An Overview of the Types of Chemotherapy Used to Treat Cancer

There are many different types of chemotherapy drugs that are used to treat cancer. Often, patients receive more than one type of chemotherapy drug. These drugs are very different in their chemical composition, how they are prescribed and given, how useful they are in treating certain types of cancer, and the side effects they might have.

In this article, we'll discuss the different types of chemotherapy drugs, their side effects, and the types of cancer they treat.

How Many Types of Chemotherapy Drugs Are There?

There are more than 100 types of chemotherapy drugs. The main types are:

• Alkylating agents: These drugs keep cells from making copies of themselves by damaging their DNA. These drugs work in all phases of the cell cycle.
• Antimetabolites: Antimetabolites also stop cancer cells from replicating. They do this by acting as a substitute for the normal building blocks of RNA and DNA. 
• Anti-tumor antibiotics: This type of drug changes the DNA inside cancer cells to keep them from growing and multiplying.
• Topoisomerase inhibitors: DNA within the body need the enzyme topoisomerase to replicate. Topoisomerase inhibitors stop that process, leading to the death of cancer cells. 
• Mitotic inhibitors: Cell division, also known as mitosis, is a crucial part of cancer growth in the body. Mitotic inhibitors stop this process.
• DNA repair enzyme inhibitors: In the event that a cancer cell becomes physically damaged, a DNA repair enzyme, a type of protein, will recognize the damage and attempt to fix it. DNA repair enzyme inhibitors stop this from occurring, which results in the death of cancer cells.
• Plant alkaloids: Plant alkaloids are agents derived from plants that stop cancer cells from dividing in the body, thus stopping cancer spread and growth.
• Antineoplastics: This type of chemotherapy medication is designed to target and kill cancer cells.

How Chemotherapy Treats Cancer

Every time any new cell is formed, it goes through a usual process to become a fully functioning cell. The process involves a series of phases and is called the cell cycle. Cancer cells go through the same process. Chemotherapy drugs work by targeting cells at different phases of the cell cycle. 

When chemotherapy kills cancer cells, it is known as cytotoxic. The drugs used in chemotherapy can travel throughout the body, finding cancer cells that have spread away from where the tumor originally formed.

Different chemotherapy drugs work on cancer cells in different ways. Because cancer cells grow faster than normal, healthy cells, chemotherapy drugs target them better than healthy cells. However, chemotherapy drugs can damage healthy cells as well, which can lead to severe side effects.  

The Cancers That Chemotherapy Treats

Chemotherapy can treat a wide variety of cancers. Typically, chemotherapy is used when surgery is not an option or it's performed after surgery. Cancers that can be treated by chemotherapy include:

• Brain cancer
• Lung cancer
• Breast cancer
• Ovarian cancer
• Gastrointestinal cancer
• Leukemia
• Lymphoma
• Hodgkin's lymphoma
• Multiple myeloma
• Sarcoma

The Ways Chemotherapy Is Given to Patients

When receiving chemotherapy, the drugs may come in the following forms:

• Oral: Some chemotherapy drugs are taken by mouth in the form of liquids, pills, or capsules.
• Intravenous (IV): Chemotherapy drugs can be administered directly into the bloodstream via a vein using an IV. Getting chemotherapy through an IV may also be done through ports, catheters, or with a pump. A catheter is a thin tube that is placed into a large vein in the chest. A port is a disc that is placed under the skin during surgery and stays in place during your chemotherapy treatment. In some cases, a pump will be attached to a port or a catheter to control how much of the medication is administered and how quickly.
• Injection: In some cases, chemotherapy drugs are injected with a needle into a muscle in the arm, thigh, hip, or under the skin in fattier areas such as the arm, leg, or stomach.
• Intraperitoneal: Chemotherapy can also be administered directly into the peritoneal cavity, which is the space within the abdomen that houses the stomach, liver, and intestines.
• Intra-arterial: Some types of chemotherapy drugs will be put directly into an artery that has a direct blood flow to the area where the cancer is found.
• Topical: Applying chemotherapy drugs topically, in cream on the skin, is also possible.

Side Effects of the Types of Chemotherapy

The most common side effects of chemotherapy include:

• Nausea and vomiting
• Fatigue
• Decrease in appetite
• Changes to how things taste
• Hair loss
• Constipation
• Dry mouth

Nausea and vomiting are often the most common side effects. In some cases, they can be so severe that they lead to an inability to absorb nutrients, weight loss, low red blood cell count (anemia), fatigue, and an increased risk of sepsis, where the body's response to an infection damages its own tissues.

Other chemotherapy side effects can include:

• Infection
• Easy bruising or bleeding
• Diarrhea
• Mouth sores
• Pain while swallowing
• Nerve issues, such as numbness, tingling, and pain
• Dry skin and nails
• Changes in the color of the skin and nails
• Mental fog, also known as chemo brain, which affects cognitive functions such as concentration and memory 
• Mood changes
• Changes in libido
• Fertility issues

What to Expect From Treatment

If you are receiving chemotherapy in the hospital, you may want to bring some personal items with you, such as a book to read or a blanket to keep you warm. Having a friend or family member with you during your first treatment session will also be helpful for remembering important information and getting moral support. In some cases, medication will be provided that will cause you to become drowsy, so arranging for a ride home beforehand may be necessary.

You may also be given infusion chemotherapy treatment through a small pump that you have to carry with you. You should prepare yourself for potential side effects, but try to remain as calm as possible.

Summary

Chemotherapy helps disrupt the process through which cancer cells make copies of themselves. There are more than 100 types of chemotherapy drugs, with the main types being alkylating agents, antimetabolites, anti-tumor antibiotics, topoisomerase inhibitors, and more. They target different parts of the cell replicating process. Different types are used to treat different cancers. For example, alkylating agents are commonly used to treat leukemia and lymphoma.

A Word From Verywell

Getting diagnosed with cancer can be devastating. However, with advances in medical science and a wide array of options for treatment available, many forms of cancer can be treated. Chemotherapy, especially, has been shown to be an effective treatment option.

It is important to remember that not all people will have the same side effects, and some people will experience no side effects at all. Keep in mind that chemotherapy is meant to restore you to good health. While you’re going through your treatment, be prepared for side effects and eat as well as you can. That will allow you to cope with your diagnosis and your treatment effectively.

Frequently Asked Questions

Will certain types of chemotherapy impact your nails and skin?

Chemotherapy drugs aim to target cancer cells, but they can also have a negative effect on the rest of your body, including your nails and skin. In most cases, the skin and nails will return to normal after treatment.

Will chemotherapy affect your nutrition?

Because chemotherapy can lead to malabsorption of nutrients as well as nausea, vomiting, and diarrhea, it can affect the level of nutrients in your body. Roughly 83% of older adults who undergo chemotherapy will also experience malnutrition.

Which types of chemotherapy are given orally?

Not all types of chemotherapy drugs are given orally, but there are quite a few that can be taken that way. For example, alkylating agents and antineoplastics can be given orally. Although oral chemotherapy is more convenient, research has shown that people given their chemotherapy orally struggle to adhere to their medication schedule.