Chemotherapy of Cancer


One of the main treatments for cancer is chemotherapy – treatment through the use of medication. This often involves combinations of chemicals and can be used in a number of ways:

  • To attempt to completely eradicate the cancer – curative chemotherapy.
  • To improve the quality of life for patients with a terminal diagnosis, relieving them of symptoms – palliative chemotherapy.
  • To combine with other treatments to make them more effective, for example chemoradiation - a combination of chemotherapy and radiation therapy.
Often, chemotherapy is given intravenously over a period of time so as to avoid damaging healthy cells, but in some circumstances it is injected into the hepatic artery leading to the liver where the cytotoxic drugs can be digested.

In other cases, the cytotoxic drugs can be consumed orally such as with lomstine (used to treat Hodgkin’s disease resistant to conventional therapy, malignant melanoma and certain solid tumours).

There are a number of factors that are used to determine the dosage of cytotoxic drugs:

  • Body surface area or body weight – determines the concentration of the drug that each cell receives.
  • The patient’s neutrophil count – affecting their ability to fight disease. If the chemotherapy kills the patient’s white blood cells (causing severe immunodeficiency), they are significantly more susceptible to disease so dosage and time between treatments must be carefully calculated.
  • The patient’s renal and hepatic function – impaired function in the kidneys or liver will affect how long the drug remains in the body. The longer the drug stays in the body, the worse the damage to healthy cells and the greater the risk of side effects.
  • Whether or not the drug is used in combination as combinations often have an enhanced effect on both the cancer and the cells surrounding the cancer which are also affected by the drugs. Notably, combination drugs are met with reduced drug resistance.
  • Any other medication that the patient is taking that might contraindicate the drug.

Side Effects
There are a number of side effects associated with the use of cytotoxic drugs, which by definition are toxic to living cells. The side effects are often individual to the patient, and can be affected by anything from allergies to medication that they are taking. Common side effects of chemotherapy include alopecia, vomiting, nausea, oedema and mucositis.

Combinations
A number of cytotoxic drugs are combined with folinic acid in order to help rebuild cells after they have been destroyed, before the next round of chemotherapy.

To treat prostate cancer, combinations often use oestrogen in order to stop the prostate from growing so that the normal rate of cell division is reduced therefore reducing the rate of any cancer spreading.

Busulfan in combination with cyclophosphamide is used as a conditioning treatment before haematopoietic stem cell transplantation. Frequent blood tests are necessary because excessive myelosuppression may result in irreversible bone marrow aplasia.

 Thank you for reading, I hope you found this article informative.
By Louis Lane

 Sources:
https://www.nhs.uk/conditions/chemotherapy/

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