Cancer treatment has changed significantly over the past few decades. Alongside surgery, chemotherapy and radiation therapy, immunotherapy for cancer has become an important treatment option for certain patients.
But what exactly is immunotherapy? How does it work? And can every cancer patient benefit from it?
The short answer is no—immunotherapy is not suitable for every cancer or every patient. Its effectiveness depends on factors such as the type and stage of cancer, specific characteristics of the tumor, biomarkers, previous treatments and the patient’s overall health.
What Is Immunotherapy for Cancer?
Cancer immunotherapy is a type of treatment that helps the body’s immune system recognize and attack cancer cells.
Normally, the immune system protects the body from infections and abnormal cells. However, cancer cells can develop ways to avoid immune-system detection or suppress immune responses.
Immunotherapy aims to overcome some of these mechanisms and help immune cells fight the cancer.
Unlike chemotherapy, which directly attacks rapidly dividing cells, many forms of immunotherapy work by changing or strengthening the immune response against cancer.
How Does Immunotherapy Work?
Your immune system contains specialized cells, including T cells, that can recognize abnormal cells.
Cancer cells may use biological “brakes” to prevent T cells from attacking them. These are known as immune checkpoints.
Some immunotherapy medicines called immune checkpoint inhibitors block these checkpoint signals.
For example, PD-1 and PD-L1 are proteins involved in one of these immune-regulating pathways. Blocking this interaction can allow T cells to remain active against cancer cells. Other checkpoint inhibitors target CTLA-4.
In simple terms:
Cancer cell → suppresses immune response → immunotherapy blocks the suppression → immune cells can attack cancer cells.
However, the immune response is complex, and not every tumor responds to checkpoint inhibition.
What Are the Different Types of Cancer Immunotherapy?
Immunotherapy is not one single treatment. It includes several approaches.
1. Immune Checkpoint Inhibitors
These medicines block checkpoint proteins that can prevent T cells from attacking cancer.
Common targets include:
- PD-1
- PD-L1
- CTLA-4
Checkpoint inhibitors are used for selected patients with several different cancer types.
2. T-Cell Transfer Therapy
This approach uses the patient’s own immune cells.
Doctors collect certain T cells, select or modify cells with cancer-fighting activity, grow them in the laboratory, and then return them to the patient’s body.
CAR T-cell therapy is one form of T-cell transfer therapy. It modifies T cells so they can recognize specific targets on cancer cells.
CAR T-cell therapies are established for several blood cancers, while their use in many solid tumors remains an area of research.
3. Monoclonal Antibodies
Monoclonal antibodies are laboratory-produced proteins designed to recognize specific targets.
Some monoclonal antibodies can help the immune system identify and destroy cancer cells, while others work through targeted mechanisms.
4. Immune System Modulators
Some treatments stimulate or modify the immune response.
Examples include certain cytokines, immune-modulating medicines and BCG, which can be administered directly into the bladder for selected cases of bladder cancer.
5. Cancer Treatment Vaccines
Cancer treatment vaccines are different from vaccines designed to prevent infections.
They are intended to help the immune system recognize and attack cancer cells in people who already have cancer.
For example, sipuleucel-T is an approved treatment vaccine used for certain men with advanced prostate cancer.
Which Cancers Can Be Treated With Immunotherapy?
Immunotherapy is used for selected patients with several types of cancer.
Depending on the specific medicine and clinical situation, immunotherapy may be used in cancers such as:
- Melanoma
- Lung cancer
- Kidney cancer
- Bladder cancer
- Head and neck cancers
- Liver cancer
- Colorectal cancer
- Stomach and oesophageal cancers
- Certain breast cancers
- Some blood cancers
- Other selected cancers
However, simply having one of these cancer types does not automatically mean immunotherapy is appropriate.
The treatment decision depends on the specific cancer, its stage, molecular characteristics, previous treatments and other clinical factors.
Who Can Benefit From Immunotherapy?
The most important question is not simply “Do I have cancer?”
It is:
“Does my particular cancer have characteristics that make immunotherapy likely to help?”
Doctors may consider factors such as:
Cancer Type
Some cancers are more responsive to immunotherapy than others.
Cancer Stage
Immunotherapy may be used at different stages depending on the cancer and treatment plan. In some situations, it may be used after surgery, while in others it may be used for advanced or metastatic disease.
Biomarkers
Certain biomarkers can help identify patients who may be more likely to respond to specific immunotherapies.
Examples include:
- PD-L1 expression
- Tumor mutational burden (TMB)
- Microsatellite instability (MSI)
- Mismatch repair deficiency (dMMR)
Biomarker testing can help doctors determine whether certain immunotherapies may be appropriate. However, biomarkers do not perfectly predict response in every patient.
Previous Treatments
The patient’s previous surgery, chemotherapy, radiation therapy, targeted therapy or other treatments may influence the treatment plan.
Overall Health
Doctors also consider a patient’s general health, other medical conditions, medications and ability to tolerate treatment.
What Is PD-L1 and Why Does It Matter?
PD-L1 is a protein that can be present on cancer cells and other cells in the tumor environment.
When PD-L1 interacts with PD-1 on T cells, it can send a signal that reduces T-cell activity.
Some immunotherapy medicines block this pathway and may restore T-cell activity against cancer cells.
A laboratory test can sometimes measure PD-L1 expression in tumor tissue.
However, PD-L1 is not a simple yes-or-no predictor of whether immunotherapy will work. Some patients with low or absent PD-L1 expression may still benefit from particular treatments, while not every patient with high expression will respond.
What Is MSI or dMMR?
Another important group of biomarkers involves microsatellite instability (MSI) and mismatch repair deficiency (dMMR).
Certain cancers with these characteristics can be particularly responsive to immune checkpoint inhibitors.
This is one reason biomarker testing can be important when doctors are considering immunotherapy.
Your oncologist can determine whether testing for these or other biomarkers is appropriate for your cancer.
Is Immunotherapy the Same as Chemotherapy?
No.
Although both are cancer treatments, they work differently.
| Immunotherapy | Chemotherapy |
|---|---|
| Helps the immune system attack cancer | Directly attacks rapidly dividing cells |
| Often works through immune pathways | Uses cytotoxic medicines |
| Response can vary according to tumor biology | Effect depends on cancer type and drug |
| Can cause immune-related side effects | Can cause effects such as nausea, fatigue and low blood counts |
| May produce long-lasting responses in some patients | Treatment response varies by cancer and regimen |
Some patients may receive immunotherapy together with chemotherapy, radiation, targeted therapy or surgery, depending on their cancer and treatment plan.
What Are the Side Effects of Immunotherapy?
Immunotherapy can cause side effects because activating the immune system may sometimes cause it to attack healthy tissues.
Possible side effects include:
- Fatigue
- Skin rash
- Itching
- Diarrhea
- Nausea
- Fever
- Joint or muscle pain
- Thyroid or other hormone problems
- Liver inflammation
- Lung inflammation
- Colon inflammation
In some cases, immune-related inflammation can affect organs such as the lungs, liver, intestines, heart or nervous system.
Some reactions can be serious or potentially life-threatening, although severe reactions are not experienced by everyone.
When Should You Contact Your Cancer Care Team?
If you are receiving immunotherapy, do not assume a new symptom is unrelated to treatment.
Contact your healthcare team if you develop symptoms such as:
- Persistent diarrhea
- Severe abdominal pain
- New or worsening cough
- Difficulty breathing
- Severe skin rash
- Yellowing of the eyes or skin
- Significant weakness
- Persistent fever
- Severe headache or confusion
- Unusual changes in urination
- Significant changes in vision
Early recognition and treatment of immune-related side effects can be important.
Does Immunotherapy Work for Everyone?
No.
Some patients experience a strong response, while others have little or no response.
In some patients, responses can be long-lasting. Researchers are continuing to study why some cancers respond particularly well while others resist immunotherapy.
This is why doctors may use pathology, imaging, biomarker testing and the patient’s overall clinical information when deciding whether immunotherapy is appropriate.
Can Immunotherapy Cure Cancer?
Immunotherapy can produce long-lasting responses in some cancers and some patients.
However, it would be inaccurate to say that immunotherapy cures every cancer.
Whether treatment can eliminate the cancer or control it for a long period depends on factors including:
- Cancer type
- Cancer stage
- Tumor biology
- Biomarkers
- Previous treatments
- Response to treatment
- Overall health
Your oncology team can explain the expected goals of treatment in your specific situation.
What Happens During Immunotherapy Treatment?
Many immunotherapy medicines are administered through an intravenous infusion, although some forms are given in other ways.
Treatment schedules vary. Some patients receive treatment every few weeks, while others receive different schedules depending on the drug and cancer type.
During treatment, your medical team may monitor:
- Symptoms
- Blood tests
- Organ function
- Tumor markers when appropriate
- Imaging scans
- Overall response to treatment
Treatment may continue for a defined period or be adjusted depending on response and side effects.
Is Immunotherapy Right for You?
There is no universal answer.
If you or someone you know has been diagnosed with cancer, ask the oncology team:
- What type and stage of cancer do I have?
- Is immunotherapy an option for my cancer?
- Do I need biomarker testing?
- What do my PD-L1, MSI, dMMR or other test results mean?
- Is immunotherapy being used alone or with other treatments?
- What side effects should I watch for?
- How will we know whether the treatment is working?
- What are the goals of treatment?
These questions can help you understand why a particular treatment is being recommended.
The Future of Cancer Immunotherapy
Cancer immunotherapy continues to evolve.
Researchers are investigating new checkpoint inhibitors, personalized immune treatments, engineered T-cell therapies, cancer vaccines and combinations of immunotherapy with other treatments.
The goal is to identify which patients are most likely to benefit while reducing unnecessary treatment and treatment-related complications.
Conclusion
Immunotherapy for cancer works by helping the immune system recognize and attack cancer cells. One of the most widely used approaches is immune checkpoint inhibition, which can remove signals that suppress T-cell activity. Other approaches include T-cell transfer therapy, monoclonal antibodies, immune-system modulators and cancer treatment vaccines.
However, immunotherapy is not suitable for every cancer patient. Cancer type, stage, tumor biology, biomarkers, previous treatment and overall health all influence whether it may be appropriate.
If you have been diagnosed with cancer, discuss your treatment options with a qualified oncologist and ask whether biomarker testing and immunotherapy should be considered as part of your individual treatment plan.
Frequently Asked Questions
1. What is immunotherapy for cancer?
Immunotherapy is a cancer treatment that helps the immune system recognize and attack cancer cells.
2. How does immunotherapy work?
Some immunotherapies block immune checkpoints such as PD-1, PD-L1 or CTLA-4, allowing T cells to remain active against cancer cells. Other types modify or stimulate immune cells in different ways.
3. Which cancers respond to immunotherapy?
Immunotherapy is used for selected patients with several cancers, including certain lung, kidney, bladder, melanoma, liver, colorectal and blood cancers. The appropriate treatment depends on the individual cancer.
4. What tests determine whether immunotherapy may work?
Depending on the cancer, doctors may evaluate biomarkers such as PD-L1, MSI, dMMR or tumor mutational burden. Biomarker testing can help guide treatment decisions.
5. Does immunotherapy have side effects?
Yes. Because immunotherapy affects the immune system, it can cause inflammation in healthy tissues. Side effects can range from mild skin reactions to serious inflammation affecting organs.
6. Is immunotherapy better than chemotherapy?
Neither treatment is universally better. The appropriate treatment depends on the type and stage of cancer and the individual patient’s tumor characteristics and health.
7. Can immunotherapy cure cancer?
Some patients can experience long-lasting responses, but immunotherapy does not cure every cancer. Treatment goals and expected outcomes vary between patients.
Medical Disclaimer:
This article is for general educational purposes and does not replace professional medical advice, diagnosis or treatment. Immunotherapy medicines, approved indications and treatment protocols can vary by cancer type, country and individual patient. Always discuss treatment decisions with a qualified oncology team.