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About skin cancer


Introduction to skin cancer

In this section, you can find information on:

  • The skin and skin cancer
  • The treatment options available
  • Specific information on brachytherapy and the procedure
  • The healthcare professionals involved in delivering brachytherapy
  • Potential benefits of brachytherapy
  • Potential side-effects to consider
  • Frequently asked questions
  • Useful questions to ask your doctor


About the skin

The main purpose of the skin is to protect the body’s internal organs from damage and infection, and to regulate body temperature.1

The skin is made up of two layers of cells. The ‘epidermis’ layer is nearest to the surface of the skin and the ‘dermis’ is the layer underneath.

The epidermis layer contains:1

  • Squamous cells – flat cells on the surface.
  • Basal cells – round cells under the squamous cells.
  • Melanocytes – produce a pigment called melanin, which gives skin its color.


skin


What is skin cancer?

Skin cancer occurs when abnormal cells develop within the skin cells.

There are three main types of skin cancer, corresponding to the different types of cells found in the epidermis.2

basal cell carcinoma
  • Basal cell carcinoma – the most common form of skin cancer. Most basal cell cancers are slow growing.
  • Squamous cell carcinoma – the second most common type of skin cancer.
  • Malignant melanoma – is far less common than basal cell or squamous cell skin cancer.

Excessive exposure to sun is the main cause of most skin cancers. Most basal and squamous cell skin cancers occur on sun-exposed sites, such as the head and face.



Risk factors

The following risk factors are known to increase the risk of developing skin cancer:3

  • Sun exposure – the ultraviolet rays from the sun can damage the skin. Excessive exposure to the sun over several years increases the risk of developing skin cancer later in life.
  • Skin color – people with naturally darker skin have greater levels of melanin in their skin. This protects the skin against the ultraviolet rays. People with darker skin are at a lower risk of skin cancer than people with fairer skin.
  • Other risk factors include chronic skin injuries, such as burns, scars, long standing sores and areas of skin damaged by chemicals.


What tests are used to confirm a diagnosis?

As most skin cancers occur on sun-exposed sites, they are usually noticed at a very early stage. They appear as a small lump on the skin and can be smooth and waxy, or scaly and crusty.4

If you notice any unusual looking growths on the skin it is important to talk to your healthcare professional. If they suspect that you might have skin cancer, you will be referred to a specialist for further tests to confirm a diagnosis.

A biopsy of the growth can reveal if it is cancerous or not. This involves a small sample of tissue being taken for examination under a microscope.


How do I know how advanced the cancer is?

Terms such as ‘staging’ and ‘grading’ are used by healthcare professionals to describe the level of progression of the cancer and help inform which treatment options might be best.5

The various stages of skin cancer are summarized below:


Type Stage Description
Carcinoma in situ 0 Cancer cells are only present in the epidermis layer of the skin
Early skin cancer 1 The cancer is less than 2cm in size.
2 The cancer is more than 2cm in size.
3 The cancer has started to spread to tissues under the skin.
Advanced (metastatic) skin cancer 4 The cancer has advanced to other parts of the body. Advanced skin cancer is very rare for squamous cell and basal cell carcinomas.


References

  1. National Cancer Institute. Available at: http://www.cancer.gov/cancertopics/wyntk/skin/page2. Accessed 2 February 2011.
  2. National Cancer Institute. Available at: http://www.cancer.gov/cancertopics/wyntk/skin/page4. Accessed 2 February 2011.
  3. National Cancer Institute. Available at: http://www.cancer.gov/cancertopics/wyntk/skin/page5. Accessed 2 February 2011.
  4. National Cancer Institute.Available at: http://www.cancer.gov/cancertopics/wyntk/skin/page8. Accessed 2 February 2011.
  5. National Cancer Institute. Available at: http://www.cancer.gov/cancertopics/wyntk/skin/page9. Accessed 2 February 2011.
Page last updated on 19 April 2011.

Skin cancer

 

Cancer types

 



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