There have been enormous amounts of progress made in the field of cancer treatment in the past decade. For example, there are increasingly breast cancer targeted therapies and other types of therapies for varying types of cancer.
Targeted therapy can be more effective and have fewer side effects than chemotherapy and radiation. In some cases, it might be used along with other more traditional treatments to improve outcomes.
The following are some of the big things to know about targeted therapy as a treatment for cancer.

1. What It Is
Targeted therapy is one type of cancer treatment that often targets proteins that control how cancer cells grow and divide and ultimately spread. Targeted therapy is within the field of precision medicine, and as researchers are learning more about proteins that drive cancer as well as DNA changes, they’re increasingly able to create more effective targeted therapies.
Cancer cells usually have genetic changes that make them distinct from normal, healthy cells. When a cell has certain changes to its genes, it doesn’t function or behave like a normal cell. These genetic changes can, for example, allow a cell to grow and divide rapidly, which would make it a cancer cell.
With that being said, there are a lot of types of cancers, and not all the cells are the same, so researchers can now target certain types of proteins and enzymes that send messages telling a cancer cell to grow and copy itself.
To use targeted therapy, a healthcare provider will usually test for genetic changes to identify what’s responsible for the growth and survival of cancer cells.
2. How It Works
After a healthcare provider knows the genetic mutation that’s turning a healthy cell into one that’s cancerous, they can start to identify parts of the cell to target during treatment.
Monoclonal antibodies are lab-made versions of antibodies. Antibodies are part of the immune system. They’re proteins that will look throughout your body for antigens, which are intruder proteins. Antibodies target the antigens to eliminate intruders.
There are also small-molecule drugs that will attach to specific targets on a cancer cell to prevent it from growing or to kill it.
Specifically, ways targeted therapy can work include:
- Helping the immune system destroy cancer cells by making it easier to find and destroy them. Otherwise, cancer cells can hide from the immune system and evade destruction.
- Some cancer cells have changes in surface proteins that tell them to divide, even if there are signals telling them or not. Some types of targeted therapy will interfere with the proteins to prevent them from telling cells to divide, slowing the uncontrolled growth of cancer cells.
- Tumors may need to form new blood vessels to grow, and this process is known as angiogenesis. Targeted therapy can interfere with the ability of a tumor to create a blood supply.
- Cancer cells have a way of avoiding cell death, whereas healthy cells die when they’re damaged or not needed anymore. Targeted therapies can trigger apoptosis, which is the process of cell death.
- There are types of targeted therapies that block cancer cells from getting certain hormones needed to grow.
3. The Side Effects
While targeted therapy is often less toxic and has fewer side effects than chemotherapy or radiation, some are still possible.
For example, liver problems and diarrhea may occur. Problems with blood clotting, fatigue, mouth sores, and high blood pressure are also examples of possible side effects.
Cancer cells can sometimes become resistant to targeted therapy, and because of that, these therapies might be combined with other cancer treatments.
4. Which Types of Cancer Can Targeted Therapy Help with?
There are more than 80 currently available targeted therapies.
Some of the types of cancers that are most often effectively treated with targeted therapies include blood cancers like leukemia and lymphoma, brain cancers, and bone and soft tissue cancers like sarcomas.
Breast, digestive, head and neck, lung, thyroid, and reproductive system cancers, as well as skin cancers, may also be treated with targeted therapy.
5. Does It Always Work?
Targeted therapy isn’t always effective. It’s challenging to identify a target, and there’s still a lot of learning going on.
Targeted therapy might not work if the tumor doesn’t have a target matching a treatment. Tumors don’t always react the way they’re expected to, and tumor cells can continue to mutate, which may impact effectiveness.
Success rates vary quite a bit depending on cancer and stage, but these are effective treatments for many people.