Cancer Immunotherapy: How It Works, Types, Benefits and Side Effects

Cancer treatment has advanced significantly over the years. Alongside surgery, chemotherapy and radiation therapy, cancer immunotherapy has become an important treatment option for certain types of cancer.

Unlike treatments that directly target cancer cells or tumours, immunotherapy helps the body’s immune system recognise and fight cancer. However, it does not work for every patient or every cancer type.

In this guide, we explain how cancer immunotherapy works, the different types available, its potential benefits and the side effects patients should understand.

What Is Cancer Immunotherapy?

Cancer immunotherapy is a type of treatment that helps the immune system identify and attack cancer cells. The immune system normally protects the body against infections and other threats. It can also recognise and destroy some abnormal cells.

However, cancer cells can develop ways to avoid detection or suppress the immune response. Immunotherapy aims to overcome these barriers by strengthening or directing the body’s natural defence mechanisms.

Depending on the cancer type and treatment plan, immunotherapy may be used alone or in combination with other cancer treatments.

How Does Immunotherapy Work Against Cancer?

The immune system contains specialised cells, including T cells, that help identify and destroy abnormal cells. Unfortunately, some cancer cells can hide from these immune cells or activate signals that reduce their ability to attack.

Immunotherapy works in several ways:

• Restoring immune activity: Some medicines block signals that prevent immune cells from attacking cancer.
• Helping the immune system recognise cancer: Certain treatments make cancer cells easier for the immune system to identify.
• Strengthening immune cells: Some therapies enhance or modify immune cells so they can better target cancer.
• Supporting a targeted immune response: Certain treatments use antibodies or other biological agents to direct immune activity towards specific cancer cells.

The exact mechanism depends on the type of immunotherapy prescribed.

What Are the Different Types of Cancer Immunotherapy?

Several forms of immunotherapy are used in cancer care. Each works differently and is suitable for specific clinical situations.

1. Immune Checkpoint Inhibitors

Immune checkpoint inhibitors block proteins that act like brakes on immune cells. By blocking certain checkpoint signals, these medicines can help T cells recognise and attack cancer cells.

They are used for selected patients with cancers such as melanoma, lung cancer, bladder cancer and certain other cancer types. Eligibility may depend on factors such as cancer stage, tumour biomarkers and previous treatment.

2. Monoclonal Antibodies

Monoclonal antibodies are laboratory-made proteins designed to recognise particular targets. Some help the immune system identify cancer cells, while others interfere with signals that cancer cells need to grow.

Their uses vary according to the antibody, its target and the cancer being treated.

3. CAR T-Cell Therapy

CAR T-cell therapy involves collecting a patient’s T cells and modifying them in a laboratory so they can recognise specific targets on cancer cells. The modified cells are then returned to the patient.

This specialised treatment is used for certain blood cancers, including selected leukaemias, lymphomas and multiple myeloma. It requires careful assessment and monitoring at an appropriately equipped treatment centre.

4. Cancer Treatment Vaccines

Cancer treatment vaccines are designed to stimulate an immune response against an existing cancer. They are different from preventive vaccines that protect against infections associated with cancer risk.

Their use is currently limited to particular clinical situations and specific cancer types.

5. Other Immune-Based Treatments

Additional approaches include cytokines, immune-modulating medicines and certain other cell-based treatments. Some are established options for selected conditions, while others remain under investigation.

The most appropriate approach depends on the patient’s diagnosis and the available evidence.

Which Cancers Can Be Treated With Immunotherapy?

Immunotherapy is used for selected patients with several cancer types, including:

• Lung cancer
• Melanoma and certain other skin cancers
• Kidney cancer
• Bladder cancer
• Some breast cancers
• Certain colorectal cancers
• Some lymphomas and other blood cancers
• Selected liver, stomach and head and neck cancers

This does not mean immunotherapy is suitable for every patient with these cancers. Treatment decisions may depend on the cancer’s stage, tumour characteristics, biomarker results, previous treatments and the patient’s general health.

For some cancers, immunotherapy may be recommended as an initial treatment. In other situations, it may be considered after another treatment has stopped working or alongside other therapies.

What Are the Potential Benefits of Immunotherapy?

For appropriately selected patients, immunotherapy can offer important treatment benefits.

A targeted immune response: Some immunotherapies help immune cells recognise particular features of cancer cells.

Long-lasting responses in some patients: Certain immunotherapies can produce durable responses, although the duration and likelihood of benefit vary.

An additional treatment option: Immunotherapy may provide another approach when considering treatment options for specific cancers.

Combination treatment possibilities: Depending on the diagnosis, immunotherapy may be combined or sequenced with chemotherapy, radiation therapy, surgery or targeted medicines.

It is important to understand that these benefits are not guaranteed. Some cancers respond well, while others may respond only partially or not at all.

What Are the Side Effects of Cancer Immunotherapy?

Immunotherapy can cause side effects because activating the immune system may also lead it to attack healthy tissues.

Possible side effects include:

• Fatigue and weakness
• Skin rashes or itching
• Diarrhoea
• Nausea
• Fever or flu-like symptoms
• Inflammation affecting organs such as the lungs, liver, intestines, kidneys or thyroid

Some immune-related side effects can become serious and may develop during treatment or even after treatment has ended.

Patients should contact their healthcare team promptly if they develop new or worsening symptoms. Severe breathing difficulty, chest pain, confusion or other potentially life-threatening symptoms require emergency medical attention.

Doctors monitor patients throughout treatment and may recommend additional tests or medicines to manage complications.

How Do Doctors Decide Whether Immunotherapy Is Suitable?

Choosing immunotherapy requires an individual assessment rather than relying on the cancer type alone.

Doctors may consider:

1. Cancer diagnosis and stage: The type of cancer and how far it has spread.
2. Biomarker testing: Certain cancers require testing for specific tumour features, such as PD-L1 expression or DNA repair abnormalities.
3. Previous treatments: Whether the patient has received chemotherapy, radiation, surgery or other medicines.
4. Overall health: Existing medical conditions, immune system disorders and organ function.
5. Treatment goals: The expected benefits, potential risks and available alternatives.

Not every patient requires the same tests. The treating oncologist determines which investigations are appropriate.

Immunotherapy vs Chemotherapy: What Is the Difference?

Immunotherapy and chemotherapy work differently, although both can be used in cancer treatment.

Chemotherapy uses medicines that damage or kill rapidly dividing cells. Immunotherapy works by helping the immune system recognise or attack cancer through specific biological mechanisms.

Chemotherapy may affect healthy rapidly dividing cells, while immunotherapy can cause inflammation when the immune system attacks healthy tissues. Both treatments have potential benefits and risks.

Neither is universally better than the other. The appropriate treatment depends on the cancer type, stage, tumour biology and individual patient circumstances.

Frequently Asked Questions About Cancer Immunotherapy

Is immunotherapy a cure for cancer?

Immunotherapy is not a universal cure for cancer. Some patients experience long-lasting responses, but outcomes vary depending on the cancer, treatment and individual circumstances.

Does immunotherapy work for every cancer patient?

No. Some cancers respond better than others, and even patients with the same cancer type may have different outcomes. Biomarker testing and clinical assessment can help determine whether a treatment may be appropriate.

Is immunotherapy safer than chemotherapy?

Neither treatment is universally safer. Their side effects differ, and both can cause serious complications. The treating oncologist evaluates the potential benefits and risks for each patient.

How long does immunotherapy treatment last?

Treatment duration depends on the medicine, cancer type, response to treatment and side effects. Some regimens are given over a defined period, while others may continue until a planned endpoint or a reason to stop treatment arises.

Can immunotherapy be combined with other cancer treatments?

Yes. In selected cases, immunotherapy may be combined or sequenced with chemotherapy, radiation therapy, surgery or targeted therapy. The treatment plan depends on the diagnosis and evidence supporting that approach.

Conclusion

Cancer immunotherapy has expanded treatment possibilities by helping the body’s immune system recognise and fight certain cancers. Different approaches, including immune checkpoint inhibitors, monoclonal antibodies and CAR T-cell therapy, are used in specific clinical situations.

However, immunotherapy is not appropriate for everyone, and its effectiveness and side effects vary. Understanding the available options and discussing them with a qualified oncologist can help patients make informed decisions about their care.

At Galaxy Super Speciality, we encourage patients and families to seek reliable medical information and consult qualified healthcare professionals when exploring cancer treatment options.

Medical disclaimer: This article is intended for general educational purposes only. It does not replace medical advice, diagnosis or treatment from a qualified healthcare professional.