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About the skin and cancer

Cancer and its treatment can damage the cells of the skin and stop them from working properly. Find out more.

What the skin does

The skin is the largest body organ and has many functions. They include:

  • protecting the inside of the body from damage
  • helping to control body temperature
  • getting rid of some body waste products through sweat
  • protecting the body from infection
  • providing sensation so that we can feel pain, heat, cold and other feelings
  • producing vitamin D

It can also repair itself and grow back when damaged.  

The skin’s layers

The skin has a number of layers. These include:  


The top layers of the epidermis are made of dead cells that contain keratin. Keratin is tough and waxy and helps to toughen the skin so that it can protect the body. 

The epidermis is constantly changing as the top layers rub off and new cells, created underneath, gradually make their way to the surface to replace the lost cells. This process takes about 35 days. 


This layer contains nerve endings, blood vessels, oil glands and sweat glands. It also contains vital proteins collagen and elastin, to make the skin tough and stretchy.

The oil glands are also called sebaceous glands (pronounced seb-ay-shus). They make a substance called sebum. It rises up into the epidermis and keeps the skin moist and waterproof to protect the body.

The thickness of the epidermis and the dermis varies in different parts of the body, from about 2mm to 4mm. For example, the skin on the back is quite thick, with an epidermis and dermis of about 4mm. The skin on the face is much thinner.

Under the dermis is a third layer: the fat layer (hypodermis).

Fat layer (hypodermis or subcutaneous layer)

The layer of fat under the dermis is called the subcutaneous layer. This layer helps to keep us warm and absorbs knocks and shocks. It also contains the hair follicles. Hair grows from the follicles.

Diagram showing the structure of the skin

Factors that affect the skin

What we eat and drink

To keep healthy skin, we need to eat a well-balanced diet. We also need to take in at least 2 litres of fluid a day (about 8 glasses).

We get this fluid from food and drink. You can get dehydrated and your skin can become dry if you don’t have enough fluid. Your skin can’t work properly if it is dry. It won’t be as supple and stretchy. Smoking can make the skin dry and drinking a lot of alcohol can also dry the skin.


As we get older, our skin:

  • gets thinner and less elastic
  • is more fragile and more easily damaged
  • is less able to deal with infections and heal after injury
  • can be drier
  • may react to soaps and cosmetics, changes in temperatures and friction


We need to move and change position so that we don’t put constant pressure on one area of the body. If we can’t move around much, we are at risk of developing sore, red areas on our skin, which can break down.


Many different diseases can affect the skin, including cancers that start in the skin or may spread there from other parts of the body. Other less serious skin conditions, such as eczema and psoriasis, can add to the problems caused by cancer or its treatment. Talk to your doctor about how to manage a skin condition alongside your cancer treatment.

Side effects of cancer treatment

Some cancer drugs can affect the skin, including chemotherapy and biological therapies. They can make the skin:

  • become dry
  • become discoloured - usually darker
  • more sensitive to sunlight
  • break out in rashes or spots, similar to acne


The environment around us

If the environment you are in is hot or cold it can have an affect on your skin. Both can make your skin dry. If it is hot you may sweat more, and this can also have an impact if your skin is more delicate.

How you care for your skin

Keeping your skin clean, dry and moisturised will help to keep it healthy. What you need to do may change depending on the factors above.

Last reviewed: 
11 May 2016
  • Oxford textbook of palliative medicine (3rd Edition)
    Editors Doyle D, Hanks G, Cherny M, Calman K
    Oxford University Press
    ISBN 0 19 856698 0

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