What Is Chemotherapy Treatment?

There are many types of chemotherapy to treat cancer and other conditions. When starting therapy, many people worry about the process, how treatment works, how it will make them feel, and what side effects to expect.

In this article, we'll discuss what to expect from chemotherapy, how well it works, and the process you will go through during treatment.


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Chemotherapy is a group of medications used to treat cancer and sometimes other conditions. In cancer, chemotherapy—oftentimes simply called "chemo"—works by killing cancer cells.

Each type of chemotherapy drug does this a little bit differently, at a different time in the cell's reproductive cycle. Some drugs may affect the genes as the cell is about to split, and others, as copies of genes are being made before the split occurs.

Despite their individual differences, most chemotherapy drugs follow the same pattern in terms of how they work in the body: The medication enters the nucleus and damages the genes of the cells.

Conditions Treated

Chemotherapy is most often used to treat cancer, but chemo drugs may also be used to treat autoimmune diseases, in which the immune system is overactive and attacks healthy cells by mistake, including:

Who Administers Chemo

If your chemo is used to treat cancer, your oncologist, a doctor specializing in the diagnosis and treatment of cancer, will oversee your treatment. If chemo is used to treat other conditions, it will be administered by doctors who specialize in treating those conditions. For example, for lupus, it will be a rheumatologist.


There are hundreds of types of chemotherapy, and your doctor will choose one or more based on the type, location, and stage of your cancer or other disease. Chemotherapy comes in a variety of forms that can be given:

  • Orally
  • Intravenously (IV, through a vein)
  • Topically (on the skin)
  • Injected as a single shot

Most chemotherapies are given systemically—meaning they impact the entire body—but some may also be given as targeted therapies. This means that the medication is directed toward a specific area of the body to focus the treatment there and possibly reduce the impact on other parts of the body. Some examples of direct or targeted chemotherapies include:

  • Intra-arterial chemotherapy: This is given through a specific artery that is supplying blood to a tumor.
  • Intracavitary chemotherapy: This is given directly in a cavity (opening) or organ, like the bladder.
  • Intrathecal chemotherapy: This is given in the open space between the brain and spinal cord.

Chemo medications are generally split into several classes or categories.

Alkylating Agents

These are used to treat cancers such as:

  • Leukemia
  • Lymphoma
  • Hodgkin's lymphoma (or Hodgkin's disease)
  • Multiple myeloma
  • Sarcoma
  • Brain cancers
  • Lung cancers
  • Breast cancers
  • Ovarian cancers

Examples of specific medications include:

  • Myleran (busulfan)
  • Cytoxan (cyclophosphamide)
  • Temodar (temozolomide)


These are used to treat cancers like:

  • Leukemia
  • Breast cancers
  • Ovarian cancers
  • Intestinal cancers

Examples of specific medications include:

  • 5-FU (5-fluorouracil)
  • 6-MP (6-mercaptopurine)
  • Xeloda (capecitabine)
  • Gemzar (gemcitabine)

Antitumor Antibiotics

These are used to treat a wide variety of cancers.

Examples of specific medications include:

  • Cosmegen (dactinomycin)
  • Blenoxane (bleomycin)
  • Cerubidine, Rubidomycin (daunorubicin)
  • Adriamycin PFS, Adriamycin RDF (doxorubicin)

Topoisomerase Inhibitors

These are used to treat cancers like:

  • Leukemia
  • Lung cancers
  • Ovarian cancers
  • Gastrointestinal cancers

Examples of specific medications include:

  • VP-16 (etoposide)
  • Camptosar (irinotecan)
  • Hycamtin (topotecan)

Mitotic Inhibitors

These are used to treat cancers like:

  • Myeloma
  • Lymphomas
  • Leukemias
  • Breast cancers
  • Lung cancers

Examples of specific medications include:

  • Taxotere (docetaxel)
  • Halaven (eribulin)
  • Ixempra (ixabepilone)
  • Taxol (paclitaxel)
  • Alkaban (vinblastine)

How Chemotherapy Is Used to Treat Cancer

Chemo can be used in different ways to treat cancer, including:

  • Adjuvant therapy: This is when chemotherapy is used to kill cancer cells after a surgical or radiation treatment, or along with other treatments.
  • Curative therapy: Refers to when chemotherapy is used as the only treatment for your cancer.
  • Neoadjuvant therapy: This is used to shrink tumors before surgical or radiation treatment.
  • Palliative therapy: This is when chemotherapy is used to control—but not cure—your cancer in an effort to reduce symptoms and improve quality of life.


For chemotherapy given intravenously, the type and duration of your therapy and how you will receive your medication will be set when you are ready to start treatment. In the past, chemotherapy was administered in an inpatient setting, but now most therapies take place as outpatient treatments in special offices or facilities.

In most cases, a nurse or infusion specialist will administer the medication over several hours, which includes time for observation after your treatment session is complete.

The typical process at an infusion appointment may follow these steps:

  • You will register at the chemotherapy infusion center, just as you would check in for a doctor's appointment.
  • A nurse or infusion specialist will go over your medical history and what chemotherapy medication you will receive.
  • Your vital signs, including your blood pressure, temperature, height, and weight will be recorded.
  • If you don't already have intravenous access, like a port, a small device inserted under the skin for drawing blood and administering treatment, or a catheter, a thin, flexible tube, this will be placed for you.
  • Blood will be drawn from your vein so that your blood cell count can be recorded.
  • A medical oncologist will review your vitals and recent test results, and use this information to calculate the exact amount of medication you need.
  • You may receive "pre-chemotherapy" medications like fluids or drugs to help prevent side effects like nausea.
  • During your infusion, you may want to nap, try to relax, or engage in a leisure activity like reading to pass the time.
  • Your infusion nurse or specialist will monitor your health and vital signs for allergic reactions or other side effects during your treatment.
  • Once the infusion is complete, your IV will be removed or you will be disconnected from your infusion and your port or catheter will be flushed and capped for later use.
  • Your vital signs will be taken again, and your nurse will perform an assessment to see if you have any major reactions or side effects.
  • You will review what to expect once you go home, how to manage side effects, and when to call the doctor. You may be given additional prescriptions to help with the side effects.
  • While you may be able to drive yourself home after your chemo appointment, it may be better to arrange for transportation. Chemotherapy can leave you feeling tired and drained.
  • Before you leave your appointment, your next infusion appointment will be scheduled.

How to Prepare

Before you start chemotherapy, one of the first things you and your medical team will discuss is how you will get your chemotherapy medication. If it's oral, topical, or by way of injections, the medications can be taken fairly simply. If your chemotherapy is intravenous, you will need to visit a facility for regular infusions.

When chemotherapy is given through a vein, it may be more convenient and safer to have a semipermanent site rather than having intravenous access placed for every infusion. Options for intravenous chemotherapy include:

  • Needles or catheters placed in your vein for each infusion
  • A catheter that is inserted under the skin and can be left for a period of time
  • A port placement, which involves a small disc implanted under the skin that connects to a catheter during treatment

Next, your doctor will determine the type of medication, frequency, and duration of your chemotherapy cycle. There are many factors to consider when determining the length and frequency of a chemotherapy cycle, and each cycle can last for several months or even as long as a year.

Why Is Chemo Effective?

The reason chemotherapy is so effective in killing cancer cells is that these types of cells divide quickly and reproduce rapidly to form a mass commonly known as a tumor. These tumors overtake normally functioning cells and tissues. As these masses of cells grow larger, they can create obstructions or interfere with the normal function of tissue.

Side Effects

Not everyone experiences side effects from chemotherapy, and how severe the side effects are can vary from one person to the next. Even if you do have side effects, your medical team will likely prescribe additional medications to help you manage them.

Since chemotherapy medications target cells in their reproductive phase, other healthy cells that undergo rapid reproduction are also vulnerable to side effects. These include:

  • Cells in the bone marrow that make blood
  • Hair follicles
  • Cells in the mouth and digestive tract
  • Cells in the reproductive system

The most common side effects of chemotherapy include:

Each class of chemotherapy can cause additional side effects:

  • Alkylating agents: Damage to the bone marrow or increased risk of leukemia
  • Antitumor antibiotics: Cardiac damage at high doses
  • Topoisomerase inhibitors: Increased chances of developing secondary cancers, even several years later
  • Mitotic inhibitors: Increased risk of painful nerve damage

Some side effects may last just a few hours, and others may be more permanent. Typically, side effects like headache and nausea will pass, while damage to the heart, kidneys, or nerves can be long-lasting.

You will also want to talk to your doctor about any other medications or vitamins you take while you receive chemotherapy since some can interact with chemo drugs.

New Strategies for Chemotherapy

Traditionally, chemotherapy dosing has been a balancing act between giving the highest possible doses of chemotherapy medication to kill high numbers of cancer cells while sparing as many healthy cells as possible.

A new type of chemo treatment called metronomic chemotherapy involves the use of continuous or regular low doses of chemotherapy over a longer period of time. The goal is to stop the growth of new blood vessels that feed cancer cells while causing less severe side effects than traditional chemotherapy regimens.

Outcomes and Recovery

There is no definitive prognosis for any type of cancer—with or without chemotherapy. Your prognosis depends on several factors:

  • Type of cancer
  • Location of the cancer
  • The stage of your cancer when it's detected
  • The grade of the cancer
  • Traits of your specific cancer cells
  • Age
  • Overall health at the time of diagnosis
  • Response to treatment

A medication or treatment that works for one person with a certain type of cancer may not work as well with someone else who has the same type of cancer. Some cancers are more responsive to chemotherapy than others, too. You and your medical team should go over this information together when developing your plan of care.


Chemotherapy is a group of medications used to treat cancer and sometimes other conditions. They kill cancer cells by disrupting their reproductive cycle and stopping them from multiplying. Chemo drugs can be administered intravenously into your bloodstream, taken orally, applied topically, or injected as a shot. They are effective at treating cancer, but can affect healthy cells in the process, leading to side effects like hair loss and fatigue.

A Word From Verywell

Cancer is a scary diagnosis, and chemotherapy isn't easy. While chemo doesn't work for everyone, it's a tried-and-true therapy that works well for many types of cancers. Your doctors can help guide you through the process, help relieve side effects, and offer you support along your journey. It's important to embrace your support system—including people who are receiving infusions alongside you—as you fight your cancer.

Frequently Asked Questions 

What happens during chemotherapy?

During chemotherapy, you will arrive at an outpatient infusion center, have a brief assessment, and begin your infusion. Infusions usually last several hours, but you do not have to stay overnight. It's a good idea to have someone drive you home afterward.

Can chemotherapy treatment be painful?

Some side effects can cause pain, like neuropathy. This nerve pain can create tingling or numbness in your hands and feet. But not everyone has side effects or neuropathy from chemo, and some people may have mild and fleeting side effects, like nausea or fatigue.

Is chemotherapy required for certain stages of cancer?

Chemotherapy is never required. How you treat your cancer is a decision that is made between you and your doctor. Chemotherapy is generally more effective in earlier stages of cancer. Treatments usually don't work as well when cancer is detected in advanced stages.

How effective is chemotherapy?

Chemotherapy is very effective at killing cells, but how effective it is at fighting your particular cancer is unknown. Chemotherapy's effectiveness varies by cancer type, location, grade, and stage. Talk to your doctor about your specific prognosis for your cancer type and overall health.

10 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cancer Research UK. How chemotherapy works.

  2. BreastCancer.org. Getting a chemotherapy infusion: Step by step.

  3. Cleveland Clinic. Chemotherapy.

  4. MedLinePlus. Types of chemotherapy.

  5. American Society of Clinical Oncology. Understanding chemotherapy.

  6. American Cancer Society. Chemotherapy side effects.

  7. Romiti, A., Cox, M.C., Sarcina, I. et al. Metronomic chemotherapy for cancer treatment: a decade of clinical studies. Cancer Chemother Pharmacol. February 12, 2013;72: 13–33. doi:10.1007/s00280-013-2125-x

  8. National Institutes of Health. Metronomic chemotherapy.

  9. National Institutes of Health. Understanding cancer prognosis.

By Rachael Zimlich, BSN, RN
Rachael is a freelance healthcare writer and critical care nurse based near Cleveland, Ohio.