About the skin and cancer

Cancer and its treatment can damage the cells of the skin and stop them from working properly. There are different things you can do to prevent this from happening. 

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
  • sweat glands
  • 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 called 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, which hair grows from.

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 which is 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 and drinking a lot of alcohol can also make the skin dry.


As we get older, our skin:

  • becomes thinner
  • has less elasticity
  • is more fragile
  • gets more easily damaged
  • is less able to deal with infections and heal after injury
  • can become 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. This includes cancers that start in the skin or cancers which may have 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


Radiotherapy treatment can affect your skin, making it sore and look redder or darker than usual. 

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, which can affect you even more if your skin is delicate.

How you care for your skin

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

Last reviewed: 
14 Feb 2019
  • The human body book (2nd edition)
    Steve Parker
    DK, 2013
    ISBN 9781409316695

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