Skin Cancer

Skin cancer is the most common form of cancer in Ireland. There are many different types, but the most common are Basal Cell Carcinoma, Squamous Cell Carcinoma and Malignant Melanoma. Each year, skin cancer affects approximately 7,000 people for the first time. A large proportion of these will go on to develop a second, third or more skin cancers. Once you have had one type of skin cancer, you are at a higher risk of developing other forms of the disease. There are many other forms of skin cancer, most of which are rare. Thankfully, most skin cancers are not life-threatening. Even the most dangerous form, Malignant Melanoma, is curable if caught in the early stages.  

The most important cause of skin cancer is the damage caused by the sun’s ultraviolet radiation (sunburn) and overall sun exposure.  Also important are your skin type and how it reacts to the sun: fair/red hair, blue/green eyes, freckles and the ability to tan. In addition, some skin cancers have a genetic basis.

The body’s organs and tissues are made up of building blocks called cells. In healthy tissue, cells replace or repair themselves when they get damaged or are worn out. Different skin cancers occur when skin cells do not behave as normal and continue to grow even when there is no need. If the cancerous cells continue to grow locally or are in the early stages and have not spread, the cancers do not result in serious disease or death but can cause disfigurement. If, however, the cancer cells spread elsewhere in the body, death can result. That is why identifying skin cancer early is so important.

There are certain risk factors that can increase your chance of developing skin cancer. These include:

  • Exposure to ultraviolet radiation (UVR) during childhood and adolescence.
  • Repeated exposure to UVR throughout life (e.g. working or recreation outside).
  • Episodes of severe sunburn.
  • A light complexion (red or fair hair, blue or green eyes and skin that burns easily, freckles and does not tan).
  • Older age.
  • A previous skin cancer (non-melanoma skin cancer).
  • A personal or family history of melanoma.
  • A large number of moles.
  • Unusual types of moles.
  • Immunosuppressed (including organ transplant recipients).

St. James’s Hospital is one of the national skin cancer diagnostic centres and one of the eight national treatment centres. It is the only centre in Ireland performing a specialized type of surgery for high-risk skin cancers called Mohs Micrographic Surgery.  

Common Types of Skin Cancer

Actinic Keratosis–Sun Damage Spots

  • Rough, red or pink scaly patches on sun-exposed areas of the skin such as the face, hands and upper chest.
  • Warning signs of sufficient sun to cause a skin cancer.
  • Possible precursor to Squamous Cell Carcinoma.

Basal Cell Carcinoma

  • Raised, pink, waxy bumps that may bleed following minor injury.
  • Scaly red lesions that do not heal.
  • Small raw patches of skin that break down and do not heal.
  • May have superficial blood vessels.

Squamous Cell Carcinoma

  • Dull red, rough, scaly raised skin lesions. May be tender or painful.
  • Appears on sun-exposed areas (head, neck, ears, lips, back of the hands and forearms).
  • Squamous Cell Carcinoma tumors can grow very rapidly or very slowly.
  • Squamous Cell Carcinoma tends to be more invasive and more aggressive in transplant patients.
  • Is slow growing, invades locally and rarely spreads. (Can spread in about 2% of patients).


  • Cancer of tanning pigment (melanin) cells.
  • Brown/black/multiple colours.
  • Irregularly coloured, with irregular border and/or shape or irregular edges.
  • Can be slow or fast growing.
  • Can resemble a mole but looks different to your other moles, the so-called “ugly duckling sign”.
  • Prognosis depends on how deep into the skin the tumour has invaded.