What is immunotherapy?

Your immune system helps detect and destroy abnormal cells in your body, including cancer cells. Sometimes, though, cancer cells can avoid detection, which allows them to keep growing.

Immunotherapy is a type of cancer treatment that helps your body's own immune system fight cancer by training it to better recognize and attack cancer cells.

Immunotherapy can be given in different ways, including:

• Through a vein (IV infusion)
• By mouth, as a pill or capsule
• On the skin, as a topical cream
• Directly into the bladder (intravesical) for certain types of cancer

Treatment schedules for immunotherapy can vary depending on the type of cancer being treated, the stage of cancer, the type of immunotherapy, and how well the treatment is working. Some immunotherapy treatments may be given every few weeks in cycles, while others may be given as a one-time treatment, like CAR-T cell therapy. Your care team will work with you to determine the appropriate treatment length.

There are several types of immunotherapies. Here are a few you may hear about:

• Checkpoint inhibitors: Immune system cells have proteins that act as "checkpoints," which help prevent them from attacking healthy cells. Some cancer cells use these checkpoints to avoid being detected. Checkpoint inhibitors block this process, allowing the immune system to recognize and attack cancer cells. This is like taking the brakes off your immune system so it can detect and destroy cancer cells more effectively.
• CAR-T therapy: This approach starts by collecting a blood sample and separating out certain immune cells called T cells. In a lab, these cells are modified so they can better recognize cancer cells and then are multiplied before being reintroduced to your body. Once added, they help your immune system better find and fight cancer cells. CAR-T therapy is most often used to treat blood cancers.
• Immune-stimulating therapies: This approach works by indirectly activating parts of your immune system to strengthen its response to cancer cells.

Because immunotherapy increases your immune system's activity, it can sometimes cause your immune system to affect healthy tissues or trigger broader inflammation. This can lead to side effects such as:

• Flu-like symptoms, such as fever or fatigue
• Heart palpitations
• Sinus congestion
• Nausea or vomiting
• Diarrhea
• Colitis
• Cytokine release syndrome: a reaction causing widespread inflammation in the body

Experiences can vary widely, from mild to severe. Your healthcare provider will monitor side effects throughout your treatment plan and help you manage any you may be experiencing.

What is targeted therapy?

Targeted therapy is designed to focus on specific molecules that help cancer cells grow and survive. Each cancer has a unique combination of these molecules, including genes and proteins, known as biomarkers. By acting on specific features of cancer cells, targeted therapy is often described as a form of "precision medicine."

To guide treatment decisions, healthcare providers first need to identify whether specific biomarkers are present in your cancer. This is done through a process called "biomarker testing." Knowing which biomarkers are involved helps determine whether a targeted therapy may be effective for you and can also help guide your care team away from treatments that may be less likely to work. This can make treatment more precise and personalized.

Targeted therapies are designed to act on these biomarkers, using drugs that interact with specific features of cancer cells. These therapies can work in different ways depending on where the target is found, which may be on or inside the cancer cell. Read What are cancer biomarkers and what is biomarker testing? to learn more.

Targeted therapies generally fall into two categories:

• Small-molecule drugs, which are often taken as an oral pill or capsule. These are small enough to get inside cells and act on targets within them.
• Monoclonal antibodies, which are usually given through a vein by an IV infusion. They can work by marking cancer cells for the immune system to recognize and destroy, stopping cancer cells from growing, or causing them to be destroyed directly.

Targeted therapy may be taken for different lengths of time, depending on how it fits into your overall treatment plan and how well you're responding to it.

Because some healthy cells can carry the same biomarkers that targeted therapies act on, this can affect normal cells as well, which may lead to side effects.

Side effects from targeted therapy can vary depending on the individual and can range in severity. These may include:

• Diarrhea
• Liver-related problems
• High blood pressure
• Fatigue
• Issues with blood clotting

Not everyone experiences these side effects, and your healthcare provider can help with strategies if side effects occur.