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Cancer is a large group of conditions caused by the rapid division of abnormal cells. Chemotherapy is one treatment option that involves receiving medication that keeps cancer cells from spreading.

Chemotherapy can be effective either on its own or with other treatments. But it also has the potential to lead to mild or serious side effects.

More than half of the people who receive chemotherapy experience at least one side effect. The most common side effects are:

  • fatigue
  • diarrhea
  • constipation

Keep reading as we break down the different types of chemotherapies used to treat cancer, and what to expect in terms of side effects.

Chemotherapy is a chemical drug therapy that’s often used to destroy cancer cells in your body.

Chemotherapy may be used as the primary treatment for your cancer, or it may be used to prepare you for other treatments such as radiation therapy or surgery.

One 2017 study showed that the FDA approved at least 150 chemotherapy drugs to treat cancer. The type of drug your healthcare professional will recommend for your chemotherapy depends on factors such as:

  • your age
  • your overall health
  • the type of cancer you have
  • how much the cancer has spread
  • your previous treatments
  • your personal preferences

Chemotherapy drugs are broadly classified based on their mode of action. The main categories include:

  • alkylating agents
  • plant alkaloids (topoisomerase inhibitors and mitotic inhibitors)
  • anti-metabolites
  • anti-tumor antibiotics
  • corticosteroids
  • miscellaneous other drugs

This table shows which cancers these types of chemotherapy are typically used for.

Type of chemotherapyCancer it may be used to treat
alkylating agents multiple myeloma sarcoma
Hodgkin’s disease
lung cancer
breast cancer
ovarian cancer
plant alkaloids:
topoisomerase inhibitors
leukemia
pancreatic cancer
ovarian cancer
gastrointestinal cancer
lung cancer
plant alkaloids:
mitotic inhibitors
breast cancer
lung cancer
myelomas
lymphoma
leukemia
anti-metabolitebreast cancer
leukemia
ovarian cancer
gastrointestinal cancer
anti-tumor antibiotics lung cancer
colorectal cancer
ovarian cancer
prostate cancer
corticosteroidsmay be used to treat cancer or prevent gastric side effects or allergic reactions from chemotherapy

Below we look at each type of chemotherapy in more detail, along with their potential side effects.

According to the National Cancer Institute, alkylating agents are the most common category of drugs used in chemotherapy today.

Alkylating agents damage the DNA of cancer cells and prevent them from dividing. Some of the drugs that fall into this category include:

  • chlorambucil
  • cyclophosphamide
  • thiotepa
  • busulfan

Alkylating agents can be used for most types of cancers but are generally best at treating slow-growing cancers.

Some cancers that alkylating agents may help treat include:

Potential side effects

High doses of alkylating agents can potentially damage bone marrow, which can lead to leukemia. The risk of developing leukemia becomes higher at higher dosages.

According to the American Cancer Association, the risk of developing leukemia is highest after 5 to 10 years of treatment.

Other common side effects include:

Healthline

Plant alkaloids are drugs derived from plants with anti-tumor properties. They can be divided into several subcategories.

Topoisomerase inhibitors

Topoisomerase inhibitors block cancer cells from dividing and spreading by interfering with enzymes called topoisomerases. Some commonly used plant alkaloids include:

  • irinotecan
  • topotecan
  • teniposide

These drugs treat some cancers, including:

  • leukemia
  • pancreatic cancer
  • ovarian cancer
  • gastrointestinal cancer
  • lung cancer

Topoisomerase inhibitors can be divided into topoisomerase I and topoisomerase II depending on which enzyme they affect.

Drugs that fall in the subgroup called topoisomerase II inhibitors can increase your risk of developing a second cancer.

Potential side effects

Potential side effects from topoisomerase inhibitors include:

Healthline

Mitotic inhibitors

Miotic inhibitors prevent cancer cells from replicating by inhibiting enzymes the cells needs to make certain proteins. Some examples include:

  • cabazitaxel
  • docetaxel
  • vinorelbine

Miotic inhibitors may help treat:

  • breast cancer
  • lung cancer
  • myeloma
  • lymphoma
  • leukemia

Potential side effects

High doses of mitotic inhibitors can cause nerve damage. A few of the other potential side effects from mitotic inhibitors include:

Healthline

Anti-metabolite drugs replace structures in the DNA of cancer cells and alter the function of enzymes within the cell. Some drugs that fall in this category include:

  • azacitidine
  • clofarabine
  • floxuridine

Anti-metabolites are often used to treat these cancers among others:

Potential side effects

Some potential side effects from anti-metabolites include:

Healthline

Anti-tumor antibiotics are different from antibiotics used to treat infections. A 2020 research review showed that anti-tumor antibiotics are chemicals produced by microorganisms that help destroy cancer cells.

Anti-tumor antibiotics work by uncoiling strands of DNA inside cancer cells and preventing them from replicating. The following medications fall into this category:

  • doxorubicin
  • bleomycin
  • mitoxantrone

They’re widely used to treat the following cancers among others:

  • lung cancer
  • colorectal cancer
  • ovarian cancer
  • prostate cancer

Potential side effects

High doses of anti-tumor antibiotics can cause heart damage. Healthcare professionals often put lifetime limits on how much can be given. Other common side effects include:

Healthline

Corticosteroids, or just steroids, are hormone-like drugs used in the treatment of many illnesses. They may be used during chemotherapy to directly treat cancer or help prevent gastric side effects and allergic reactions caused by other drugs.

Corticosteroids come with their own risks of side effects such as:

Many other drugs can be used in chemotherapy that don’t fall into one of the previous categories. A few of these include:

  • hydroxyurea
  • mitotane
  • pegaspargase
  • estramustine
  • bexarotene

Chemotherapy can be used by itself or along with other treatment options to target cancer. Here are some of the other treatments your healthcare professional may recommend.

Targeted therapies

Targeted therapies are drug therapies that aim to kill cancer cells by targeting the following that are unique to cancer:

  • genes
  • proteins
  • receptors

Unlike chemotherapy, targeted therapies specifically target cancer cells and mostly avoid damaging healthy cells.

Immunotherapy

Immunotherapy is a drug therapy that boosts your immune system to help your body recognize and kill cancer cells.

Unlike with chemotherapy, chemicals in immunotherapy drugs don’t directly kill cancer cells but enhance your body’s ability to fight them.

Hormone therapy

Some types of cancers need certain hormone levels to grow. Hormone therapies help inhibit the growth of cancer cells by changing hormone levels in your body.

Some types of cancer sensitive to hormone levels include:

Surgery

In some cases, the best option may be to remove the cancer from your body surgically. Surgery works best for cancers that are localized in one area.

Radiation therapy

Radiation therapy uses low doses of radiation to kill cancer cells by damaging their DNA. It not only affects cancer cells but also healthy cells as well. It commonly leads to side effects such as:

  • loss of appetite
  • nausea
  • fatigue

Chemotherapy is a chemical drug therapy that helps destroy cancer cells.

There are many drugs that can be used during chemotherapy. Your healthcare professional can help you find which drug is best for your particular situation.

Chemotherapy can be used as the primary treatment for your cancer, or it may be combined with other treatments like:

  • surgery
  • immunotherapy
  • hormone therapy