Targeted Therapy vs. Immunotherapy for Cancer

If you’ve been diagnosed with cancer, one of your first questions is probably: “What are my treatment options?” Your cancer care team may recommend well-known options such as surgery, chemotherapy, and radiation. They also may discuss immunotherapy or targeted therapy, new types of treatment that are very effective against certain types of cancer.

“We are seeing new and evolving treatments to treat cancer that we didn't have before. They can give you a better quality of life, a longer life, and in some cases, a cure,” says Susan Saintiche, RN, a nurse practice specialist in the Cellular Immunotherapy Program at Mass General Cancer Center. “The future is personalization of health care. Both of these treatments are individualized care because they use certain unique characteristics of a person’s cancer in order to fight the disease.” 

The advanced treatments work in different ways, explain Saintiche and Sara Cobb, RN, a Mass General Cancer Center nurse practice specialist and clinical nurse manager of the Cellular Immunotherapy Program.

What is immunotherapy?

Immunotherapy is a group of treatments that can help your own immune system find and fight cancer cells. The immune system exists to protect you from infections and diseases. But sometimes cancer cells have special characteristics that help them resist the immune system.

How does immunotherapy work? It can help your body produce more immune cells or stronger immune cells. It also can help your immune system locate cancer cells that are trying to hide.

“When you get sick, your body recognizes the virus or the bacteria, and fights against it. It's the same with cancer, your body recognizes the abnormal cells,” Saintiche says. “But cancer creates a toxic environment for your immune cells. They get kind of chained down and can’t do their job. Immunotherapy helps boost cancer-killing cells so they can fight the cancer.”

Immunotherapy can improve cancer survival, often with fewer side effects than other types of cancer treatment, such as chemotherapy. And it can have long-lasting effects, preventing cancer from spreading or coming back. “In some cases, it creates a durable response for you to keep the cancer at bay. In other cases, it’s a cure that lasts for the rest of a person’s life,” Cobb says.

Types of cancer immunotherapy

There are several types of immunotherapy that work in different ways:

• Checkpoint inhibitors: Immune checkpoints prevent immune responses from being so strong that they harm healthy cells, kind of like brakes on a car. Cancer cells can learn to use these checkpoints to stop the immune system from attacking them. Checkpoint inhibitors block the checkpoints, allowing immune cells to respond to the cancer cells.
• Chimeric antigen receptor (CAR) T-cell therapy: This type of immunotherapy is also known as CAR T-cell therapy. It involves removing some of your own immune cells (T cells), genetically modifying them to find and kill cancer cells, then putting them back into your body.
• Cytokine treatments: Cytokines are proteins that signal the immune system to do its job. Some cytokines can be made in a laboratory and then given as cancer treatment. 
• Immunomodulators: Immunomodulatory drugs help boost your immune system in different ways. For example, they can help your system make more white blood cells to fight cancer. Or they can stop tumors from creating new blood vessels, which they need in order to grow. 
• Monoclonal antibodies: The immune system produces antibodies to attack harmful things like germs and cancerous cells. Monoclonal antibodies are proteins that scientists can manufacture to act like natural human antibodies. A monoclonal antibody may be considered either an immunotherapy or a targeted therapy, depending on how it’s used. In immunotherapy, monoclonal antibodies mark cancer cells so the immune system can see them.
• Vaccines: Most people are familiar with vaccines that help prevent infections. But there are also vaccines to help prevent or treat certain types of cancers.

What is targeted cancer therapy?

Some cancer cells have certain proteins that help them grow. Targeted therapy interferes with those proteins. This is different than chemotherapy, which aims to destroy cancer cells. And it is different than immunotherapy, which uses the immune system to fight cancer.

How does targeted therapy work? It can:

• Interrupt the signals cancer cells use to communicate, grow, and divide
• Stop tumors from forming new blood vessels, which they need to grow, or destroy a tumor’s existing blood vessels
• Deliver toxins to the cancer cells, causing them to die
• Starve cancer cells of hormones that some tumors need to grow (for example, breast cancer and prostate cancer)

Targeted therapy causes less harm to normal cells than other treatments can, which may mean fewer side effects.

Types of targeted therapy

There are two main types of targeted therapies: small-molecule drugs and monoclonal antibodies.

• Angiogenesis inhibitors: These small molecule drugs block a tumor from forming new blood vessels.
• Monoclonal antibodies: When monoclonal antibodies are used as targeted therapy, they attach to specific targets on cancer cells. Once they attach, they can interfere with cancer growth, kill the cells, or make the cells self-destruct.
• Proteasome inhibitors: This type of treatment disrupts cells’ functions, and the cancer cells die.
• Signal transduction inhibitors: These disrupt the signals that cancer cells use to communicate and spread.

Side effects of immunotherapy and targeted therapy

Both types of treatments are generally well tolerated, Cobb and Saintiche say. However, they can cause side effects and, rarely, serious complications. Your team monitors you closely to help you manage any side effects or complications and to determine whether your treatment is working.

Immunotherapy and targeted therapy may cause:

• Flu-like symptoms, such as fatigue, fever, chills, and body aches
• Heart palpitations or changes in blood pressure
• Pain, soreness, or swelling at the injection site
• Skin reactions such as rash, dryness, itchiness, redness, or sensitivity to light
• Gastrointestinal symptoms, including nausea, vomiting, and diarrhea

Rare but serious complications include effects on the brain and nervous system, immune system, heart, and lungs.

Which cancer treatment should I choose?

No two cancers are the same. Your cancer care team will consider several things to develop an individual cancer treatment plan. This may include immunotherapy, targeted therapy, surgery, chemotherapy, and radiation — or a combination.

Your cancer care team may recommend immunotherapy or targeted therapy based on:

• Cancer type (for example, lung cancer, breast cancer)
• How advanced the cancer is (known as the stage)
• Treatment, or treatments, you’ve already had
• Test results showing whether the cancer has certain characteristics (often called biomarkers) that would make these treatments effective

Saintiche and Cobb emphasize that the type of cancer treatment best for you is the one developed along with you by your treatment team as part of coordinated care.

“Trust in your team,” Saintiche says. “They know what treatment will be best for you and your cancer. Whether it’s targeted therapy or immunotherapy, it has to work for you and your specific type of cancer.”