Skin Cancers


Skin cancers are the most common cancers in Australia because of our predominantly Caucasian population living in a subtropical climate and our love for the outdoors. Early detection and treatment are most important in minimizing complications and deaths due to skin cancers. Regular skin checks are essential for individuals at increased risk of skin cancers such as those with outdoor occupations or significant recreational sun exposure, previous use of tanning beds and solarium, family history of melanoma or patients with previous skin cancers.

It is essential to seek medical attention if you develop persistent symptoms (itching, irritation, bleeding or pain) in your skin spots or if your skin spot undergoes significant change. Self-diagnosis is not recommended since it requires prolonged training and experience to detect these cancers. Dermatologists are trained to be experts at diagnosis and treatment of skin cancers.

The great majority of skin cancers including melanomas are cured if detected early and appropriately treated. Definitive treatment of skin cancers usually requires surgery. However, non-surgical treatment such as creams (imiquimod, 5-fluorouracil), photodynamic therapy and cryotherapy can be used in some types of early and less aggressive skin cancers. Radiotherapy may be used in elderly patients who are otherwise unable to tolerate surgery.


Melanoma accounts for less than 5% of skin cancers but is responsible for about 80% of skin cancer deaths. Risk factors for melanoma include:

  • Family history of melanoma especially history of multiple melanomas or melanoma at a young age (<50 yrs)
  • High mole count
  • Presence of atypical moles
  • Pigmentation traits of fair skin, blue eyes, red hair and freckles
  • Sun exposure is the only known environmental risk factor. History of sunburns during childhood is most important
  • Exposure to artificial sources of ultraviolet radiation such as tanning beds or therapeutic PUVA. However, studies have found that narrow-band UVB phototherapy does not increase the risk of melanoma

About three quarters of melanomas arise in normal skin while the remainder arise in existing moles. The most common presentation is a pigmented lesion that is irregular in shape and/or displays multiple colours. It becomes progressively more irregular with time and changes more rapidly than expected for moles. About 15% of melanomas present as a rapidly growing nodule that may ulcerate or bleed. These nodular melanomas are very aggressive and medical attention must be sought immediately. Less common presentations include melanomas affecting the soles, nail unit, eyes or mucous membranes of the mouth or genitalia.

Treatment of melanomas is primarily wide local excision. The required surgical margin is dependent on the melanoma depth as indicated by its Breslow thickness. Regular follow-up is recommended to detect for recurrences as well as for other skin cancers. Treatment of advanced metastatic melanomas is complex and requires a multi-disciplinary team of surgeons, medical and radiation oncologists and other specialists.

Basal cell carcinoma (BCC)

Basal cell carcinoma is the most common type, accounting for about 70% of skin cancers. The majority of BCCs are located on the head and neck. Most BCCs are indolent and grow slowly, however more advanced lesions can ulcerate, bleed or cause destruction of the affected structure such as the nose, ear, eye or lip. More aggressive variants of BCC may extend significantly deeper and/or wider than can be appreciated with visual examination. They may also extend to involve structures beneath the skin such as blood vessels, nerves, muscle or even bone.

Non-surgical treatment such as topical imiquimod (Aldara), cryotherapy or photodynamic therapy can be used on small (<2 cm diameter) superficial BCCs on low-risk sites. Surgical treatment is generally required for other BCCs. Radiotherapy is used in patients with contraindications to surgery or in whom surgery would cause significant disfigurement.

Bowen disease

Bowen disease is also known as squamous cell carcinoma (SCC) in situ. It is a type of cancer that is limited to the top layer of skin and has not invaded deeper. It usually manifests as a red and scaly patch on sun-exposed skin. However, it may also affect the nail unit or sun-protected sites such as the ano-genital area. Bowen disease on hair-bearing areas can extend deeper into the skin as the cancer cells may invade and track down the hair follicles. Most Bowen disease lesions are treated by cryotherapy, curettage or non-surgical treatments. Surgical excision is generally recommended for thicker lesions likely to also contain invasive SCC, lesions with extension down hair follicles or lesions involving the nail unit.

Squamous cell carcinoma (SCC)

Squamous cell carcinoma is the second most common type of skin cancer. The great majority of SCCs are caused by chronic sun exposure. SCCs occurring on sun-protected sites may be secondary to chronic inflammation, scars or radiation damage. SCCs usually form localized, slightly tender thickening of the skin. Features of a more aggressive lesion include ulceration/bleeding, lesions larger than 2 cm, SCC recurring after previous treatment, and lesions occurring on certain sites such as the ear, nose or lip. These more aggressive SCCs have a greater potential for spread to the lymph nodes or distant sites.

Surgical excision is the recommended treatment for SCCs. Radiotherapy can be used in elderly patients unable to tolerate surgery. Small and low-risk SCCs may also be treated by curettage and cautery.

Skin cancer prevention

Ultraviolet (UV) radiation is the component of sunlight that causes skin cancer. It should be noted that UV radiation cannot be seen or felt such that the UV index can be very high even on a cloudy day. Protection from the sun is by far the most important preventative measure against skin cancers. Critically, sun protection practices must start at a young age since sunburns are more damaging in children.

Important components of sun proctection practice include:

  • Seeking shade whenever possible. This may require some planning such that work or activities are under a shade or indoors during the middle part of the day. Reflective surfaces such as water, sand or snow should also be avoided. Tinted windows are recommended for those spending more prolonged time in vehicles.
  • Personal protective measures when sun exposure is not avoidable and the UV index is 3 or above. These measures must be applied ‘head to toe’ and include a broad-brimmed hat, sunglasses, long-sleeved shirt with collar, pants and closed shoes. Broad-spectrum SPF 50+ sunscreen is to be applied to all uncovered skin.

Acitretin (Neotigason) has been used to reduce the high burden of skin cancers, especially squamous cell carcinomas, in organ transplant recipients who are immunosuppressed. The use of acitretin needs to be supervised by a dermatologist due to a large number of potential side effects. Recent studies have reported encouraging result of high-dose nicotinamide in reducing the development of skin cancers. However, these have only been short-term studies. More data and results of studies over the longer term are needed.

Early detection and treatment is the other important aspect of skin cancer prevention since almost all skin cancers can be cured if detected early. Regular skin checks are recommended for individuals with increased risk of skin cancers.