Triple-negative breast cancer-A deep dive

Triple-negative breast cancer (TNBC) is one of the rare cancers. It accounts for 10-15% of all breast cancers. However, in India, multiple reports have suggested that TNBC incidence is way higher than that-almost up to 31%. 

It has a high recurrence rate, which is the highest within the first three years. However, there’s a sharp decrease in recurrence after 5 years. 

The overall 5-year survival rate of triple-negative breast cancer is 77%. The survival rate depends on the spread of the cancer-91% for localized, 65% for regional, and 12% for distant.

What is triple-negative breast cancer?

TNBC or triple-negative breast cancer is a type of breast cancer that does not have the three receptors found commonly in breast cancer-two hormones namely estrogen & progesterone & HER2 protein. 

When these three receptors are missing, it means the growth of the cancer is not in any way, shape, or form fuelled by the said receptors. Why is this information important? Because such a result means cancer will not respond to hormonal therapy or targeted HER2 protein receptor medications. Knowing this, cancer specialists can now use other techniques to handle cancer.

3 top features of TNBC

• More aggressive & has a poorer prognosis than other types of breast cancer. 

Since there are fewer targeted medications to treat it, and because it is more likely to spread beyond the breast as well as recur after treatment, it is considered to be more deadly. 

• Is often higher grade than other breast cancers

TNBC tends to be more high-grade than other types of breast cancer, and that is critical. Why? Because the higher the grade, the lesser the cancer cells resemble healthy breast cells in appearance & growth pattern. In fact, on a scale of 1 to 3, TNBC is often graded 3. 

• It has “basal-like” cells

TNBC cells resemble basal cells lining the breast ducts, so they’re called “basal-like.” It is bad because “basal-like” cancers are more aggressive, higher grades. Most basal-like cancers are triple-negative, and most TNBCs are basal-like.

Triple-negative breast cancer causes

Some of the causes & risk factors of TNBC according to cancer specialists are: 

• Age (Increase)
• Family history of TNBC or breast cancer
• Personal history of TNBC or breast cancer
• Certain benign breast diseases like atypical hyperplasia
• Your age at menstruation and late menopause
• Dense breast tissue
• Radiation exposure
• Never having given birth or giving birth after the age of 30
• Obesity
• Using postmenopausal hormonal therapy
• Genetic risk factors (BRCA-1 and BRCA-2 mutations)
• Alcohol consumption

You should note that these are the risk factors for most breast cancers and are not limited to TNBC. Also, any of the factors do not guarantee TNBC or other breast cancers.

Triple-negative breast cancer symptoms

Triple-negative breast cancer, although aggressive, often does not cause any symptoms. The most common sign is a hard mass in the breast. 

Some other symptoms are:

• Changes in breast skin
• Lumps or masses in the armpits
• Changes in the nipple like discharge or inversion

Who can get triple-negative breast cancer?

The simple answer is-anyone can get TNBC. However, according to cancer specialists & researchers, it is more common in:

• Young People

People younger than 50 years old are more likely to be diagnosed with triple-negative breast cancer. 

• People of color

Black & Hispanic women are more likely to be diagnosed with TNBC, while Asian women and non-Hispanic white women are less likely to be diagnosed with it. 

• People with BRCA1 mutation

People who have inherited the BRCA1 mutation are more likely to be diagnosed with TNBC. In fact, 70% of breast cancers in people with the mutation are TNBC.

Triple-negative breast cancer treatment

TNBC is typically treated with a combination of different treatments like surgery, radiation therapy, & chemotherapy. 

• Surgery

Many women with TNBC may require surgery. Broadly, the types of surgeries include lumpectomy (partial breast removal) and mastectomy (complete breast removal). 

• Radiation Therapy

Cancer specialists often recommend radiation therapy to TNBC patients after surgery, most commonly lumpectomy. The radiation destroys cancer cells with high-energy rays. 

• Neoadjuvant chemotherapy

Recent research has shown that when TNBC patients are treated with chemotherapy before surgery, the process is called neoadjuvant chemotherapy-and they can see a pathologic complete response, the chances of disease-free survival & overall survival are better. 

One way cancer specialists can judge the effectiveness of neoadjuvant treatment is to have a look at the tissue removed during surgery. They can then see if active cancer cells are present or not. If there are no active cancer cells then it is called a “pathologic complete response” or PCR.

• PARP inhibitors

Lynparza (olaparib), Talzenna (talazoparib), and many such PARP inhibitors have been approved to treat advanced-stage HER2-negative breast cancer in people with a BRCA1 or BRCA2 mutation.

PARP is poly ADP-ribose polymerase. It is an enzyme that fixes DNA damage in healthy as well as cancer cells. Research has shown that medicines interfering or inhibiting the PARP enzyme make it harder for cancer cells with a BRCA1 or BRCA2 mutation to fix DNA damage. This, in turn, makes it difficult for cancer cells to survive. 

• Immunotherapy

Immunotherapy is also a suggested treatment for TNBC. It works by helping the body’s immune system act harder or smarter in attacking cancer cells. 

Tecentriq (atezolizumab) in combination with chemotherapy medicine Abraxane (albumin-bound paclitaxel or nab-paclitaxel), is approved to treat unresectable locally advanced or metastatic triple-negative, PD-L1-positive breast cancer.

In the end

Triple-negative breast cancer or TNBC diagnosis can seem like a difficult challenge, and it is. However, it is not the end-all of life itself. Despite its aggressive nature, TNBC is not untreatable. Many treatment options are available today to battle the cancer. All you need is the right oncologist, the right kind of knowledge, and the right support to go through such a journey. So, don’t lose hope and keep the fight going.

Note

Dr. Manish Singhal is a leading cancer doctor in Delhi NCR. He and his team have handled multiple cases of triple-negative breast cancer successfully and administered the latest, most suitable to such patients.  The team is knowledgeable & well equipped to manage all types of cancer, inclusive of aggressive subtypes like TNBC.