New hope for breast cancer: Let's learn about PI3K Inhibitors in a simple way (PI3K Inhibitors for ER+ Breast Cancer)

When we hear the word breast cancer, many of us are afraid. But the most important thing we need to understand is that not all breast cancers are the same. There are different types of them. One of the most common types is 'estrogen receptor positive' or as we medically call it , ER+ (Estrogen-Receptor-Positive) breast cancer . In fact, only 80% of breast cancers diagnosed belong to this type. So today we are going to talk about a new, successful class of drugs that have been discovered to treat these ER+ breast cancers.

First, let's see, what is ER+ breast cancer?

To put it simply, the hormone estrogen in our body helps these cancer cells grow. Imagine that these cancer cells have special 'locks' (receptors) on their surface that the estrogen hormone can attach to. When the 'key' called estrogen hormone fits into this 'lock', the cancer cells receive a 'signal' to divide and grow.

This is why doctors often give hormone therapy to treat ER+ cancers. These treatments stop the 'key' (estrogen) from binding to the 'lock' (receptors). But sometimes, especially when the cancer has spread throughout the body (advanced or metastatic), these cancer cells become very cunning. They become resistant to these hormone treatments, meaning they don't respond as well to treatment. This is when we need new, more effective treatments.

The 'growth switch' of cancer cells - PI3K and PIK3CA genes

As doctors and scientists searched for the causes of these hormone-resistant cancers, they found something special: a defect in the PI3K (Phosphatidylinositol-3-Kinase) pathway , a key signaling system that controls the growth, division, and survival of cells in our body.

Think of this PI3K pathway as a major 'switchboard' in a cell. It controls the decisions about whether a cell should grow or divide. One of the main genes that controls this switchboard is the PIK3CA gene .

In some cancer patients, this PIK3CA gene has a mutation , meaning a change or defect. It's like the 'growth' switch on the switchboard is stuck and always 'on'. Then the cells start dividing and growing uncontrollably. This is the main cause of cancer. Research has found that about 40% of patients with ER+ breast cancer have this PIK3CA gene mutation.

So what are these PI3K Inhibitors?

Here, as a solution to this problem, a class of drugs called PI3K inhibitors is being introduced. The simplest thing these drugs do is to properly deactivate the 'growth switch' (PI3K pathway) that I mentioned earlier that is stuck 'on'.

These usually come in the form of oral medications. Often, this medication is given to patients in combination with the previously mentioned hormone therapy (estrogen blocker).

How do I know if this treatment is right for me?

This is a very important question. PI3K Inhibitors are not given to all breast cancer patients. They are specifically designed to:

• For postmenopausal women and male patients.
• The cancer must be HR+ (Hormone-Receptor-Positive) and HER2-Negative .
• The most important thing: The cancer cells must have the PIK3CA gene mutation .

To find out if your cancer has this genetic mutation, your doctor will perform a special test. This usually involves a blood sample or a small piece of tissue (biopsy) taken from the tumor. The results of that test will determine whether this treatment is right for you.

What side effects can these medications cause?

Like any cancer treatment, PI3K inhibitors can cause some side effects. However, these do not occur in everyone the same way. Also, there are now ways to manage these side effects.

Some of the most common side effects are:

• Nausea and vomiting
• Loss of appetite and weight loss
• Mouth sores
• Hair loss
• Any effects on kidney, liver, or pancreas function
• Skin rashes, sometimes severe, can occur, causing the skin to peel or blister.
• High Blood Sugar: This is a common side effect specific to this class of drugs, as the PI3K pathway is involved in sugar metabolism in our body.

Don't be alarmed by these side effects. Your doctor will check you regularly for these. If necessary, he or she will reduce the dose of the medication, stop taking it for a while (medication holiday), or give you another medication to control the side effects. Never stop taking your medication or change the dose without asking your doctor.

Research has shown that taking diabetes medication to control blood sugar levels or following a low-carb, high-fat diet ( ketogenic diet ) can increase the effectiveness of this medication. However, it is important to talk to your doctor before making any dietary changes.

Is this treatment really effective?

Yes. This is the most important thing. Numerous clinical trials have shown that patients with ER+ breast cancer with a PIK3CA mutation can benefit from a PI3K inhibitor in combination with hormone therapy.

One major study found that patients who received this drug combination had a progression-free survival of about 11 months. This was less than 6 months for patients with the same genetic mutation who did not receive PI3K inhibitors. This is a big change and a great deal of hope. Because of this success, new drugs in this class of drugs are now being developed.

Breast cancer, cancer treatment, PI3K inhibitors, ER+ breast cancer, PIK3CA gene, hormone therapy, cancer drugs