The term chemotherapy is used to describe cancer-killing medicines. Chemotherapy may be used to:
Cure the
Shrink the cancer
Prevent the cancer from spreading
Relieve symptoms the cancer may be causing
HOW CHEMOTHERAPY IS GIVEN
Depending on the type of cancer and where it is found, chemotherapy medicines may be given different ways, including:
Injections or shots into the muscles
Injections or shots under the skin
Into an artery
Into a vein (
, or IV) -- most common method
Pills taken by mouth
Shots into the fluid around the spinal cord or brain
When chemotherapy is given over a longer period, a thin catheter can be placed into a large vein near the heart. This is called a central line. The catheter is placed during a minor surgery.
There are many types of catheters, including:
Central venous catheter
Central venous catheter with a port
-- this is the most common catheter used for chemotherapy
Percutaneously inserted central catheter (PICC)
A central line can stay in the body for a long period of time. It will need to be
on a periodic basis to prevent blood clots from forming inside the central line.
Different chemotherapy medicines may be given at the same time or after each other. Radiation therapy may be received before, after, or during chemotherapy.
Chemotherapy is most often given in cycles. These cycles may last 1 day, several days, or a few weeks or more. There will usually be a rest period when no chemotherapy is given between each cycle. A rest period may last for days, weeks, or months. This allows the body and blood counts to recover before the next dose.
Often, chemotherapy is given at a special clinic or at the hospital.
DIFFERENT TYPES OF CHEMOTHERAPY
The
different types of chemotherapy
include:
Standard chemotherapy, which works by killing cancer cells and some normal cells.
, which targets a specific part of cancer cells.
, which uses the immune system to attack cancer cells.
SIDE EFFECTS OF CHEMOTHERAPY
Because these medicines travel through the blood to the entire body, chemotherapy is described as a bodywide treatment.
As a result, chemotherapy may damage or kill some normal cells. These include bone marrow cells, hair follicles, and cells in the lining of the mouth and the digestive tract.
When this damage occurs, there can be side effects. Some people who receive chemotherapy:
Are more likely to have infections
Become tired more easily
Feel pain or numbness from nerve damage
Have a
, mouth sores, or
Have a
Have an upset stomach, vomiting, or diarrhea
Lose their hair
Have problems with thinking and memory ("chemo brain")
Side effects of chemotherapy depend on many things, including the type of cancer and which medicines are being used. Each person reacts differently to these medicines. Some newer chemotherapy medicines that better target cancer cells may cause fewer or different side effects.
Your health care provider will explain what you can do
to prevent or treat side effects. These measures include:
Being careful with pets and other animals to avoid catching infections from them
Eating enough calories and protein to keep your weight up
Preventing bleeding, and what to do if bleeding occurs
and
safely
Washing your hands often with soap and water
You will need to have follow-up visits with your provider during and after chemotherapy. Blood tests and imaging tests, such as x-rays,
,
, or
scans will be done to:
Monitor how well the chemotherapy is working
Watch for damage to the heart, lungs, kidneys, blood, and other parts of the body
Cancer chemotherapy; Cancer drug therapy; Cytotoxic chemotherapy
Collins JM. Cancer pharmacology. In: Niederhuber JE, Armitage JO, Kastan MB, Doroshow JH, Tepper JE, eds. Abeloff's Clinical Oncology. 6th ed. Philadelphia, PA: Elsevier; 2020:chap 25.
Doroshow JH. Approach to the patient with cancer. In: Goldman L, Cooney KA, eds. Goldman-Cecil Medicine. 27th ed. Philadelphia, PA: Elsevier; 2024:chap 164.
National Cancer Institute website. Chemotherapy to treat cancer.
www.cancer.gov/about-cancer/treatment/types/chemotherapy
. Updated May 15, 2025. Accessed May 26, 2026.
Updated by: Warren Brenner, MD, Oncologist, Lynn Cancer Institute, Boca Raton, FL. Review provided by VeriMed Healthcare Network. Also reviewed by David C. Dugdale, MD, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.