About the skin and cancer

The skin is the largest body organ. Cancer and its treatment can damage the skin cells and stop them from working properly. Knowing more about how the skin works and what may affect it can help you care for it better.

What the skin does

The skin 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 several layers. These include:  

Epidermis

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 constantly changes 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 28 days. 

Dermis

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 from bacteria on the skin.

The thickness of the epidermis and the dermis varies in different body parts. For example, the skin on the back is quite thick, compared to the skin on the face, which is much thinner.

Under the dermis is a third layer called the subcutaneous layer.

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. Vitamins and minerals from fresh fruit and vegetables, as well as protein, are important for healthy skin. We also need to drink 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.

Age

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

Activity

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.

Illness

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.

UV radiation

Too much UV radiation from the sun or sunbeds can damage the DNA in our skin cells and cause skin ageing or skin cancer. DNA tells our cells how to function. If enough DNA damage builds up over time, it can cause cells to start growing out of control, which can lead to skin cancer.

The environment around us

If the environment you are in is too hot or cold, it can affect your skin.

Low temperatures, with low humidity, can cause the skin to be dry, itchy and more sensitive. Low humidity means there is a small amount of water vapour in the air.  

Hot temperatures can cause dry skin, increased sweating and higher levels of sebum production in the skin. Too much sebum can cause problems such as acne. Sweat trapped in sweat glands can cause heat rash in the summer.

Side effects of cancer treatment

Chemotherapy, targeted drugs or immunotherapy

Some cancer drugs can affect the skin and nails. This includes chemotherapy, targeted drugs or immunotherapy. They can make the skin:

• become dry and itchy
• become discoloured - usually darker
• more sensitive to sunlight
• break out in rashes or spots, similar to acne
• sore such as on the palms of the hands and soles of the feet 

Other changes include nail changes such as:

• nails becoming brittle and thin
• infection around the fingernails or toenails

Radiotherapy

Radiotherapy treatment can affect your skin. Your skin may become:

• sore
• redder or darker than usual 
• dry and flaky
• blistered

How to care for your skin

Keeping your skin clean, hydrated, dry and moisturised will help to keep it healthy.

Make sun protection part of your daily skincare. Sun protection can help to prevent wrinkles, age spots, and skin cancer. Try to seek shade, wear sun protective clothing, or apply sunscreen to all skin not covered by clothing when out in the sun for long hours.

What you need to do may change depending on the above factors affecting the skin.