MouthMade

What causes oral mucositis?

Chemo- and radiotherapy work by preventing the growth of new cancer cells by killing rapidly dividing cancer cells that are already there. Unfortunately, these treatments can?t tell the difference between dividing healthy cells and dividing cancer cells. The side effects of therapy, including oral mucositis (OM), happen when healthy dividing cells are also killed. The combination of chemo- and radiotherapy increases the risk of developing severe oral mucositis. The symptoms of oral mucositis also tend to get worse the longer the radiotherapy treatment lasts.

During radiotherapy for head and neck cancer or Hematopoietic Stem Cell Transplant (HSCT) (sometimes called a Bone Marrow Transplant [BMT]), the beam of radiation passes near and in the mouth. Normally healthy cells in the mouth quickly divide and replace surface cells with new cells. However, radiotherapy kills these dividing cells meaning the surface cells cannot be replaced, causing ulcers to form.

Chemo- and radiotherapy to the head and neck damage the glands in the mouth that produce saliva (spit), causing the mouth to be drier than normal. A dry mouth means the natural lubrication saliva provides for eating is much less. This makes it difficult to swallow and the mouth is more likely to be damaged by hard food that is normally washed away by saliva.

The type, dosing and duration of chemotherapy used to treat the cancer will affect the likelihood of developing oral mucositis. There are many types of chemotherapy that are known to cause oral mucositis. Some of these therapies are listed below:¹

• 5-fluorouracil
• methotrexate
• doxorubicin
• etoposide
• melphalan
• cytosine arabinoside
• cyclophosphamide

All radiotherapy that passes in and near the mouth is very likely to cause oral mucositis.

Please note that there are other types of chemotherapy that may cause oral mucositis. Always check with your doctor or nurse if your treatment might cause oral mucositis.

Always speak to your doctor or nurse if you are worried about oral mucositis.

Download an oral mucositis patient factsheet for your own information and why not print out a nurse factsheet to give to your nurse.

1. Pico J-L et al. The Oncologist 1998;3(6):446–451.