Immunotherapy for Cancer
Helping Your Immune System Fight Cancer
What Is Immunotherapy?
Immunotherapy is a type of cancer treatment that helps your immune system (your body’s natural defense) fight cancer.
Unlike chemotherapy or radiation, which directly attack the cancer, immunotherapy trains or boosts your immune system so it can recognize and destroy cancer cells—just like it would attack viruses or bacteria.
How Does It Work?
Your immune system can normally spot and kill abnormal cells. But cancer is tricky—it can hide from the immune system or shut it down.
Immunotherapy works by removing those “invisibility cloaks” or “brakes” so your immune system can see and attack the cancer again.
Main Types of Immunotherapy
| Type | What It Does | Example Drugs |
|---|---|---|
| Immune Checkpoint Inhibitors | Take the “brakes” off immune cells so they can attack cancer | Keytruda (pembrolizumab), Opdivo (nivolumab) |
| CAR T-cell Therapy | Changes your immune cells to better hunt down cancer | Used in blood cancers like leukemia |
| Cancer Vaccines | Trains your immune system to attack cancer cells | Sipuleucel-T for prostate cancer |
| Monoclonal Antibodies | Attach to cancer cells and flag them for destruction | Herceptin (trastuzumab), Rituxan (rituximab) |
| Cytokine Therapy | Uses proteins to boost your immune system | Interleukin-2 (IL-2), Interferon-alpha |
Immune Checkpoint Inhibitors (The Game-Changer)
These drugs are a breakthrough. They remove the “stop signs” on immune cells that prevent them from attacking cancer. They’re approved for many cancers like:
- Melanoma (skin cancer)
- Lung cancer
- Kidney cancer
- Bladder cancer
- Cancers with certain genetic markers (like MSI-H)
Common Checkpoint Drugs:
- Keytruda (pembrolizumab)
- Opdivo (nivolumab)
- Yervoy (ipilimumab)
- Tecentriq (atezolizumab)
- Imfinzi (durvalumab)
How Do Doctors Know If It Will Work?
Doctors test for biomarkers, which are signs in your tumor that may predict how well immunotherapy will work.
| Biomarker | What It Means |
|---|---|
| PD-L1 | Higher levels may mean better response to certain drugs |
| MSI-High / dMMR | Often respond very well to immunotherapy |
| TMB (Tumor Mutational Burden) | More mutations = better chance of response |
| TILs (Tumor-infiltrating lymphocytes) | More immune cells in the tumor = stronger response |
Challenges to Know About
- Side effects (called immune-related): Can include inflammation in the gut, lungs, or liver
- Not everyone responds to immunotherapy
- Some cancers are called “cold tumors” (no immune activity)—immunotherapy might not work
- Cost can be high and may need special testing beforehand
Real Success Stories
- Melanoma: Some patients now live years longer thanks to immunotherapy
- Lung cancer: Keytruda is a first-line treatment for many patients with high PD-L1
- MSI-High cancers: The FDA approved immunotherapy for any tumor with this marker—no matter where it is in the body
Talk to Your Doctor About:
- Whether immunotherapy is right for your cancer
- If biomarker testing is needed first
- Possible side effects and how to manage them
- If there’s a clinical trial you may qualify for
Final Thought
Immunotherapy helps your body fight cancer in a natural and often very powerful way. It doesn’t work for everyone, but for some, it has been life-changing.
