Triple Negative Breast Cancer

Triple Negative Breast Cancer is the most common cancer in women with different characteristics according to morphological, clinical, hormone receptor level, and response to treatment.

The most distinctive feature that distinguishes triple negative breast cancer (TNBC) from other breast cancers is that the receptors on the cancer cell surfaces are negative. In other words, it is the absence of these three receptors, which are referred to as estrogen hormone receptor (ER), progesterone hormone receptor (PR), and human epidermal growth factor receptor 2 (HER2).

Triple Negative Breast Cancer Symptoms

The most common sign is a painless, hard mass in the breast. However, in some cases of TNBC, there are no symptoms at all. Other less common symptoms can include:

• Changes in the skin of the breast
• Lumps or masses felt in the armpit
• Changes in the nipple
• Breast pain, warmth, irritation, itchiness or hardness
• Change in the size or shape of one or both breasts

Triple Negative Breast Cancer Causes

Some breast cancer cells can also be driven by hormones called estrogen and progesterone.  The breast cancer cells may have receptors on their surfaces that carry these hormones in the body.   When the tumor is tested by taking a sample by biopsy or surgery, the cells are checked to see if the breast cancer cells may have one, both, or none of these receptors:

• Estrogen receptor (ER) positive: tumor has estrogen receptors
• Progesterone receptor (PR) positive: tumor has progesterone receptors
• Hormone receptor (HR) positive: tumor has one or both estrogen or progesterone
• Hormone receptor (HR) negative: tumor does not have estrogen or progesterone receptors

Breast cancer is also closely related to environmental factors. Lifestyle, dietary habits, and genetic factors can increase the risk of developing breast cancer. Today, excessive weight gain or obesity, because of unbalanced nutrition, increases the risk of breast cancer. The risk of breast cancer also increases in women who do not have children or have children at a late age. In addition, gene mutations, such as BRCA1 and BRCA2, can be identified and help determine hereditary risk factors.

TNBC Risk Factors

Obesity and increased body mass index increase the risk of triple negative breast cancer. Among the reasons for this situation is a sedentary lifestyle along with an unhealthy diet. As with other types of cancer, individuals with mutated genes, inherited from parents or developed over a lifetime, have a higher risk of developing triple negative breast cancer.

According to some studies, older age also affects the risk of developing triple negative breast cancer. Pre-menopausal triple-negative breast cancer risk is higher than post-menopause. Additionally, according to other data, TNBC is more common in African American women. Pregnancy history in women can increase or decrease the risk of triple-negative breast cancer. The risk of this type of cancer is higher in women who have children compared to those who do not.

• Triple negative breast cancer occurs most often in young women
• African-American women are at greater risk
• Having a family history of breast cancer increases your risk
• A history of multiple breast biopsies or breast biopsy showing atypical cells
• Being BRCA1 or BRCA2 positive.
• Being obese
• Getting pregnant for the first time after age 30
• Getting cancer in a breast

Triple Negative Breast Cancer Molecular Subtyping

Breast cancer is a highly heterogeneous disease. Much smaller tumors can be seen to metastasize through an aggressive, hematogenous way. Clinical treatment and prognosis varies greatly between patients. Definition of breast cancer molecular subtypes:

• Luminal A (ER/PR+, HER2)
• Luminal B (ER/PR+, HER2− or ERBBD2-) – (HER2+ B2 “ER/PR+, HER2 overexpression”)
• HER2 overexpression (ER−, PR−, HER2 overexpression)
• Basal-like TNBC (ER−, PR−, HER2−)

Triple Negative Breast Cancer Treatment

Triple negative breast cancer has fewer treatment options than other types of breast cancer. This is because the cancer cells do not have the estrogen or progesterone receptors, hormone therapy, or enough HER2 protein for drugs targeting those receptors to work. The main treatment of advanced stage TNBC today is chemotherapy.

In recent years, it has become increasingly clear how cancer cells escape from the immune system. As a result, targeted drugs have been developed that prevent and kill cancer cells from the immune system called “immunotherapy”. The most promising breast cancer type for immunotherapy is TNBC which is defined as “multi-personality”. The most recent developments are taking place in drugs that act on the immune system. Studies of certain drugs which have already been approved for malignant melanoma, head and neck, and lung cancers, continue in TNBC patients.

Can You Be Cured From Triple Negative Breast Cancer?

If the cancer has not spread to different areas of the body, surgery is an option for treatment in the early stages. In order to shrink a large tumor, the patient can be treated with chemotherapy until they are eligible for surgery. Treatment success for patients with triple negative breast cancer will vary for each patient because each cancer case is different. Thus, there is no known absolute cure for triple negative breast cancer.

Triple Negative Breast Cancer Clinical Trials

Chemotherapy is the most effective treatment method for TNBC patients. However, as in all types of cancer, clinical studies are ongoing evaluating all breast cancers, including triple negative breast cancer. When some recent clinical findings were examined, chemotherapy combined with immunotherapy was shown to help increase effectiveness.

There are currently drugs that are approved for malignant melanoma, head and neck, and lung cancers that are being studied in TNBC patients. Patients in clinical trials are monitored very carefully during and after treatment. If the treatment that is being studied successfully passes all stages of the clinical trial and obtains FDA approval, it becomes an approach that can be given to many patients.