1.2 Risk factors

1.2 Risk factors

The risk factors for developing keratinocyte cancer include the following.

Environmental and exogenous risk factors:

  • chronic sun exposure
  • multiple solar keratoses
  • solarium use
  • intensive UV exposure in childhood and adolescence – this is a stronger causative factor for developing BCC, whereas SCC is associated with chronic sun exposure over decades (Leiter & Garbe 2008); sun exposure in adulthood, however, is an important risk factor for both SCC and BCC (Iannacone et al. 2012).
  • past exposure to arsenic.

Personal risk factors:

  • some rare genetic conditions predisposing to skin cancer
  • skin types I and II (these have a higher risk of sunburn)
  • a history of blistering sunburn
  • increasing age
  • a previous diagnosis of melanoma or BCC/SCC (up to 60 per cent grow another within three years)
  • solar keratoses.

Lifestyle risk factors:

  • outdoor occupations
  • recreational sun exposure.

Medical risk factors

  • UVA and psoralen (PUVA) treatment for psoriasis
  • immunosuppression (e.g. post transplantation, chronic lymphomas and leukaemias)
  • previous radiotherapy
  • some photosensitising medications (e.g. methotrexate and voriconazole).