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August 23, 2024

A Basic Understanding Breast Cancer: Types, Stages & More!

Knowing that you have breast cancer is not easy. The emotions attached to the diagnosis can be hard to accept. However, it is important to remember that out of all the cancers detected in women, breast cancer is the most common one.

Being equipped with the right kind of knowledge can help you navigate your way through the maze of dealing with the disease. And that’s what we want to do today.

Let’s understand certain aspects of this disease today.


What is Breast Cancer?

Breast cancer is when breast cells mutate to become cancerous cells that multiply and develop into tumours. It is the most commonly diagnosed cancer among women not only in Malaysia but across the world. However, it does not affect women only. Even men are sometimes diagnosed with this disease.

Usually, it develops in women aged 50 and above, however, it can affect younger women too.


Symptoms of Breast Cancer

The most common symptoms of breast cancer include:

  • A lump in the breast or a thickened area of the skin that might feel different from the skin of the surrounding area.
  • Changes in the colour of the breast skin. In people with white skin, the breast skin may look red or pink. In people with brown or black skin, the breast skin may look darker and red or purple.
  • A nipple that looks flattened or turned inward.
  • Changes in the appearance of the breast or the size or shape of the breast.
  • The skin of the breast looks dimpled or feels like an orange peel.
  • Scaling, crusting, flaking or peeling of the skin of the breast.

Types of Breast Cancer

Breast cancer can be of different types based on where it starts. The more common types of breast cancer are:

Invasive ductal carcinoma (IDC)

A very common type of breast cancer, this cancer starts in the milk ducts and spreads to nearby breast tissue.

Lobular breast cancer

This kind of breast cancer starts in the lobules, the milk-producing glands and sometimes spreads to the nearby breast tissue. This kind of breast cancer is also quite common.

Ductal carcinoma in situ (DCIS)

This breast cancer also starts in the milk ducts but does not spread beyond the milk ducts.


Lesser common breast cancers are:

Triple-negative breast cancer

This is an aggressive breast cancer that spreads more quickly than other kinds.

Inflammatory breast cancer

This is a rare kind of breast cancer which is quite fast-growing and looks like a rash on the breast.

Paget’s disease of the breast

Another very rare form of cancer, this affects the skin around the nipple and looks like a rash.


Subtypes of Breast Cancer

Breast cancer is also divided into subtypes based on the status of protein molecules in or on the cells’ surfaces known as receptor cells. They attach to or attract certain substances in the blood including hormones like oestrogen and progesterone. These hormones help the cancerous cells to grow. Hence healthcare providers aim to find out if cancerous cells have oestrogen and progesterone to plan the breast cancer treatment pathway.

Based on the hormone status, breast cancer is divided into the following subtypes:

  • ER-positive (ER+) breast cancers have oestrogen receptors.
  • When breast cancer has progesterone receptors, it is known as PR-positive (PR+) breast cancer.
  • HR-positive (HR+) breast cancers have both oestrogen and progesterone receptors.
  • HR-negative (HR-) breast cancers do not have oestrogen and progesterone receptors.
  • HER2-positive (HER2+) breast cancers have higher than normal levels of HER2 protein. These protein helps cancer cells to grow.

Breast Cancer Staging

One of the primary things to know concerning breast cancer is the staging of the disease. Staging can have a direct impact on how serious your cancer is and in turn, your prognosis. The lower the number, the less the cancer has spread and the less serious the cancer is. However, it is important to remember that everyone’s experience of breast cancer is different and has to be treated differently.

How is the Stage of a Breast Cancer Determined?

The most commonly used staging system for breast cancer is the one recommended by the American Joint Committee on Cancer. Known as the TNM system, this is based on:

The Pathologic Stage

Pathologic stage or surgical stage, determined by examining the tissue removed during surgery.

The Clinical stage

Clinical stage is where surgery is not possible. This stage is determined based on examination, biopsy and imaging tests.

The clinical stage is primarily used to design the treatment plan. However, if the cancer has spread further than the clinical stage, then the pathologic stage is used to determine the stage correctly.

7 key things are considered in both the staging systems:

  1. The size (extent) of the tumour (T) shows how large is the cancer and if it has grown to nearby areas.
  2. Whether it has spread to nearby lymph nodes (N) and if yes, how many?
  3. The extent of spread (metastasis) to distant sites (M)e. whether it has spread to distant organs such as the liver or lungs.
  4. The oestrogen receptor (ER) status is as in whether the cancer has a protein called estrogen receptor.
  5. Progesterone receptor (PR) status is whether the cancer has a protein called progesterone receptor.
  6. HER2 status of the cancer which means whether the cancer cells are making too much of HER2 protein.
  7. Grade of the cancer as in whether the cancer cells look like normal cells.

Based on these 7 factors, the stage of the cancer is determined. Staging based on the first 3 factors is easier. Staging becomes more complex once the rest of the four factors are included.


T Categories

The T category refers to the size of the tumour and whether it has spread to the skin or chest wall under the breast. The higher the T number, the larger the tumour or wider it has spread. The categorisation is as follows:

  • TX: The primary tumour cannot be accessed.
  • T0: There’s no evidence of a primary tumour.
  • Tis: This is known as carcinoma in situ. This refers to the presence of abnormal cells inside the milk duct in the breast or Paget disease.
  • T1: The tumour is 2cm or less across.
  • T2: The tumour is more than 2cm but not more than 5cm across.
  • T3: The tumour is more than 5cm across.
  • T4: The tumour is of any size growing into the chest skin or wall. Inflammatory breast cancer is graded under this type.

N Categories

This categorisation reflects the extent of spread to the lymph nodes near the breast and if yes, how many lymph nodes are included. This staging is based on how the lymph nodes look under the microscope. The categorisation under N categories is as follows:

  • NX: When the nearby lymph nodes cannot be accessed.
  • N0: When the cancer has not spread to nearby lymph nodes.
  • N1: When the cancer has spread to 1 to 3 axillary lymph nodes and/or cancer is found in internal mammary lymph nodes.
  • N2: When the cancer has spread to 4 to 9 lymph nodes under the arm or has enlarged the internal mammary lymph nodes.
  • N3: Cancer is categorised as N3 under the following circumstances:
  • When cancer has spread to 10 or more axillary lymph nodes with at least one area where the cancer is greater than 2mm.
  • When there’s at least one area of cancer of greater than 2mm or it has spread to lymph nodes under the collarbone.
  • Cancer has enlarged the internal mammary lymph nodes or is found in at least one axillary lymph node.
  • Cancer has spread to internal mammary lymph nodes or to four or more axillary lymph nodes.
  • There’s at least one area of more than 2mm cancer spread or it has spread to the lymph nodes above the collarbone.

M Categories

This categorisation refers to the extent to which the cancer has spread to distant organs.

  • M0: When no distant spread is found both by physical examination or x-rays.
  • M1: When cancer has spread to distant organs as seen through physical exam and imaging test or through biopsy.

Causes of Breast Cancer

So, what causes breast cancer? The exact causes of breast cancer are not really known. Well, researchers have found that several factors increase the risk of breast cancer such as lifestyle choices, hormones or other environmental things. In general, it is a complex combination of genetics and the things around you.

In general, when breast cancer starts, the DNA inside the cells change and gives instructions to the cells to grow and multiply. This results in cancer cells developing too quickly while healthy cells continue to die. This leads to too many cancer cells in the body.

Sometimes the cancer cells develop into a mass called a tumour. The tumour can grow, invade and destroy healthy body tissue. With time, cancer cells spread to other parts of the body. A cancer that has spread is known as metastatic cancer.


Risk Factors of Breast Cancer

Several factors can increase the risk of someone getting breast cancer. These are:

  • Family history: Having a family history of breast cancer can increase the risk. The risk increases if family members get breast cancer at a young age. The risk is also higher if multiple family members have suffered from breast cancer.
  • A personal history of breast cancer or breast conditions: If you have already been diagnosed with breast cancer before, the risk of getting it again goes up. On the other hand, certain breast conditions such as lobular carcinoma in situ and atypical hyperplasia increase the chances of having breast cancer.
  • The age you get your periods: Having your periods before the age of 12 increases the risk of contracting breast cancer. Having menopause after the age of 55 also increases the risk.
  • Gender: Women are more likely to get breast cancer than men. However, everyone is born with some breast tissue, so anyone can get breast cancer.
  • Alcohol consumption: Drinking higher amounts of alcohol increases the risk.
  • Dense breast tissues: Breast tissue is composed of dense tissue and fatty tissue. Milk glands, milk ducts and fibrous tissues are components of dense tissue. People with dense breasts have more dense tissue than fatty tissues. It can be difficult to diagnose breast cancer in women with dense breast tissues. Having dense breasts increases the risk. If a mammogram reveals that you have dense breasts, speak to your gynaecologist.
  • Having your first child at an older age: Giving birth to your first child after attaining the age of 30 increases the risk of breast cancer.
  • Age: The risk of breast cancer increases as people get older.
  • Having never been pregnant: If you have never been pregnant, the risk goes up.
  • Inherited DNAs: Certain DNA changes increase the risk of breast cancer and can be passed on to children from parents. The most common among them I BRCA1 and BRCA2 genes, which increase the risk of getting breast cancer significantly. However, not everyone with these genes gets cancer.
  • Obesity: The risk of breast cancer is higher in obese people.
  • Menopausal hormone therapy: If you have been taking hormone medicines to control menopausal symptoms, you may be at risk of contracting breast cancer. These hormone therapy medicines combine oestrogen and progesterone, which increase the risk significantly. The risk reduces once you stop taking these medicines.
  • Radiation exposure: If you have taken radiation as a child or young adult, you may be at a higher risk of getting breast cancer.

Breast Cancer – A Final Word

When it comes to breast cancer, early detection is key. Diagnosing cancer at an early stage means that it hasn’t spread too much or the tumour is not too large. This improves the prognosis significantly.

Spotting cancer at an early stage can make a world of difference to survival and hence it is important to tell your doctor as soon as you notice any of the symptoms or feel something is wrong with your breast.

Early screening will help to detect diseases, take control of your health with our Women’s Wellness Screening Package.



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