About TNBC

What is TNBC?

Triple-negative breast cancer (TNBC) is a type of breast cancer where cells lack estrogen receptors, progesterone receptors, and excess HER2 receptors. That is why it is called “triple-negative”.1

What is TNBC

Due to the absence or the low number of these receptors, treatments that work for other types of breast cancer may not be an option for people with TNBC.1

What are the signs and symptoms of TNBC? What are the signs and symptoms of TNBC?2

TNBC can have the same signs and symptoms as other common types of
breast cancer, such as:

TNBC can have the same signs and symptoms as other common types of breast cancer, such as:

Many of these symptoms can also be due to other less serious conditions. It is important to have any new breast lump, mass, or other breast changes checked by an experienced healthcare professional.

Risk factors
Risk factors Risk factors

Who has a higher chance of getting TNBC?

Among women with breast cancer, about 10-15% (or about 1 in 10) have TNBC.3

Anyone can get TNBC. However, it is more common in women with harmful gene variants that increase the likelihood of breast cancer (BRCA1/2 mutations).4

Studies also suggest that younger women under the age of 40 years diagnosed with breast cancer are nearly twice as likely to have TNBC than those aged >60.5

Other factors that appear to affect one’s risk of having TNBC include:4

Screening and diagnosis
Screening and diagnosis Screening and diagnosis

What are the screening tests for breast cancer?6

Screening may be performed in people at risk of breast cancer, even when they don’t have any symptoms yet. The goal of screening is to find cancer early, before it causes symptoms (like a lump in the breast that can be felt).

A screening test called mammogram uses low-dose x-rays to detect breast changes years before physical symptoms of breast cancer develop. Women who have regular mammograms are more likely to have breast cancer found earlier, are less likely to need aggressive treatments, and are more likely to be cured.

How is TNBC diagnosed?3

Once a breast cancer diagnosis is made, a sample from the breast biopsy will be examined for the presence of certain proteins. If the cancer cells do not have estrogen or progesterone receptors (ER or PR), and also do not make any or too much of the HER2 protein, the cancer is considered to be TNBC.

This information guides your doctor on the appropriate strategies to treat or prevent cancer from recurring.

What are the stages of breast cancer?7

There are 4 stages of invasive breast cancer. The word “stage” describes the size of the tumor in your breast and if it has spread to your lymph nodes and other parts of your body. Lymph nodes are tiny organs throughout your body that help fight infection and disease as part of your immune system. The group of lymph nodes in your neck, underarms, and chest are common places where breast cancer may spread.

Your health care team may recommend different treatments depending on the stage
of your cancer.

Your health care team may recommend different treatments depending on the stage of your cancer.

Stages of Breast Cancer

Stage 1

  • The earliest stage of invasive breast cancer, meaning the cancer grown or spread into nearby or surrounding breast tissue
  • The tumor is 2cm or smaller (about the size of a peanut)
  • Cancer either has not spread to lymph nodes or may show microscopic spread to lymph nodes

Stage 2

  • The tumor may have started to grow up to 5cm (about the size of a lime) and sometimes larger
  • Cancer may or may not start to appear in the lymph nodes

Stage 3

  • Cancer has usually spread to lymph nodes

Stage 4

  • This stage means the cancer has spread beyond the breast and nearby lymph nodes to other parts of the body
  • Also referred to as “metastatic” cancer

1 National Breast Cancer Foundation Inc. Triple Negative Breast Cancer.[Accessed May 2023].
2 American Cancer Society. Breast Cancer Signs and Symptoms. [Accessed April 2023].
3 American Cancer Society. Triple-negative Breast Cancer. [Accessed April 2023].
4 Wang C, et al. Cancer Treat Rev. 2018;62:29-38.
5 Plasilova ML, et al. Medicine (Baltimore). 2016;95(35):e4614.
6 American Cancer Society. American Cancer Society Recommendations for the Early Detection of Breast Cancer. detection-of-breast-cancer.html [Accessed April 2023].
7 Breast Cancer Stages. [Accessed May 2023].

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