Types and stages of Breast cancer

Breast cancer can either be invasive or noninvasive.

Invasive breast cancer: as the name implies, invasive breast cancer is capable of spreading to the surrounding tissues. Invasive breast cancer is further divided into two types: infiltrating ductal carcinoma and infiltrating lobular carcinoma. Infiltrating ductal carcinoma penetrates the wall of the ducts of the breast and continues to spread to areas outside the walls of the ducts. 

Infiltrating lobular carcinoma on the other hand spreads through the walls of the lobules of the breast and continues to spread outside the lobules.

Noninvasive breast cancer

These are cancers that are found in situ.Noninvasive breast cancer has two types:  ductal carcinoma in situ (DCIS) and lobular carcinoma in situ (LCIS). DCIS are found only within the ducts while LCIS are found only within the lobules.

anatomy of the female breast showing the ducts and lobules of the breast

Depending on whether cancer is invasive or noninvasive, breast cancer is divided into stages using a scale from 0 to IV. the classification of breast cancer into stages depends on the following:

• The size of the tumour within the breast
• The number of lymph nodes affected
• Whether or not the breast cancer has invaded other body organs

Stage 0

This is for cancer cells that are in situ and have not spread to the surrounding breast tissue. Lobular Carcinoma in situ (LCIS) and ductal carcinoma in situ (DCIS) are of stage 0

Stage I

Stage I refers to cancer cells that have not spread beyond the breast and are less than 2 cm in size

Stage II

Stage II is used to describe:

• Tumours that have spread to the lymph nodes under a woman’s arm and the tumour is  less than 2 cm in size
• Tumours that has not spread to the lymph nodes under the arms of a woman, but the tumour is greater than 5 cm
• Tumours that are between 2 and 5 cm and may have spread to the lymph nodes
• Tumours that are between 2 and 5 cm and have not spread to the lymph nodes

Stage III

Stage III is used to describe tumours that are greater than 5cm in size and has spread to the lymph nodes under the arm.

Stage IV

Stage IV is also known as metastatic cancer. this is because the cancer has spread to other parts of the body. 

For a detailed further reading on the stages of breast cancer and sub stages, see the sources below

Sources:

BREASTCANCER.ORG

CancerAustralia