Chemotherapy involves taking medications that kill cancer cells and other cells in your body that replicate quickly. It treats many different types of cancer in all stages.

Chemotherapy is one of the most common cancer treatments. It’s often the primary treatment for cancer either by itself or combined with other treatments such as:

  • surgery
  • radiation therapy
  • immunotherapy
  • targeted therapy drugs

Whether your doctor recommends chemotherapy and the type of chemotherapy they recommend depends on factors such as:

  • the type and subtype of cancer
  • the stage of the cancer
  • how quickly the cancer is expected to grow
  • your age and overall health

Read on to learn more about how chemotherapy treats cancer.

Chemotherapy treats all stages of cancer. The goal for early-stage cancer is often to cure the cancer. Chemotherapy for cancer spread to distant areas is often palliative.

Doctors often use the American Joint Committee on Cancer’s TNM staging system to stage cancer from 1–4.

This staging system is different for each type of cancer. In general, stage 1 cancers are limited to one organ, and stage 4 cancers have spread extensively or to distant locations.

Here’s an example of how chemotherapy can treat non-small cell lung cancer by stage:

StageChemotherapy use
1• a clinical trial of chemotherapy following surgery
2• surgery followed by chemotherapy
• chemotherapy followed by surgery
3A that can be removed surgically• chemotherapy followed by surgery
• chemotherapy and radiation therapy followed by surgery
immunotherapy and chemotherapy followed by surgery
• surgery followed by chemotherapy and radiation therapy
3A that can’t be removed surgically• chemotherapy and radiation therapy
• chemotherapy and radiation therapy followed by immunotherapy
3B and 3C• chemotherapy followed by radiation therapy
• chemotherapy with radiation therapy, possibly with an increasing dose of radiation
• chemotherapy and radiation with immunotherapy before or after
• a clinical trial of chemotherapy and radiation therapy followed by a radiosensitizer
Stage 4 or relapsed• a combination of chemotherapy medications
• a combination of chemotherapy medications and targeted therapy
• a combination of chemotherapy drugs followed by more chemotherapy

Learn more about the types of chemotherapy drugs.

The first tumor cured with chemotherapy in a human occurred in 1953. Since then, chemotherapy has become a critical part of treatment for most cancers.

Healthcare professionals often administer chemotherapy drugs intravenously (IV) over minutes to hours in cycles that usually last from 2–6 weeks.

On certain days of the cycle, you receive chemotherapy drugs. On the other days, you recover.

Learn more about the duration of chemotherapy.

You may receive chemotherapy in the following situations:

Neoadjuvant chemotherapy

Healthcare professionals administer neoadjuvant chemotherapy before your primary treatment to shrink cancer cells and make your cancer easier to treat. For example, before breast cancer surgery, you may receive neoadjuvant:

Adjuvant chemotherapy

Healthcare professionals administer adjuvant chemotherapy after the primary treatment. It can potentially remove cancer cells missed by the primary treatment and improve your chances of survival.

Concurrent chemotherapy

Concurrent chemotherapy is the combination of chemotherapy with another treatment. Doctors often combine it with radiation therapy. The combination of these two treatments is called chemoradiation.

Palliative chemotherapy

Palliative treatments aim to reduce your symptoms and prolong your life. Your doctor may recommend palliative chemotherapy if your cancer has spread to distant organs and isn’t considered curable.

Ways chemotherapy drugs are administered

Chemotherapy drugs are often administered through an IV, but other ways they’re administered include:

  • orally
  • through intramuscular injections
  • through subcutaneous injections
  • through injections into your spinal canal
  • through a cream applied to your skin
  • directly into an organ such as your bladder

Undergoing chemotherapy can be a stressful experience, and it can help to have people around you who can support you.

Living alone while undergoing chemotherapy can raise challenges, such as making it more difficult to get home from the hospital and not having anybody to help with daily chores.

Here are some ways you may be able to make your treatment easier if you’re living alone:

  • Let your healthcare team know that you live alone so they can support you.
  • Communicate with family or friends about your treatment schedule and let them know if there’s anything they can do to help you.
  • Ask friends and family if you can use them as emergency contacts.
  • Consider joining a support group to get into contact with other people in a similar situation.
  • Try calling 311, searching online, or asking your healthcare team to see if there are volunteer homemaking services in your area.
  • Make sure you have enough food and other supplies in your home before starting your treatment cycle.
  • Write down your treatment schedule and when you need to take your medications.
  • Accept help when offered.

Chemotherapy can treat all stages of cancer. It may be the primary treatment to try to cure your cancer.

Healthcare professionals may also administer it before, at the same time, or after other treatments to improve their effectiveness.

Your healthcare team can help you decide whether chemotherapy is right for you. Undergoing chemotherapy can be very stressful, but it can also be lifesaving.