What Is Targeted Therapy for Cancer Treatment? | UPMC HealthBeat (2024)

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Targeted therapy is a highly precise method of fighting cancer with drugs. This type of treatment targets the proteins that control how cancer cells grow, divide, and spread at the molecular level. Researchers improve treatments targeting these proteins as they learn more about the DNA changes that drive cancer.

Targeted therapy is the foundation of precision medicine — also called personalized medicine. It’s an individualized approach that helps your health care provider find your unique disease type and treat you with the most effective medications for it.

Common Targeted Cancer Therapies

Researchers have found numerous molecular mutations (differences) among certain types of cancer cells that respond well to targeted therapies. Some common targeted therapies for cancer include:

• Angiogenesis inhibitors — which prevent the growth of blood vessels to tumors.
• Apoptosis inducers — which cause controlled apoptosis (cell death) in cancer cells.
• Gene expression modulators — which alter a cell’s genes to make it perform in a certain way.
• Monoclonal antibodies — which bind to the target cell to deliver a toxic substance.
• Signal transduction inhibitors — which interrupt the molecules that help a cell respond to environmental cues (for instance, the message to continue cell division).

How Does Targeted Therapy Work?

Most targeted therapies treat cancer by blocking specific proteins that encourage tumor growth and metastasis (spreading to other areas). It works differently from traditional chemotherapy, which often kills all rapidly dividing cells in the body.

Instead, targeted therapies boost the cancer-destroying powers of the immune system. They search the body for cancer, marking cells so your immune system can find and destroy them.

Targeted therapy can:

• Cause cancer apoptosis (cell death) — Healthy cells die an orderly death when they become damaged or the body no longer needs them. However, cancer cells often don’t. Targeted therapies can activate cancer cell death.
• Choke off hormones the tumor needs to grow — Hormones can cause certain cancers to grow, including some breast and prostate cancers. Hormone therapies can prevent your body from producing certain hormones or your hormones from acting on the cancer cells.
• Distribute cell-killing substances throughout cancer cells — Lab-engineered molecules can alter, improve, mimic, or repair the body’s immune system’s ability to attack unwanted cancer cells.
• Stop the growth of new blood vessels — Tumors need a blood supply to grow. In a process called angiogenesis, tumors send signals to cells to form new blood vessels. Angiogenesis inhibitors are targeted therapies designed to block these signals so blood vessels can’t access blood supply. Without blood supply, the blood vessels usually die, causing the tumor to shrink.
• Stop the proliferation (overgrowth) of cancer cells — Your body constantly makes new cells when it needs to replace old cells. Certain proteins on their surfaces signals cells to divide. Some cancer cells have mutations in the proteins that tell them to divide over and over. Targeted therapies can block the signal to divide, helping to slow the cancer’s uncontrolled growth.

What Are the Types of Targeted Therapies?

Some types of cancer have known targets for certain drugs, but others don’t. In most cases, you’ll need a tumor biopsy and a type of genetic test known as biomarker testing to see if the target is present.

A biopsy involves the removal of a small piece of the tumor. Biopsy carries a small risk, which varies depending on the size and location of the tumor.

If your cancer type is commonly associated with a molecular target, your doctormay suggest targeted therapy. Some targeted therapies use small molecules that can enter cancer cells easily. Other targeted therapies use larger molecules to bind to the surface of the cells.

Small-molecule inhibitors

Small-molecule inhibitors (SMIs) are a type of oral targeted therapy cancer drug that binds to proteins and slows their function. They’re so tiny that they can target a wide range of proteins both inside and outside of cells. SMIs help prevent cancer cell growth, proliferation, and metastasis (spread).

Benefits of SMIs include:

• The bloodstream can easily absorb them.
• Their simple chemical structure makes them easy to make and shelf-stable.
• They are easy to take in capsule or pill form.
• They precisely target a tumor’s molecular irregularities to enable personalized treatments.

Monoclonal antibodies

Also known as therapeutic antibodies, monoclonal antibodies (moAbs) are large-molecule proteins produced in a lab. They can’t fit into the cells, so they attach to specific targets found on cancer cells. MoAbs work as keys that open the cell’s surface enzyme or protein locks.

Benefits of monoclonal antibodies include their ability to do many things to treat cancer, such as:

• Carrying toxins to kill cancer cells.
• Marking cancer cells so the immune system sees them and destroys them.
• Preventing cancer cell growth.
• Programming cells to self-destruct.

MoAbs are usually given in injections or through an intravenous (IV) needle in a vein.

Hormone therapies

Hormones are the body’s natural chemical messengers. They travel throughout the body to regulate the activity and behavior of cells and organs, playing a vital role in functions such as digestion, metabolism, mood, reproduction, and sleep.

However, when hormonal activity increases abnormally, cancer can form. In women, hormones can cause cancers of the endometrium, ovary, andbreast. In men, hormones can causecancer of the prostate.

Hormone therapy uses drugs to alter abnormal actions of certain hormones. Hormone therapy may be recommended:

• If your cancer has spread too far fortumor resection orradiation therapy to cure it.
• If shrinking the tumor would make radiation therapy or surgery more effective.
• To try to prevent another cancer from forming after surgery or radiation.

You can take hormone therapy drugs by mouth or in a shot under the skin or into a muscle. In some cases, hormone therapy can involve surgery or radiation to reduce the amount of hormone production in the body.

Targeted therapy vs. chemotherapy

Targeted therapy is technically chemotherapy because it uses drugs to fight cancer, but it doesn’t work the same way traditional chemo does. Traditional chemotherapy iscytotoxic, meaning it can damage and kill all types of cells — both healthy and cancerous.

Instead of acting on all rapidly dividing cells throughout the body, targeted therapies seek out specific molecular targets on the cells. Rather than killing the cells, these drugs interact with them to block their growth and spread. The medication only affects the cancer cells and largely leaves the healthy cells alone.

Targeted drugs can also block cancer cells from copying or dividing themselves to make new cancer cells. Traditional chemo, on the other hand, kills existing cancer cells.

Is Targeted Therapy Right for Me?

Yourdoctor may order biomarker testing to see if your genetic profile matches one or more known mutations. Targeted therapy drugs search for mutations in cells to disrupt the cancer’s ability to grow.

Biopsy samples are carefully examined to identify the specific molecular targets driving the cancer’s growth. Each mutation or molecular target has a different associated drug. The targets match patients with the most effective treatments for their specific cancers.

The U.S. Food and Drug Administration (FDA) has a list of targeted therapy drugs approved to treat specific cancers. It has approved drugs listed more than once to treat more than one type of cancer.

Benefits of targeted therapy

Targeted therapy is recommended for certain cancers because it:

• Enhances precision by targeting cancer cells without harming healthy nearby tissues.
• Has fewer side effects thanchemotherapy. The most serious problems are diarrhea and liver problems.
• Improves quality of life for patients.

Targeted therapy does have some downsides:

• Cancer cells can become targeted therapy resistant. Doctors often combine targeted therapy with other cancer treatments, such as chemo and radiation, for peak effectiveness.
• Drug development is difficult for some targets due to their structure, function within the cell, or both.