What is chemotherapy?

What is chemotherapy?

Chemotherapy is a type of cancer treatment in which one or more anticancer drugs are used as part of a standard treatment regimen. Chemotherapy can be given curatively, that is, to provide complete healing, or it can be used to prolong life or control symptoms. Normally, cells in the body multiply, grow and die in a controlled manner. Cancer cells continue to multiply and grow uncontrollably. Chemotherapy works by killing cancer cells, preventing their spread and slowing their growth. However, it also damages healthy body cells, causing side effects. But chemotherapy can prolong a person’s life and save the patient from cancer.

What is chemotherapy?

Chemotherapy is a cancer treatment method used in modern medicine, in which various drugs are given to the patient to kill cancer cells. Unlike radiotherapy or surgery that targets specific areas, chemotherapy is a systemic treatment method that is effective on the whole body. The drugs used in chemotherapy treatment are especially effective on rapidly dividing and multiplying cells such as cancer cells. However, while it destroys cancer cells, it also damages some fast-producing healthy body cells, such as skin, hair, gut and bone marrow cells. The cause of various side effects such as hair loss, nausea and vomiting seen in the treatment is due to damage to healthy body cells.

How is chemotherapy given? 

Chemotherapy can be given to a patient in many different ways. Chemotherapy drugs have oral tablet forms, as well as forms that can be administered intravenously or directly into the abdominal cavity. The routes of administration of chemotherapy drugs can be listed as follows;

  • Intramuscular or subcutaneous injection:  In this way, drugs are administered directly into the muscle from the hip, thigh or arm, or subcutaneously from the adipose tissue of the arm, leg or abdomen.
  • Intra-arterial injection:  Drugs are given directly into the artery feeding the cancer. The application is made through a needle, or a soft thin catheter.
  • Intraperitoneal:  Chemotherapy Drugs are delivered into the peritoneal cavity, which includes organs such as the liver, intestines, stomach, and ovaries. It can be given during surgery or through a special tube placed in the abdomen by the doctor.
  • Intravenous injection:  Chemotherapy is given directly into a vein.
  • Topical:  Medicines are rubbed into the skin in the form of a cream.
  • Oral:  Medicines are taken orally in pill or liquid form.

What are the side effects of chemotherapy?

Cancer cells tend to grow and multiply rapidly, and chemotherapy drugs kill fast-growing cells. However, since these drugs act systemically, they also damage fast-growing normal, healthy body cells. Damage to healthy cells causes some side effects. Side effects may not always be as bad as expected, but many people are seriously concerned about the side effects of chemotherapy and cancer treatment. Normal cells most likely to be damaged by chemotherapy include:

  • blood-forming stem cells in the bone marrow
  • cells in hair follicles
  • cells in the mouth
  • digestive system cells
  • cells of the reproductive system

Some chemotherapy drugs can also damage the heart, kidneys, bladder, lungs, and nervous system. Sometimes other drugs may be recommended along with chemotherapy to help protect your body’s normal cells. Additional medications given help alleviate side effects. Some of the most common side effects caused by chemotherapy include:

  • Tiredness
  • hair loss
  • Easy bruising and bleeding on the skin
  • Weakness of the immune system and susceptibility to infections
  • Anemia (Low red blood cell count)
  • Shortness of breath
  • Nausea and vomiting
  • Anorexia
  • Constipation
  • Diarrhea
  • Mouth and tongue sores:  Some patients have painful sores in their mouths 1-2 weeks after some chemotherapy regimens. The severity of the pain can vary, and the wounds can sometimes bleed or become infected.
  • Generalized pain:  A generalized pain, including chronic muscle pain, headaches, and other pains, is common after chemotherapy.
  • pain while swallowing
  • Throat ache
  • Neuropathy:  Nervous pain caused by damaged nerve cells. It usually affects the hands and feet. It causes tingling, numbness, and unusual electrical sensations in addition to pain. Some people experience muscle weakness and ringing in the ears.
  • Skin dryness and skin discoloration
  • Skin rashes:  Rashes may cause severe itching.
  • Swelling in hands and feet
  • Urinary and bladder problems
  • kidney problems
  • heart health problems, such as unusually low blood pressure
  • weight loss
  • concentration problems
  • Personality and mood changes, such as depression, aggression, or anxiety
  • Libido and sexual function problems
  • Infertility

In rare cases, side effects that develop during chemotherapy can be permanent. For example, permanent nerve damage may develop, causing chronic numbness and tingling in the hands and feet. The aim of treatment is to give the maximum dose of drugs that can cure cancer while keeping the side effects to a minimum. Doctors also try to avoid using multiple drugs with similar side effects at the same time. Points to know about chemotherapy-related side effects;

  • Medications do not cause every side effect in every person, and some people may experience a small number of side effects.
  • The severity of side effects varies greatly from person to person.
  • The doctor may prescribe various medications to prevent some side effects before they occur.
  • Some chemotherapy drugs cause long-term side effects, such as heart or nerve damage or infertility. However, many patients may not experience such chronic side effects.
  • Although chemotherapy drugs can cause serious side effects, the profit and loss rate to be obtained because they destroy cancer cells should be well weighed.

What are chemotherapy drugs? 

There are dozens of chemotherapy drugs used to treat cancer. They are often divided into groups according to how they work and what they do. Each group of drugs destroys or shrinks cancer cells in a different way.

Alkylating agents 

Some drugs prevent cancer cells from replicating themselves by damaging their DNA. Known as alkylating agents, this group is one of the oldest chemotherapy drugs. It is used in the treatment of many different types of cancer such as leukemia, lymphoma, Hodgkin lymphoma, multiple myeloma, sarcoma. They are also preferred in the treatment of some breast, lung and ovarian cancers. Examples of alkylating agents are cyclophosphamide, melphalan, and temozolomide. These drugs can damage the bone marrow as well as bad cells. This can cause leukemia years later. Platinum group drugs such as carboplatin, cisplatin or oxaliplatin, which are alkylating agents, have a lower risk of causing leukemia.


Chemotherapy drugs known as antimetabolites stop growth by interfering with the normal metabolism of cells. This group of drugs is commonly used to treat leukemia and breast, ovarian and bowel cancers. Antimetabolites include 5-fluorouracil, 6-mercaptopurine, cytarabine, gemcitabine, and methotrexate.

Mitosis inhibitors 

Medicines called mitosis inhibitors prevent cancer cells from multiplying by dividing. It may also prevent the body from producing the proteins that cancer cells need to grow. This group of drugs can be prescribed for types of breast and lung cancers and  bone marrow cancers  such as myeloma, leukemia and lymphoma. Mitosis inhibitors include docetaxel, estramustine, paclitaxel, and vinblastine.

Topoisomerase inhibitors

Chemotherapy drugs called topoisomerase inhibitors attack enzymes that help cancer cells divide and grow. This group of drugs includes drugs called etoposide, irinotecan, teniposide and topotecan and is used in the treatment of some types of leukemia, lung, ovarian and bowel cancer. Some of these drugs increase a patient’s chance of developing a second cancer several years after treatment.


Anthracyclines, similar to topoisomerase inhibitors, attack enzymes found in the DNA of cancer cells that help them divide and grow. Some of these drugs, also known as antitumor antibiotics, are actinomycin-D, bleomycin, daunorubicin, and doxorubicin. These can cause damage to the heart or lungs if used in high doses.

What should be considered after chemotherapy? 

Oral care after chemotherapy is extremely important. Chemotherapy drugs can cause dry mouth and painful sores. Dryness and sores can cause an increase in bacteria in the mouth and an infection. Infections in the mouth can spread to other parts of the body. What can be done for oral and tongue care;

  • Teeth and gums should be brushed 2 to 3 times a day, for 2 to 3 minutes each time, with a soft-bristled toothbrush.
  • If possible, a fluoride toothpaste should be preferred.
  • Floss gently once a day, without damaging the gums.
  • Efforts should be made to avoid infection for a year or more after chemotherapy. For this, the patient should pay attention to what he eats and drinks, and pay attention to hygiene. Hands should be washed with soap and water before and after meals, after using the toilet and when returning home from outside. Contact should not be made with infected individuals.

Continuing to do sports, eating a healthy diet with adequate protein and calories, avoiding smoking and alcohol, and strictly following your doctor’s recommendations are extremely important for the post-chemotherapy period, as in any case.