Risk Factors

What are the risk factors?

A risk factor is a behaviour, substance or condition that increases the risk of developing cancer. Some people are more likely to develop melanoma; it is often diagnosed slightly more often in men than in women [21]. Risk factors include [22][23]:

  • Ultraviolet radiation (UVR) – UVA and UVB rays are both dangerous to the skin and can cause skin cancers, including melanoma
  • Excessive exposure to UV from the sun or sunbeds – Tanning or sunbeds increase your exposure to UV rays, thus raising your risk of developing melanoma and other skin cancers
  • The number of moles – Moles occur when melanocytes grow together in a group, most are harmless but the higher the number the more risk you have of melanoma
  • Atypical moles – An atypical mole, or dysplastic nevus, look different from normal moles. Atypical moles are often larger than 6 mm and have different colours which range from pink to dark brown
  • A history of blistering sunburns – People who have had one or more blistering sunburns during childhood or adolescence are at a higher risk of developing melanoma
  • A fair complexion – People with a fair complexion are at higher for skin cancers–as they have less pigment, or melanin, in their skin; experts think that melanin protects the skin from UVR
  • A close personal history of melanoma or other skin cancers – Individuals who previously had melanoma have a higher risk recurrence; previously having had other primary skin cancers have also heightened the risk
  • A close family history of melanoma or other skin cancers – If an immediate family member has been diagnosed with melanoma, your risk is higher; this could be due to similar skin color, sun exposure habits or genetic mutations, although, the latter is rarer
  • A weakened immune system – Individuals with a weaker immune system are at higher risk of developing melanoma, the immune system can be compromised by certain diseases and drugs
  • Outdoor occupations make workers more vulnerable to skin cancer due to prolonged sun exposure, so protective measures are vitally important for this group.[24]

The risk can be multiplied if you have several of these risk factors, for example, if you have unusual moles and a family history of melanoma.

Skin Cancer Foundation – Melanoma causes and risk factors
Canadian Cancer Society – Risk factors for melanoma


[21] “Risk Factors for Melanoma.” Canadian Cancer Society. Canadian Cancer Society, 2015. Web. 02 June 2015.
[22] ibid.
[23] “Melanoma Causes and Risk Factors.” Skin Cancer Foundation. Skin Cancer Foundation, 2015. Web. 02 June 2015.
[24]Gawkrodger, D.J. (2004). Occupational Skin Cancers. Occupational Medicine, 54(7). doi: 10.1093/occmed/kqh098