All You Need to Know about Cancer Immunotherapy | Dr. Smit Sheth,  Consultant Cancer Specialist | MOC, Thane

All You Need to Know about Cancer Immunotherapy | Dr. Smit Sheth, Consultant Cancer Specialist | MOC, Thane

Q1. Immunotherapy for cancer treatment is becoming very popular these days? What is it? 
Answer: In traditional treatments, the doctor tries to “beat the cancer” with chemotherapy, surgery, or radiation therapy. Immunotherapies, on the other hand, aims to put patients in the position to fight the cancer themselves by activating their own immune system.


Q2. How does the immune system work?
Answer:
Immune system is body's defense against foreign invaders. Infectious organisms such as bacteria, fungi, parasites, and viruses. All of them have specific molecular targets called “antigens”, which are recognized by the body’s immune system. When our body comes in contact with these antigens, the antigens trigger an immune response which helps containing the infection. 

Q3. How does cancer escape / fool the immune system?
Answer:
Cancer cells have antigens present on their surface but they evade patient's immune system. In some cases, the immune response is not strong enough to destroy the cancer. Some cancers can secrete the precise chemicals that signals our bodies to shut down the immune response.


Q4. How does immunotherapy work?
Answer:
The goal of immunotherapy is to wake up the immune system so that it recognizes cancer and attacks the disease; just as it does with most of the bacteria or viruses. 

Immunotherapy boosts your immune system by inhibiting or stopping immune checkpoints. An immune checkpoint is normally used by the body to naturally stop the immune system’s response and prevent it from attacking healthy cells. Cancer cells can find ways to hide from the immune system by activating these checkpoints. Checkpoint inhibitors {Immunotherapy} stop the ability of cancer cells to restrict the immune system from activating, and in turn, amplify your body’s immune system to help destroy cancer cells.

 Immunotherapy can “train” or “condition” the immune system to remember cancer cells. This “immune-memory” may result in longer-lasting and potentially permanent protection against cancer recurrence. 

Clinical studies on long-term overall survival have shown that the beneficial responses to cancer immunotherapy treatment can be durable; that is, they continue even after treatment is completed.


Q5. What are the advantages of Immunotherapy over Chemotherapy? 
Answer: Radiation and chemotherapy damage cells that divide quickly, however, they are not effective against “dormant” tumor stem cells. Thus, it can be presumed that the therapy is only effective during the course of treatment. For example, the hair starts growing again after the end of chemotherapy, so too can tumor cells start growing again.

Immunotherapy is a smart way to fight cancer. 

  • The immune system is precise; hence it is possible to target cancer cells exclusively while sparing healthy cells.
  • The immune system can adapt continuously and dynamically, just like cancer does, therefore if a tumor manages to escape detection, the immune system can re-evaluate and launch a fresh attack.
  • The immune system’s “memory” allows it to remember how cancer cells look like so that it can target and eliminate the cancer if it returns.

Q6 What are the types of Immunotherapy?
Answer:
There are many types of immunotherapy. They include:

  • Monoclonal antibodies eg. Nivolumab, Ipilimumab, Pembrolizumab, Atezolizumab and Durvalumab to name a few (These are commonly available at present).
  • Oncolytic virus therapy
  • T-cell therapy (CAR-T Cell Therapy)
  • Cancer vaccines

Q7. What are the potential side effects of Immunotherapy?
Answer:
Immunotherapy can cause side effects, many of which happen when the immune system that has been triggered to act against the cancer also acts against healthy cells and tissues in the body. Side effects can affect almost any organ of the body 

Potential side effects can range from mild to moderate and can become life-threatening only under certain circumstances. 

Fortunately, in most cases side effects can be safely managed as long as they are recognized and addressed early. Therefore, it’s extremely important that patients notify their doctor as soon as they experience any unusual developments of symptoms during or after treatment with immunotherapy. 

The timing of immunotherapy-related side effects is less predictable than with other types of cancer treatments. Patients receiving immunotherapy may develop side effects soon after receiving the first dose of a drug or long after a course of treatment has ended. 

Overall patients treated with Immunotherapy have better Quality of Life than those receiving chemotherapy.

Some common side effects are; fatigue, skin reactions, flu like symptoms, diarrhea, lung-liver injury, endocrine and autoimmune disorders.


Q8. How will immunotherapy-related side effects be managed?
Answer:
Grade 1 (mild severity) or Grade 2 (moderate severity) events generally are managed symptomatically, without interrupting or permanently discontinuing the treatment. Patients with persistent Grade 2 symptoms may need to skip one or more treatment doses until their symptoms have improved.

For patients with Grade 3 (severe) or Grade 4 (very severe) symptoms, treatment should typically be discontinued and patient should be referred to a specialist. Steroids, or other immunosuppressive drugs, are used for severe or persistent side effects; their use does not appear to compromise the efficacy of treatment with checkpoint inhibitors.

If you have to permanently stop treatment with an immune checkpoint inhibitor, this should not negatively affect how your cancer responds.


Q9. How does it feel while the immunotherapy infusion is ongoing?
Answer:
Unlike regular chemotherapy, patients does not experience nausea and vomiting. There is a small risk of infusion reaction, more common during initial infusions. Apart from that it feels like a regular “saline” infusion.  


Q10. Can people with autoimmune diseases and cancer be treated with immunotherapy?
Answer:
People with mild & controlled autoimmune diseases are able to receive most immunotherapies.  However, each patient should speak with his or her doctor regarding the options that are most appropriate.


Q11. How can I tell whether the immunotherapy is working?
Answer:
Immunotherapy treatments may take longer to produce detectable signs of tumor shrinkage compared to traditional treatments. Sometimes tumors may appear to grow on scans before getting smaller. Many patients who experience this phenomenon, known as pseudoprogression, often report feeling better overall. Patients are advised to undergo regular scans to monitor the response.

To summarize Immunotherapy for cancer treatment, it magnifies the body’s natural immune response to cancer, with a side effect profile different from regular chemotherapy. The science is evolving in terms of helping us identify which patients will benefit from immunotherapy with the advantage that those who respond to immunotherapy are likely to have sustained and durable response.  


Dr. Smit Sheth
Consultant Medical Oncologist

Mumbai Oncocare Centre
drsmitsheth@mocindia.co.in
7400424333 / 022-25301090
www.mocindia.co.in

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