Immunotherapy and chemotherapy are common cancer treatments. Both use drugs to stop the cancer from growing, but they achieve this in different ways. Immunotherapy enhances the immune system so it can target cancer cells. Chemotherapy directly acts on cancer cells, preventing them from replicating.
This article will look at the definitions of both immunotherapy and chemotherapy. It will also discuss each course of action, administration, side effects, cost, and more.
Chemotherapy is a treatment that uses drugs to target cancer cells. These drugs kill the dividing cancer cells and stop them from growing and replicating.
How does it work?
When new cells form, they go through a series of phases to become fully functioning, or mature, cells. Medical professionals refer to this process as the cell cycle.
Different chemotherapy drugs target cells that are at different phases of this cycle.
Some chemotherapy drugs damage the cells at the point of splitting. Others damage the cells as they make copies of their genes before splitting.
Chemotherapy tends to damage rapidly growing and dividing cells. Some chemotherapy drugs
Chemotherapy drugs do not differentiate between cancer cells and healthy cells. This means that they can cause damage to healthy cells, which can lead to a number of side effects.
Types of drugs
There are a variety of chemotherapy drugs, and they all work in different ways.
Below are some of the most common chemotherapy medications:
- Alkylating agents: These drugs damage the DNA of cancer cells, which stops the cells from reproducing.
- Nitrosoureas: This group of drugs can cross the blood-brain barrier, which keeps most drugs out of the brain.
- Antimetabolites: These drugs act as a substitute for the building blocks of cancer cells. As a result, the cells cannot make copies of themselves.
- Anti-tumor antibiotics: Anti-tumor antibiotics change the DNA inside cancer cells to prevent them from growing and replicating.
- Topoisomerase inhibitors: Topoisomerases are enzymes that help separate the strands of DNA so the enzymes can replicate. Topoisomerase inhibitors interfere with these enzymes, preventing them from replicating.
- Mitotic inhibitors: These drugs use compounds that come from natural products, such as plants. They stop cells from dividing and can also damage cells in all phases of the cell cycle.
The treatment can boost the immune system or change how it functions, enabling it to find and attack cancer cells in the body.
How does it work?
A person’s immune system detects and destroys abnormal cells. It also prevents or curbs the growth of many cancers.
The immune system can prevent and slow cancer growth. However, cancer cells can have genetic changes that make them less visible to the immune system.
Cancer cells may also have proteins on their surface that can turn off immune cells. Others can change the normal cells around the tumor, causing them to interfere with how the immune system works.
Immunotherapy helps the immune system to be more effective when responding to cancer cells.
Some immunotherapy drugs block the immune checkpoints, which usually prevent a person’s immune system from responding too strongly.
Blocking these checkpoints allows the immune cells to respond more strongly than normal to cancer cells.
Other immunotherapy drugs boost the immune cells’ natural ability to deal with cancer cells.
Types of drugs
There are a number of immunotherapy drugs that work in different ways.
- Checkpoint inhibitors: These block the immune checkpoints that typically prevent the immune system from responding too strongly.
- Chimeric antigen receptor T cell therapy: A medical professional removes some T cells, which are a type of immune cells, from the person’s blood and mixes them with a virus. The virus helps the T cells better attack cancer cells.
- Cytokines: This treatment uses cytokines — small proteins that carry messages between cells — to stimulate the immune cells to attack cancer.
- Immunomodulators: These drugs boost the immune system’s response to cancer.
- Cancer vaccines: These drugs help the immune system begin its response against certain conditions.
- Monoclonal antibodies: This treatment uses artificially made proteins that bind to specific parts of cancer cells. This marks the cells so the immune system can detect them more easily.
Healthcare professionals administer chemotherapy and immunotherapy in the following ways:
A person receives their chemotherapy drugs intravenously (IV) as an infusion or injection.
During an infusion, a healthcare professional inserts the drugs into a person’s body through a thin tube called a catheter. The catheter enters the body through an artery, vein, body cavity, or other body part.
Administration of the chemotherapy drugs can take place in the following ways:
- IV push: A healthcare professional will administer the drugs using a syringe. This method may take just a few minutes.
- IV infusion: A device called an IV pump controls the rate at which the drugs flow into the body. This can take a few minutes to a few hours.
- Continuous infusion: Electric IV pumps administer the drugs slowly. This can take 1 or several days.
Other methods of chemotherapy administration include:
- Intrathecal: The drugs enter the spinal canal via a catheter.
- Intra-arterial: The drugs enter the main artery that supplies blood to the tumor.
- Intracavitary: A healthcare professional administers the drugs into an enclosed area of the body, such as the bladder or chest.
- Intramuscular: A healthcare professional injects the drugs into a muscle.
- Intralesional: A healthcare professional injects the drugs directly into the tumor.
- Intravesical: A person receives the drugs into the bladder through a soft catheter.
- Oral: A person takes their chemotherapy drugs in the form of a pill.
- Topical: A person applies to their skin a topical cream containing chemotherapy drugs.
A healthcare professional will administer immunotherapy in the following ways:
- through an IV
- as a tablet
- as a topical cream
- through a catheter into the bladder
Both treatments cause side effects.
Chemotherapy can damage healthy cells as well as cancer cells. This can lead to a number of side effects.
Common side effects of chemotherapy include:
- hair loss
- bruising and bleeding
- nausea and vomiting
- changes in appetite
- constipation and diarrhea
- mouth, tongue, and throat sores
- difficulty swallowing
- nerve issues, such as numbness, tingling, and pain
- dry skin and skin color changes
- urine and bladder changes
- fluctuation in weight
- difficulty focusing
- mood changes
- changes in libido
- fertility issues
Immunotherapy can also cause a variety of side effects. These often occur when the body’s immune response is dramatically increased in order to deal with the cancer.
Common side effects of immunotherapy include:
- fever and chills
- nausea and vomiting
- muscle aches
- joint pain
- breathing issues
- high or low blood pressure
Other slightly less common side effects include:
Chemotherapy and immunotherapy can both treat many types of cancer.
Doctors can use chemotherapy:
- to shrink a tumor before surgery
- after surgery takes place, to remove remaining cancer cells and delay or prevent a recurrence
- during remission to remove remaining cancer cells and delay or prevent a recurrence
- in the later stages of cancer to slow its progression and reduce symptoms
While doctors do not use immunotherapy as widely as they do chemotherapy, it is also a common treatment for almost all cancer types.
Both immunotherapy and chemotherapy can be effective cancer treatments. One is not better than the other.
The effectiveness of each treatment depends on the type and stage of cancer a person has.
When deciding on a treatment, a person should speak with a doctor about possible treatment options and how these will affect their personal situation.
A doctor will be able to explain the advantages and disadvantages of each treatment and determine which option is most suitable for a person’s specific needs.
The cost of chemotherapy and immunotherapy may vary and will depend on a number of factors, such as the:
- type and stage of cancer a person has
- number of treatments they require
- duration of each treatment
- specific type of chemotherapy or immunotherapy they need
- place where they will undergo their treatment
- area in which they live
Most healthcare plans cover some of the cost of both chemotherapy and immunotherapy. However, depending on the insurance plan a person has, they may have to pay some of the cost themselves.
It is important that a person knows the following information about their healthcare policy:
- the terms of their insurance policy
- the preferred or network doctors, hospitals, or clinics, according to the policy
- detailed records of their healthcare costs
Medicare Part A covers the cost for hospital inpatients. Medicare Part B, on the other hand, covers the cost if a person is an outpatient or receives their treatment in a doctor’s office or free-standing clinic.
For those without insurance
A person can try the following to get financial help to cover the cost of cancer treatments:
- Healthcare.gov, which provides information about health insurance options that may be available under the Affordable Care Act
- the Department of Veterans Affairs, which provides benefits to those in the United States military, veterans, and family members
- Medicaid, which can help provide benefits for those with a limited income
A person can also use the following directories and resources to find programs depending on their location and the cancer type:
- American Cancer Society
- National Cancer Institute
- Cancer Financial Assistance Coalition
- HealthWell Foundation
- Leukemia & Lymphoma Society
- Triage Cancer
Immunotherapy and chemotherapy are two common cancer treatments.
Chemotherapy uses drugs to locate and destroy cancer cells. Immunotherapy helps a person’s immune system better fight their cancer.
Healthcare professionals often use chemotherapy and immunotherapy together in the same treatment plan.
A person should speak with a doctor when deciding which treatments to choose for their condition.