What Is Triple Negative Breast Cancer?

Overview

Triple negative breast cancer is considered to be an aggressive disease because it is harder to treat. It generally spreads faster and has a worse prognosis compared to other types of breast cancer.¹ It is  called ‘triple negative’ because it does not have any of the protein receptors found in other types of breast cancer.²

These protein receptors are: EstrogenProgesterone and Human epidermal growth factor (HER2)

The CDC provides a simple analogy describing these receptors as locks on a door which can be opened by using a range of treatments to destroy the cancer inside.  However, without these locks, the cancer is harder to treat because the treatments cannot get through the ‘door’ to reach the cancerous cells. 

The disease is fairly common, mostly affecting those patients with a gene mutation and is more common in younger breast cancer sufferers. Although this subtype is more difficult to treat, there are treatment options available and further research is being carried out to develop new treatments. 

Causes of triple negative breast cancer

Often there is no clear cause of triple negative breast cancer.

Sometimes, an inherited gene can predispose a person to certain types of cancer. One such gene is called BRCA. Harmful variants of this gene called BRCA1 and BRCA2 can be inherited from each parent and those that possess it can be at a higher risk of developing certain cancers including breast cancer. BRCA genes are tumour suppressing genes that carry out repairs on damaged DNA. Having a mutation in a BRCA gene means that its DNA-repair function is inhibited and therefore cancer is more likely to develop.

Individuals who have inherited a dangerous variant of BRCA1  have an increased chance of developing triple negative breast cancer (or other types of cancer). In the patients with the BRCA1 gene that do develop breast cancer, it is usually of the triple-negative subtype.³ However, it is  important to remember that not all individuals with a mutated BRCA gene will develop cancer and many diagnosed patients do not possess the mutation. 

Occasionally, breast cancer seems to run in families without there being an obvious gene mutation. Perhaps future research will uncover the reasons for this. In addition, the majority of people that develop cancer do not have any relatives that have suffered from the disease. This highlights the importance of getting any symptoms checked out as soon as possible. 

Signs and symptoms of triple negative breast cancer

The signs and symptoms of triple negative breast cancer are the same as other types of breast cancer:⁴

• A lump in the breast
• A change in shape of the breast such as a swelling
• An eczema-like rash on or around the nipple
• Continuous pain in the breast- this is a rare symptom
• An inverted nipple
• Discharge or blood leaking from the nipple
• A swelling or lump in the armpit
• Thickened skin on the breast
• Dimpled skin on the breast
• Other changes around the nipple

It’s important to remember that there are many benign breast conditions that can mimic the symptoms of breast cancer. However, as with all cancers, the earlier breast cancer is detected, the easier it is to treat. Patients should not delay speaking to their GP if they have any symptoms.

Management and treatment for triple negative breast cancer

Treatment depends on how big the cancer is, how far it has progressed and the patient’s general health. Treatment options will always be discussed with the patient and they will have the opportunity to ask any questions they may have. Treatment for triple negative breast cancer is more complicated than that of other breast cancer types.There are however, some  treatments that have proven effective in some cases alongside  regular clinical trials. 

Surgery

The main treatment for breast cancer is surgery to remove the cancerous cells, surgery can take different forms, all of which are explained by Cancer Research UK:

• A lumpectomy whereby some of the breast tissue is conserved and only the cancer is removed along with a small amount of surrounding breast tissue 
• A mastectomy- complete removal of the breast. Depending on the individual, this could be one or both breasts 

Chemotherapy

Chemotherapy is sometimes used before surgery to shrink the tumour. It might be helpful to think of cancerous cells like a dandelion, the majority of the seedlings clump together, but it is  likely that a few escape from the main bundle and once they have blown away, they can be hard to see. For this reason, after surgery, it is likely that a patient will undergo chemotherapy to destroy any remaining cancer cells. Chemotherapy can also kill cancer that might have travelled to elsewhere in the body. 

Radiation therapy

Radiation therapy is also often used after surgery.

Patients should speak to their doctor if they have any concerns about their treatment plan and can also ask for information about any clinical trials that they may be interested in taking part in. 

FAQs

How is triple negative breast cancer diagnosed

If a GP is concerned about a patient's symptoms or if abnormalities have been detected during a routine breast screening, the patient will be referred to a specialist breast clinic. Here, patients usually undergo a mammogram; this is an X-ray of your breast(s). An ultrasound may also be carried out. An ultrasound can determine the density of any lumps that are present; whether they are solid or fluid filled. Patients are also likely to undergo a biopsy; this is where a needle is used to take a sample of the breast tissue or lump and examined in a laboratory to evaluate whether there are cancer cells present.

Further scans such as CT or chest x-ray may also be carried out. This is usually to check if the cancer has spread further than the breast tissue.⁶

If a diagnosis of breast cancer is confirmed, the cancer cells will be investigated in a laboratory to find out what type of cancer it is. 

How can I prevent from triple negative breast cancer

As with all cancers, the best way to prevent it is to make healthy changes to your lifestyle such as ensuring that you maintain a healthy weight and an active lifestyle. Reducing alcohol intake and giving up smoking also lowers the risk of cancer. However, there are unavoidable factors that increase the likelihood of developing breast cancer such as age and family history.  

As aforementioned, having a genetic mutation in the BRCA gene can increase your likelihood of developing certain types of cancer, including triple negative breast cancer. In some cases, a strong family history of breast cancer can lead your doctor to recommend genetic testing for other members of the family. Some people that possess the mutated gene may choose to have preventative surgery to drastically reduce their probability of developing  breast cancer. 

How common is triple negative breast cancer

Breast cancer is the most common cancer in the UK. Approximately 55,000 of those assigned female at birth (AFAB), and 370 of those assigned male at birth are diagnosed each year. This is roughly one person every 10 minutes.⁷ Around 15 out of every 100 breast cancers diagnosed in the UK are triple negative.⁸

Who are at risks of triple negative breast cancer

Some people are more likely to develop the triple negative subtype of breast cancer than other breast cancer variations. These include black people AFAB who are disproportionately diagnosed with triple negative breast cancer compared to Asian or Caucasian people AFAB.⁹

Younger people AFAB (aged below 50) are also more likely to develop triple negative breast cancer along with those with a BRCA1 gene mutation.¹⁰

When should I see a doctor

You should always see a doctor as soon as possible if you have any of the signs or symptoms of breast cancer. They will quickly be able to examine you and decide whether further referrals need to be made and can discuss any worries that you might have. As with all cancers, the sooner triple negative breast cancer is diagnosed, the easier it is to treat. 

Summary

Triple negative breast cancer is fairly common making up around 15% of breast cancers diagnosed in the UK. It’s more likely to affect younger people and those with the BRCA1 genetic mutation. There are different treatment options including surgery and chemotherapy. Treatment options including surgery and chemotherapy have shown to be effective in treating triple negative breast cancer despite it being more difficult to treat than other breast cancer types. The signs and symptoms are the same as other breast cancer types and if any of the signs are noticed, a GP should be contacted immediately. The earlier the cancer is found, the easier it is to treat.