Breast cancer types

Breast Clinic

Following your diagnosis of Breast Cancer, your consultant will usually want to carry out further tests and investigations to accurately diagnose the type of cancer you may have and to find out the stage and the grade of the cancer, which helps them determine the best treatment plan for you.


Your consultant may require you to get further scans and tests to detect the stage of your cancer. Staging defines the size of it and whether it has spread beyond its original site.

The two most commonly used systems for staging are a numbering system or the TNM staging system.

  • T describes the size of the tumour
  • N describes whether the cancer has spread to the lymph nodes
  • M describes whether the cancer has spread to another part of the body (metastatic or secondary cancer)


To identify the grade, your consultant will examine the cancer cells under a microscope to compare them to the normal cells. This gives your consultant an idea of how quickly the disease may develop.

The grading system mainly used:

  • Grade 1 or low-grade or well differentiated – The cancer cells look similar to normal cells and usually grow slowly and are less likely to spread.
  • Grade 2 or moderate-or intermediate-grade – The cancer cells look more abnormal and are slightly faster growing.
  • Grade 3 or high-grade or poorly differentiated – The cancer cells look very different from normal cells and may grow more quickly.

Ductal cancers

Ductal carcinoma in situ (DCIS)

This is an early form of breast cancer where the malignant cells are only found within the milk ducts and have not developed the ability to spread into either the breast tissue or other parts of the body. 

DCIS is sometimes described as pre-cancerous, intraductal or non- invasive carcinoma. It does not usually present any visible or palpable symptoms and is most commonly diagnosed during routine mammography.

Invasive ductal carcinoma

Most breast cancers fall within this category. Here, the cancer cells are no longer contained within the ducts and begin to spread to the surrounding breast tissue. They also have the ability to spread to other parts of the body. 

The most common sign of an Invasive Ductal Carcinoma is an abnormal lump, or sometimes an area of nodularity (glandular breast tissue) without a definite lump. Nipple changes or a nipple discharge (not usually due to cancer if there is no lump) and sometimes a swelling under the arm may also be signs of this type of cancer.

Lobular cancers

Lobular carcinoma in situ (LCIS)

The presence of LCIS may indicate that there is a small increased risk of developing breast cancer but often no treatment is required other than careful monitoring of the condition.

This is a pre-invasive carcinoma, where there are abnormal changes to the cells lining the lobules within the breast. 

Invasive lobular carcinoma

This cancer occurs when malignant cells in the lobules at the end of the breast ducts have begun to spread out into the breast tissue. When it occurs, the entire breast tends to be genetically or genomically unstable.

In some cases, this type of cancer may be found in both breasts increasing the risk slightly at a later date of occurring in the opposite breast.

These carcinomas tend to be less receptive to hormone treatment and may not show up on a mammogram as they have the same density as normal breast tissue. Fortunately, they are often palpable so it is important that everyone has a clinical examination. 

Breast Clinic
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108 Harley Street

108 Harley Street, London, W1G 7ET

+44 (0)207 563 1234