Chemotherapy, Immunotherapy, Targeted Therapy. What’s the difference? | Cancer-Champions | Health Care Consulting

Scientists have been searching for the most effective ways to treat cancer for centuries. Two big milestones in the way cancer is treated occurred in the early 1900s with the development of radiation therapy, and the second in the 1940s with the introduction of chemotherapy.

In 2003, the completion of the Human Genome Project marked a dramatic shift in the understanding of cancer and other diseases. Researchers mapped the entire human genetic code and discovered that every human cell is made up of 20,000 to 30,000 genes.   As a result the past decade has been one of exploration into novel approaches to treating cancer and new drug discovery.

Today there are a variety of treatments available. What are the differences?


Our cells go through different phases (cell cycle) as they form new cells. Cancer cells form new cells more rapidly than normal cells.   Chemotherapy drugs affect cells at specific stages of a cell’s cycle, however they do not differentiate between cancerous cells and healthy cells. Many healthy cells also have a rapid cell cycle, such as those in the gastrointestinal tract and hair follicles and thus are more susceptible to the effects of chemotherapy resulting in nausea and hair loss during treatment. There are a multitude of chemotherapy agents that may be used alone or in combination as well as with other cancer treatment.


Immunotherapy cancer treatments use the body’s immune system to fight cancer cells by stimulating the immune system. Immunotherapy includes treatments that work with the immune system in different ways and works better for some types of cancer than for others.   Immunotherapy may be used by itself or with other types of treatment. The main types of immunotherapy being used to treat cancer include:

  • Monoclonal Antibodies
  • Immune Checkpoint inhibitors
  • Cancer vaccines

Targeted Therapy

Cancer researchers have discovered some of the differences within cancer cells that enable them to thrive. Targeted therapy refers to treatment with drugs that have been developed to “target” these differences within the cell. Unlike chemotherapy, targeted therapy drugs alter the inner workings of the cell focusing on the part of the cancer cell that makes it different from the normal, healthy cell.   Because they leave the healthy cells alone the side effects of targeted therapies are different from standard chemotherapy treatments.

Targeted therapy works by one of the following:

  • Arresting the development of new blood vessels that feed the cancer cell
  • Triggering the immune system to attack the cancer cell
  • Changing proteins within the cancer cell
  • Blocking or turning off signals telling the cancer cell to grow or divide
  • Carrying toxins directly to the cancer cell

The specificity of cancer cells precludes a standard treatment for all cancer types and your treatment may or may not include one of the types of treatment listed above. It is important to understand what type of cancer you have been diagnosed with and the testing available to see if you may benefit from one of the newer approaches to treatment.

If you need help preparing for an appointment with an oncologist, look in the sidebar to download our 20 questions to ask at your next appointment.