triple-negative breast cancer

Triple-negative breast cancer is the most aggressive type of breast cancer. Its difficulty when it comes to treating it lies in the absence of targets to attack.

Triple-negative breast cancer is the most aggressive and difficult-to-treat type of breast cancer. It occurs in 20% of cases.

There are three main types of breast cancer, classified based on the presence or absence of three receptors on cancer cells. So first of all, we will make it clear what a cellular receptor is.

Importance of cell receptors

The cells of the organism must communicate with their environment. They need to be able to receive signals that inform them of the conditions of the environment in which they find themselves in order to act accordingly.

For this communication to be possible, 3 elements are necessary:

A signal molecule, which is in the environment of the cell and, when detected by the cell, causes a response.
A receptor, that is, a protein present in the cell membrane capable of detecting the signal molecule and transferring the information to the interior of the cell.
Certain factors and molecules inside the cell with the capacity to respond to the signal that has been transmitted from the outside of the cell.

Thus, receptors are essential for regulating many cellular processes. Specifically, in the case of cell growth, there are receptors that detect growth factors, such as hormones (signal molecules), and transmit this information to the cell so that it grows and divides.

The problem with cancers, including breast cancer, is that cancer cells do not have this mechanism under control. Its receptors are activated when they shouldn’t and the cells proliferate uncontrollably.

But this aspect, which gives cancer cells their high dividing capacity, is also an excellent target to control cancer, using drugs against these receptors.

Types of breast cancer based on their receptors

Hormone receptors

Both in normal cells and in most cancer cells we find the so-called hormone receptors. These receptors, as the name suggests, detect hormones.

These hormones are classified into two large groups: estrogens and progesterone. Existing for them are estrogen and progesterone receptors, respectively.

Hormone receptor-positive breast cancers can be treated by targeting precisely these receptors. Thus, through hormone therapy, the proliferation of cancer cells can be slowed down or even stopped completely.

HER2 receptors

HER2 receptors are not fully characterized, so it is not known which signal molecule activates them. However, it is known that the presence of these receptors is associated with cell division.

In HER2-positive breast cancers, cancer cells have a high number of these receptors, so these cells divide uncontrollably.

But again, this offers a clear target for the treatment of such cancers. By attacking their HER2 receptors with hormone therapy, we could slow the progress of cancer.

triple-negative breast cancer

The peculiarity of this type of aggressive breast cancer is that it is negative for both estrogen and progesterone hormone receptors, as well as for HER2 receptors.

In other words, the proliferation of this type of cancer cells is not linked to hormone receptors, something that occurs in around 10-20% of breast cancer cases.

This implies, in the face of treatment, the absence of targets or “weak points” to attack said cancer. This is the reason for its poor prognosis, compared to other types of breast cancer.

In addition, triple-negative breast cancer is usually more aggressive, since it is more likely to spread outside the breasts, generating metastases. Furthermore, this type of cancer is often recurrent, meaning it can come back even after treatment.

However, all is not lost when it comes to treating triple-negative breast cancer. There are still other types of very useful treatments:

Lumpectomy of the breast: Removal of the lump from the breast and examination of nearby lymph nodes to make sure cancer has not spread.
Mastectomy: removal of the breast and examination, also, of the nearby lymph nodes.
Radiation: Radiation therapy is aimed at destroying any cancer cells that were left behind after the breast lumpectomy. It is done with high-energy radiation.
Chemotherapy: The goal of chemotherapy is to kill small cancer cells that may have spread to another part of the body. Chemotherapy lowers the chance that cancer will come back.

Finally, despite the fact that the most common treatments for other types of breast cancer have no effect in the case of triple-negative breast cancer, this does not imply the absence of other types of targets to attack in these cases.

In fact, more and more alternative treatments have emerged to treat triple-negative breast cancer and research in this field continues to advance in order to discover new therapeutic strategies.