimate the patient's chances of recovery. The staging system for breast cancer is based on:

  • The size of the tumour
  • The extent of its spread to lymph nodes and other organs
  • The presence of certain biomarkers

To help determine and describe your staging, your doctor will use the TNM system, a more personalised approach rather than a simplified description of your diagnosis.

T - describes the primary tumour’s size

N - identifies if the cancer has spread to the lymph nodes

M - explains if the cancer has spread beyond the breast tissues and into distant organs of the body such as the brain, bones or liver.

The results of the TNM system are then combined to reach an accurate staging result.

*Key terms to note during the staging process:

Regional: means that the lymph nodes are involved

Distant: cancer has spread to other organs of the body

Local: the cancer is confined to only the breast tissue

Clinical vs Pathological Staging

  • Clinical staging: includes results from physical exams, ultrasounds, mammograms, or MRI’s done before surgery.
  • Pathological staging: is based on the findings during surgery.
  • Both forms of staging are used to provide additional information about your diagnosis. However, pathological staging dives deeper into the actual tissues to obtain more accurate results.

When will I know about my staging?

Where surgery is the first line of treatment, you typically receive staging results 5 to 7 days after surgery. If you begin your treatment plan with systemic approaches such as chemotherapy, hormonal treatment, or targeted therapy, your doctor will confirm your stage clinically soon after diagnosis. 

Breast Cancer

  • Stage 0: Non-invasive breast cancer; there are no abnormal cells anywhere else in the body, and they are contained within the ducts or lobules.
  • Stage I (divided into IA or IB): Invasive; in IA, the cancer is confined to the breast tissue, is HER2-negative and presents smaller in size, around 2cm or less. In stage IB, the tumour is still small but may have spread to nearby lymph nodes, such as the armpit.
  • Stage II (divided into IIA or IIB): Invasive; at this stage, the tumour is still small, between 2-5 cm but has likely spread to the nearby lymph nodes under the armpit.
  • Stage III (divided into IIIA, IIIB, IIIC): In this stage, cancer measures larger than 5cm, is found in 4-9 axillary lymph nodes, and has spread to surrounding breast tissue, or into the chest wall, including ribs, muscle or skin.
  • Stage IV: This stage is also described as Metastatic (MBC), distant, advanced, or secondary and means that the cancer has spread to distant organs, such as the bones, brain, or lungs.

Grades of Breast Cancer

Grading is another essential factor that helps determine the severity of breast cancer. The grading system is used to evaluate how abnormal and aggressive cancer cells look under the microscope and is based on factors such as:

  • The appearance of tumour cells
  • The rate of cell growth
  • The likelihood of cancer spreading

A higher grade indicates that the cancer is more aggressive, grows quickly, and is more likely to spread. This information is crucial for doctors to determine the most effective treatment plan and achieve the best possible result. Accurate grading of breast cancer helps to estimate the patient's prognosis and likelihood of survival and is an important factor in making informed decisions regarding disease management.

Nottingham Grading System

This system describes the abnormality of the tumour cells and determines how quickly they’re growing. It will look at:

  • The size and shape of the nucleus (that “brain” of the cell)
  • The organisation of the cells and if they look like they’re working together
  • How many of the cells are dividing and growing
  • If they look similar to normal cells
  • If they form tubules

Based upon the above criteria. The cancer is then graded from 1-3:

  • Grade 1 (low): These cancer cells (often ER+) are relatively normal in appearance and grow slowly, are less aggressive and have a better prognosis.
  • Grade 2 (intermediate): Here, the cancer cells are abnormal, but not as much as Grade 3 cells and grow at a moderate rate.
  • Grade 3 (high): These highly abnormal cancer cells grow quickly, making them more aggressive and provide a worse prognosis. Grade 3 is often associated with TNBC, PR, ER, and HER2 types of breast cancer.

Staging and grading of breast cancer cells allow your doctor to choose the most effective treatment pathway and provide appropriate ongoing care. Combining this with early detection measures, such as self-breast checks and yearly screenings, will lead to better patient outcomes, a higher chance of successful treatment, and an improved quality of life. If you notice any unusual symptoms, see your GP immediately and get checked.

To learn more about breast cancer and how to reduce your risk, head to Pink Hope’s website here and check out our incredible resources.

This content is brought to you in partnership with Eli Lilly Australia and developed independently by the team at Pink Hope in consultation with medical experts