Targeted Therapy

Targeted therapy is one of the major advances in cancer treatment. It is a more focused treatment approach that inhibits specific features of cancer cells that help them grow or spread. 

Unlike chemotherapy and radiation, which can hurt healthy cells as part of their cancer treatment, targeted cancer therapy is designed to make it harder for cancer cells to survive and multiply without harming healthy cells as much. 

The goal of targeted therapy is to focus on the weaknesses of cancer cells while protecting healthy cells. Health care providers match this personalized treatment to the type of cancer you have.

How does targeted therapy work?

Targeted therapy stops processes that help cancer cells grow and spread. It focuses on specific molecules (like proteins) inside cancer cells or on their surface and blocks the biological processes that help cancer thrive.

It can:

• Block cancer growth signals: Some cancers rely on specific signals to grow and multiply. Targeted therapy can interrupt these signals, so the tumor can’t grow. For example, certain breast cancer cells produce too much of a protein called HER2. Drugs that target HER2 can block the signal.
• Cut off a tumor’s blood supply: Tumors need blood vessels to grow and spread. Targeted therapies called angiogenesis inhibitors stop tumors from developing new blood vessels, which starves the cancer cells of oxygen and nutrients.
• Boost your immune system’s ability to defend against cancer: Some targeted therapies remove the shield that cancer cells use to hide from immune system defenses. This helps your immune system spot and destroy cancer cells. 
• Deliver toxins to cancer cells: Some targeted therapies attach to cancer cells and deliver cancer-destroying substances inside them without causing much damage to healthy cells.

To find out if targeted therapy is the right option for you, health care providers analyze the tumor’s molecules and genes. Testing before starting treatment is important because not all cancers have the same targets.

Types of targeted therapy

There are several kinds of targeted therapy. Different types of cancer need different treatments:

• Small molecule drugs: These drugs are small enough to enter the cancer cells and stop activities that make them grow. They are often taken as pills or capsules, and may be used to treat lung cancer, leukemia or melanoma.
• Monoclonal antibodies: These proteins are made in a lab. Monoclonal means coming from one clone. Experts make copies of a special cell to create this treatment. The proteins stick to targets on the outside of cancer cells and can either stop them from growing or flag them so the immune system can destroy them. They may also carry treatment like radiation or chemotherapy directly to cancer cells. 
• Hormone therapies: Hormones are chemicals your body needs, but some cancers rely on your hormones to survive. These therapies stop or lower hormone levels to keep cancer cells from growing. They may be used to treat breast, prostate and uterine cancer. 
• Angiogenesis inhibitors: These drugs stop tumors from forming new blood vessels. Tumors can’t grow or spread without the nutrients they get from blood.
• Proteasome inhibitors: These drugs stop cancer cells from breaking down waste. When they can’t break down waste, they die. Proteasome inhibitors are often used to treat multiple myeloma.

Approved targeted therapy drugs treat many different types of cancers. Providers recommend them based on the proteins, genes or cell functions found in the cancer.

Some common types of targeted therapy drugs include: 

• Breast cancer drugs: They often focus on proteins like HER2, which are produced by certain breast cancers.
• Lung cancer drugs: They aim at genetic mutations like EGFR, which help cells communicate or grow.
• Leukemia drugs: They block key enzymes, which are substances that speed up chemical reactions that cancer cells need to grow.

What to expect from targeted therapy

If your health care provider recommends targeted therapy to treat your cancer, it may be given as:

• Pills or capsules: Many targeted therapy drugs can be taken at home by mouth.
• IV infusions: Some medications need to be given through an intravenous (IV) drip directly into a vein, at a hospital or clinic.

The number of doses of targeted therapy you’ll need depends on:

• The type of cancer being treated
• Your body’s response to the treatment
• Possible side effects

Your doctor will monitor your progress and watch how the cancer responds to the treatment with blood tests and scans.

Side effects of targeted therapy

Targeted therapy is more precise than chemotherapy, but these drugs can still cause side effects. They vary depending on the drug used. 

Common side effects include:

• Skin problems (rash, dry skin or itching)
• Diarrhea
• High blood pressure
• Fatigue
• Liver problems
• Increased risk of infections

Your health care provider will help you manage any side effects with medication or changes to your treatment plan.

Who can benefit from targeted therapy?

Not all types of cancer respond to targeted therapy drugs. Your health care provider may recommend it if your tumor has certain proteins or mutations. 

Testing for genetic mutations or changes in cancer cells is important to find the best treatment for your type of cancer. In some cancers, like chronic myelogenous leukemia (CML), almost every person with the disease has a mutation that can be treated with targeted therapy.

Targeted therapy is used to treat different cancers, including certain types of:

• Breast cancer
• Lung cancer
• Colorectal cancer
• Leukemia and lymphoma 
• Melanoma
• Kidney cancer

Targeted therapy may also be an option for advanced cancer that hasn’t improved with other treatments.

Targeted therapy and clinical trials

Clinical trials for cancer are studies where people help test new treatments. If current treatments don’t work for you, you may qualify for trials of experimental targeted therapy drugs.

Clinical trials may give you access to cutting-edge treatments, plus they also contribute to research that helps others. Your care team will help you find trials that match your type of cancer and your personal situation. 

Combining targeted therapy with other treatments

Targeted therapy is often used with other cancer treatment to improve results:

• Chemotherapy: Targeted therapy may make cancer cells more sensitive to chemo drugs.
• Radiation therapy: Targeted therapy may help radiation work better.
• Immunotherapy: Some immune system therapies work better when combined with targeted drugs.
• Theranostics: This newer approach combines diagnosis and therapy. It uses radioactive molecules that both detect and target cancer cells. With it, health care providers can identify tumors and treat them at the same time.

Getting care

If you or someone you know has cancer, talk to your health care provider to see if targeted therapy drugs might help. Testing can show whether these treatments might be effective for the type of cancer you have. 

At Banner MD Anderson Cancer Center, we offer leading-edge care that uses some of the latest tools to create a treatment plan tailored to you. Our advanced treatments and access to clinical trials mean you’ll have a range of tools to use in your journey to overcome cancer. Contact us to explore your options and learn more about your treatment possibilities.