by Dr Justus Apffelstaedt, specialist surgeon with an interest in breast, thyroid and parathyroid health as well as soft tissue surgical oncology.
As soon as patients are diagnosed with breast cancer, further tests must be run to establish what stage the cancer is at. “Understanding the different stages of breast cancer allows patients to have a better comprehension of their disease while understanding the life expectancy related to each stage,” says Dr. Apffelstaedt, specialist surgeon with an interest in breast, thyroid and parathyroid health as well as soft tissue surgical oncology.
Staging breast cancer is an integral part of the patient’s journey in understanding their disease. It allows the patient and their medical team to have a better look at the progression of the disease: how large the tumour is, and whether the cancer has spread locally in the breast or in other organs or tissues in the patient’s body, as well as helping the patient understand their survival chances.
Breast cancer occurs in five stages. To determine the stage, specialists usually make a decision according to the TNM stage and grade of the cancer. TNM stage categorises breast cancer from the size of the tumour (T), whether the tumour has spread to lymph nodes (N), and whether the tumour has developed anywhere else in the body (M stands for metastases)[1]. The stage of cancer is revealed with a roman number from 0 to IV.
According to CANSA[2], the five stages of breast cancer are outlined as follows, with the related life expectancy (SEER)[3] alongside:
- Stage 0: A cancer has been found at screening by either mammography or ultrasound. There is no mass palpable in the breast. The long-term survival of these cancers is the same as for a woman of the same age without breast cancer.
- Stage 1: Breast cancer is located in the breast. The tumour is not larger than 2cm and has not spread to the surrounding tissues and underarm lymph nodes. The five-year relative survival rate for this stage is close to 100%.
- Stage 2: This stage has a survival rate of about 90% at five years. It is divided into two categories.
- IIA, the tumour is less than 2cm but has spread to the underarm lymph nodes, or is bigger than 2cm, but no larger than 5cm, and has not spread to surrounding lymph nodes.
- IIB the tumour has grown between two and 5cm and has spread to up to three underarm lymph nodes, or the tumour is larger than 5cm, but has not spread to the surrounding lymph nodes.
- Stage III: At stage III, the five-year relative survival rate begins to decline markedly to about 80%
- IIIA: The tumour is larger than 2cm but smaller than 5cm, but has spread to up to nine auxiliary underarm lymph nodes.
- IIIB: The cancer has spread to tissue near the breast including the skin, chest wall, ribs or lymph nodes in the chest wall or above the collarbone.
- Stage IV: This stage is the most serious, with a five-year survival relative rate of about 30%. Here, the cancer has spread to other organs or tissues such as the liver, lungs, brain, bones, or lymph nodes near the collarbone.
Another category, not considered as a stage, also occurs. This is when the cancer comes back. Called recurrent cancer, it is known as such because it is not a new cancer – the tumour reappears. If the cancer comes back in the same place, it is known as “local recurrence”; if it occurs in other organs or tissue, it is named “metastases”.
The above relative rates are based on the chance of survival five years after being diagnosed with breast cancer, compared to the general population who do not have cancer, and share identical characteristics such as age and gender. Those rates are only estimations. They have to be considered carefully and discussed with a specialist, as other factors can influence life expectancy, such as family history, type and characteristics of the cancer, the treatment, and how the cancer responds to treatment.
[1] Cancer association of South Africa, http://www.cansa.org.za/files/2017/08/Fact-Sheet-Breast-Cancer-in-Women-NCR-2012-web-August-2017.pdf
[2] Cancer Association of South Africa, CANSA
[3] SEER , the surveillance, ,Epidemiology and End result program of the National Cancer Institute of United-States