Do you know about this amazing drug that targets only cancer cells? (Tyrosine Kinase Inhibitors)

When we learn that we have cancer, we all get very scared. At the same time, we think of treatments like chemotherapy. Chemotherapy destroys rapidly dividing cells. However, it can also destroy not only cancer cells, but also healthy cells in our body, for example, hair cells, cells that cause mouth ulcers, and cells in the intestines. That's why chemo causes hair loss, mouth ulcers, and stomach upset. But, imagine... how great it would be if there was a type of medicine that could target only cancer cells, like a sniper rifle? That's what we're going to talk about today. These are called Tyrosine Kinase Inhibitors , or TKIs for short.

Simply put, what are these TKIs?

TKIs are a type of targeted therapy used in cancer treatment. They work by blocking certain things inside cancer cells that help them grow and divide. In other words, cancer cells have a signaling system that tells them to "grow and divide." TKIs work by interfering with that signaling system and stopping it.

These medications may not cure cancer completely, but they can help patients maintain long-term control (remission) of the cancer, or even live a good quality of life with the cancer.

How does this medicine actually work? Let's take a look in a little more detail.

To understand this, we first need to know a little about the normal process of cell division in our body. Imagine that our body is a big factory. The workers in this factory are called cells.

1. Growth factors: These are the messengers from outside the factory that bring the message "Start production now."

2. Tyrosine kinases: These are the enzymes inside cells that take the message and tell others to "OK, let's get to work."

Here's what happens in a normal healthy cell. The messenger (growth factor) comes and gives the message to the manager (tyrosine kinase). The manager takes that message and tells the cell to divide. After the cells have divided as much as they need, the manager turns off the switch. This is a very controlled process.

But in cancer cells, this system goes haywire. In some types of cancer, in particular, these managers (Tyrosine kinases) go crazy. Their switch is permanently on. They don't need a message from outside, they just keep telling the cells to "divide, divide, divide." This uncontrolled cell division is what we call cancer.

Best example: Chronic Myeloid Leukemia (CML)

This is a type of blood cancer. In the past, when CML developed, it was a fatal disease. But after the discovery of TKIs, CML has now become a chronic disease that can be controlled with medications like diabetes and high blood pressure.

In the cells in the bone marrow of CML patients, the Tyrosine kinase enzyme we mentioned is abnormally formed, and its switch is permanently 'on'. So the bone marrow produces white blood cells without control. This prevents the production of healthy red blood cells, white blood cells, and platelets. TKIs, such as Imatinib (Gleevec®) , target that abnormal enzyme and turn its 'on' switch 'off'. This is a major revolution in the history of cancer treatment.

What types of cancer are TKIs used for?

This targeted therapy is now being used for many types of cancer. It doesn't work for all cancers. This is because not all cancers have the 'turned on' Tyrosine kinase. Doctors take a biopsy of the cancer cells and see if they have this targetable molecule. Only if it does, will they give this medicine.

Below are some of the main types of cancer treated with TKIs.

Currently, the US FDA has approved more than 50 TKIs to treat a variety of cancers. The first approved drug, Imatinib (Gleevec®), is used to treat 7 types of cancer.

How do I get this treatment? How long does it take?

This is another great convenience of this treatment. Most TKIs come in pill or liquid form. So you don't have to stay in the hospital and have the medication injected through a saline solution. You just have to take one or two pills at the same time every day from home.

How long you need to take treatment depends on the type of cancer you have, the stage of the disease, and how your body responds to the medication. For example, if you have CML, you may need to take the medication for the rest of your life. For other types of cancer, your doctor may decide to stop the medication once the cancer is under control.

Let's also be aware of side effects.

Because TKIs are targeted therapies, they generally have fewer side effects than chemotherapy. This is because they cause minimal damage to healthy cells. But it is not possible to say that they have "no side effects at all." This is because the molecule they target, called Tyrosine kinase, is not only present in cancer cells, but also in small amounts in some healthy cells. So those cells may also be affected.

Side effects vary from person to person and also depend on the TKI drug used.

Common side effects:

• Fatigue: This is a common condition that many people experience.
• Diarrhea: Can be caused by damage to the cells in the intestines.
• Nausea and Vomiting: Some people may experience this condition.
• Skin Rashes: Skin rashes, dryness, and itching are common.
• Appetite and weight changes: Some people lose weight, while others may gain weight due to bloating.
• Fever

Possible serious side effects:

Some TKIs can cause side effects on the heart, liver, or lungs. They can also cause serious, even life-threatening skin conditions, such as Stevens-Johnson syndrome , which affects the skin. But these are very rare. High blood pressure (hypertension) is another concern.

What can I do to make this treatment easier for me?

Cancer treatment can be a challenging time, both physically and mentally. There are a few things you can do to make this time a little easier.

1. Rest: Fatigue is a major side effect. So get as much sleep as possible, take some rest during the day, and listen to your body.

2. Nutrition: Eating can be difficult due to things like loss of appetite and nausea. Try to eat small amounts several times a day. Drink plenty of fluids like water, fruit juice, porridge, and soup. If you are losing weight or gaining weight unnecessarily, it is very important to seek advice from a nutritionist.

3. Side effect management: If you have diarrhea, eat things like oil, less spicy, steamed vegetables, rice, and bananas. Drinking beverages like Jeevani is very good. If you get a skin rash, use a soap-free, unscented moisturizer. Talk to your doctor about this and get the right medication.

4. Get organized: Keep a diary of your symptoms and side effects. Show it to your doctor when you see him. Remember to take your medications exactly when you need to.

5. Mental health: It is very important to stay mentally strong during this time. Talk to family and friends. Share your problems. If necessary, seek counseling.

6. Palliative Care: This does not mean that the disease is incurable. This is a team of specialists who help you live more comfortably by controlling symptoms such as pain, nausea, and fatigue that come with cancer treatment. You can also talk to your doctor about this service.

What are the risks of this treatment?

Although TKIs work well for many cancers, sometimes problems can arise over time. The main one is the development of resistance .

Simply put, cancer cells are very cunning cells. When given the same drug over time, they can mutate to become resistant to that drug. Just like bacteria become resistant to antibiotics. When that happens, a TKI drug that worked well at first may no longer work.

But it's not the end of the world. Because scientists know this, there are now "second-generation" and "third-generation" TKIs that can be given when resistance develops. So if one drug doesn't work, your doctor may switch you to a different TKI.