Difference Between Chemotherapy and Immunotherapy
Chemotherapy and immunotherapy are two common treatments for cancer, but they work in very different ways. Chemotherapy uses potent drugs to kill cancer cells directly, while immunotherapy helps the body’s immune system fight cancer independently.
Both treatments have their benefits and side effects, and the choice between them depends on the type of cancer, how advanced it is, and how the patient’s body responds to treatment.
Some cancers respond better to chemotherapy, while others may be more suited for immunotherapy. In some cases, both treatments are combined for better results. Understanding how each therapy works can help you make an informed decision.
How Chemotherapy Works?
Chemotherapy is a drug-based treatment that targets and destroys cancer cells. It is designed to stop cancer cells from growing, dividing, and spreading to other body parts.
- Kills Cancer Cells Directly: Chemotherapy works by attacking rapidly dividing cells. Since cancer cells grow and divide faster than normal cells, chemotherapy drugs effectively stop their growth.
- Given in Cycles: Patients receive chemotherapy in cycles, with breaks in between to allow the body to recover. This helps reduce the impact on healthy cells while fighting cancer.
- Affects the Whole Body: Chemotherapy is given chiefly via an IV. Thus, the drug travels through the bloodstream. This means that the drugs can reach cancer cells anywhere in the body. This makes it useful for cancers that have spread beyond the original tumour.
- Different Ways of Administration: Chemotherapy can be given through an IV, pill, or injection. The method depends on the type of cancer and the specific drug being used.
Chemotherapy is often recommended for cancers that are aggressive or have spread to different parts of the body.
How Immunotherapy Works?
Immunotherapy helps the body’s immune system recognise and attack cancer cells. Instead of directly killing cancer cells like chemotherapy, it boosts the immune system’s ability to fight cancer on its own.
- Uses the Body’s Defense System: The immune system naturally fights infections and abnormal cells. Immunotherapy strengthens this process, making detecting and destroying cancer cells easier for the body.
- Different Types of Immunotherapy: There are several forms of immunotherapy, including checkpoint inhibitors, cancer vaccines, monoclonal antibodies, and T-cell therapy. Each type works in a unique way to boost the immune response.
- Targets Specific Cancer Cells: Some immunotherapy treatments mark the tumour cells, which can help the body’s immune system recognise and fight them better. Others remove barriers that prevent the immune system from acting against cancer.
- Long-Term Effects: Immunotherapy can continue working even after treatment has stopped. The immune system “remembers” how to fight the cancer, reducing the chances of the cancer coming back.
Immunotherapy is mainly used for cancers that do not respond well to chemotherapy, such as melanoma, lung cancer, and some blood cancers.
Key Differences Between Chemotherapy and Immunotherapy
Although both treatments fight cancer, chemotherapy and immunotherapy have several significant differences.
- Method of Action: Chemotherapy attacks and destroys cancer cells directly, while immunotherapy helps the immune system recognise and fight cancer cells.
- Treatment Area: Chemotherapy works throughout the body, affecting cancerous and healthy cells. Immunotherapy is more targeted, boosting the body’s natural defences to fight cancer cells.
- Side Effects: Both treatment options can cause similar symptoms. Chemotherapy causes nausea, hair loss, and fatigue because it affects healthy cells as well. Immunotherapy side effects are usually related to immune system activity, including inflammation, skin rashes, or flu-like symptoms.
- Effectiveness: Some cancers respond better to chemotherapy, while others respond better to immunotherapy. The effectiveness of each treatment depends on the type of cancer and the individual patient.
Side Effects of Chemotherapy and Immunotherapy
Both chemotherapy and immunotherapy have side effects, though they affect the body differently.
- Chemotherapy Side Effects:
- Nausea and vomiting are common and may require medication to control.
- Hair loss can occur because chemotherapy affects fast-growing cells, including hair follicles.
- One of the long-known side effects of chemotherapy is a weakened immune system. This can sometimes increase the risk of catching other infections.
- Fatigue is common and may last throughout treatment and recovery.
- Immunotherapy Side Effects:
- Skin rash and irritation may occur as the immune system becomes more active.
- Some patients also report having flu-like symptoms. This can include fevers and body aches.
- Inflammation in organs like the lungs or liver can happen in rare cases.
- Fatigue may occur but is usually less severe than with chemotherapy.
Doctors monitor patients closely and adjust treatments if side effects become too difficult to manage.
When is Chemotherapy Recommended?
Chemotherapy is commonly used for cancers that grow and spread quickly. It is often recommended in the following situations:
- For Advanced or Widespread Cancer: If cancer has spread beyond the original site, chemotherapy is helpful because it treats the whole body.
- Before or After Surgery: Chemotherapy can help shrink tumours before surgery or destroy remaining cancer cells after surgery.
- As a Main Treatment: Some cancers, such as leukaemia and lymphoma, require chemotherapy as the primary treatment.
- In Combination with Other Treatments: It is sometimes combined with immunotherapy, radiation therapy, or surgery for better results.
When is Immunotherapy Recommended?
Immunotherapy is not used for all cancers but can be very effective for certain types. It is recommended in the following situations:
- For Certain Cancer Types: Immunotherapy is commonly used for melanoma, lung cancer, bladder cancer, and some blood cancers.
- When Other Treatments Are Not Effective: Immunotherapy may be considered an alternative if chemotherapy or radiation does not work.
- For Long-Term Cancer Control: In some cases, immunotherapy helps train the immune system to fight cancer even after treatment ends.
- As a Targeted Approach: Since immunotherapy is designed to work with the immune system, it is more focused and practical for cancers that do not respond well to chemotherapy.
Frequently Asked Questions
Amerix Cancer Hospital is one of the best hospitals for complete cancer care in Delhi. Its specialised medical team with advanced treatment options and world-class facilities makes it the best choice for cancer treatment. The hospital hosts a team of medical experts experienced in cancer treatments like chemotherapy and immunotherapy. Amerix focuses on making treatment as practical and comfortable as possible for each individual.
Yes, in some cases, chemotherapy and immunotherapy are used together. Chemotherapy weakens cancer cells, making them easier for the immune system to attack. Combining both treatments can improve the effectiveness of certain cancers. The decision depends on the type of cancer and how the patient’s body responds.
Immunotherapy generally has fewer side effects than chemotherapy because it mainly targets cancer cells. However, it can still cause immune reactions like inflammation and fatigue. Chemotherapy has more widespread effects because it impacts healthy cells as well, leading to nausea, hair loss, and a weakened immune system.
The choice between chemotherapy and immunotherapy depends on the type of cancer, its stage, and how the body responds to treatment. The best treatment options should be made only after consulting doctors. Only an experienced doctor can assess the patient’s condition and recommend treatment. Some cancers respond better to one treatment, while others may require a combination of both.
References
https://www.cancer.gov/about-cancer/treatment/types/immunotherapy
https://www.webmd.com/cancer/immunotherapy-risks-benefits
https://www.cancer.gov/about-cancer/treatment/types/immunotherapy/side-effects
https://my.clevelandclinic.org/health/treatments/11582-immunotherapy
https://my.clevelandclinic.org/health/treatments/16859-chemotherapy
https://www.nhs.uk/conditions/chemotherapy
https://www.mayoclinic.org/tests-procedures/chemotherapy/about/pac-20385033
