Normal breast cells and some breast cancer cells have receptors that attach to the hormones Estrogen & Progesterone and the cancer cells depend on these hormones to grow.  Breast cancer cells may have one, both or none of these receptors on their cell surface.  The breast cancer cells also have another protein called Human Epidermal growth factor type 2 Receptor (HER-2 protein) on the cell surface. 

The absence or presence of these receptors or proteins is detected using Immunohistochemistry analysis by the Histopathologist using a sample taken during your breast biopsy or after breast surgery. 

• ER-Positive.  Breast cancers with Oestrogen Receptors are called ER-positive (ER+)
• PR-Positive.  Breast cancers with Progesterone Receptors are called PR-positive (PR+)
• Hormone receptor positive. If the cancer cells have one or both receptors, they may also be called Hormone receptor positive (HR+) 
• Hormone receptor negative. If the cancer cells have neither of these receptors, they may also be called Hormone receptor negative (HR-)
• HER-2 Positive. If breast cancer cells demonstrate excess HER-2 protein, they are called HER-2+

Around 70% of breast cancers are ER-/PR-positive and rely on estrogen to grow, while about 20–25 percent of breast cancers are HER2-positive. Triple-Negative Breast Cancer (also known as TNBC) is so-named for the simple reason that the cancer cells DO NOT express any of these three receptors (namely ER, PR or HER-2).  Around 15% of all breast cancers are Triple Negative Breast Cancer and more commonly seen in breast cancers of younger women. 

Other risk factors for TNBC include;

• Never pregnant or given birth before
• Never having breast fed
• Women with BRAC1 gene mutation
• Being overweight with a high BMI

Triple Negative Breast Cancer means that your cancer cells tested NEGATIVE for the oestrogen receptor, progesterone receptor and HER-2 protein. It also means that your cancer is UNLIKELY to respond to Hormonal Therapy, but you can still go through the usual treatment for Breast Cancer.  TNBC is usually more aggressive and has a higher risk of recurrence as well as distant cancer spread to other parts of the body.

Treatment Options for TNBC

TNBC is usually treated with a combination of surgery, radiation therapy and chemotherapy.  The treatment plan may be modified by your doctors to consider of the more aggressive nature of your cancer to include some of the following;

• Neo-Adjuvant Chemotherapy.  Your breast surgeon and oncologist may decide to start the chemotherapy before your surgery and radiation
• PARP Inhibitors. Poly ADP-Ribose Polymerase (PARP) inhibitors help to block aggressive cancer cells from being able to repair and survive.  These medications include Olaparib (Lynparza) and Talazoparib (Talzenna)
• Immunotherapy. Immunotherapy drugs work by helping your immune system work smarter to attack cancer cells (especially if the cancer cells express PD-L1 protein). These medications include Pembrolizumab (Keytruda), Atezolizumab (Tecentriq) and Paclitaxel (Abraxane)

Discuss your Treatment Options with your Surgeon or Oncologist

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