Causes of skin cancer
This page contains information about the links between sun exposure, sunbeds and cancer. It will also tell you about who is most at risk. Click on the links below to read about specific topics.
On this page
- Too much sun exposure causes skin cancer
- Sun exposure in childhood affects your skin cancer risk as an adult
- Some people have higher risks of melanoma and need to take extra care
- Tanning is not a sign of health and offers little protection against burning
- Sunbeds are not safe and can also increase the risk of skin cancer
International health organisations agree that sun exposure is the main cause of skin cancers 1. Ultraviolet (UV) radiation from the sun damages DNA, which leads to the development of cancer 2.
Research has found that over eight in ten malignant melanomas are linked to excessive exposure to sunlight and use of sunbeds 3.
People who receive the highest exposures to the sun have about 20-35% higher risks of melanoma 4, 5. but sunburn increases the risk of this disease even more. Two analyses of several studies showed that sunburn at any age nearly doubles the risk of malignant melanomas.
Recent studies have shown that intense, intermittent sun exposures, such as holiday sunbathing, pose the greatest risk of malignant melanomas 4, 5. The recent increase in the numbers of people holidaying abroad may contribute to the rising numbers of melanoma cases 4, 6, 7.
Experts agree that a person’s lifetime skin cancer risk is strongly affected by sun exposure during the first 15 years of life 8, 9. Studies indicate that sunburn during childhood can double a person’s risk of skin cancer 4, 5. And migration studies have found that people who move to areas with higher UV exposures (like Australia) have higher melanoma risks if they arrive as children than as adults 10, 11.
Some studies have found that sun protective behaviours during childhood can lead to fewer moles, a known risk factor for melanoma 12-15. For example, one study showed that regular sunscreen use during the first 18 years of life can reduce the risk of NMSC by 78% 16, 17
It is especially important to teach children sensible sun behaviours in the first few years of life when they are more likely to develop unhealthy attitudes to sun exposure 18-22.
Studies have shown that some people have a higher risk of melanoma than others. You should take extra care in the sun if you:
- have fair skin 23
- have red or blond hair 23
- have blue, green or hazel eyes 23
- have freckles 23
- tan poorly and burn easily 19, 20
- have large numbers of moles 24, 25
- have a family history of skin cancer; up to one in ten melanomas occur in people with inherited predispositions 23, 26
Ethnic minorities with darker skins are up to 20 times less likely to develop melanoma than white Caucasians 27, 28. They have higher levels of the pigment melanin, which provides some protection from UV-induced damage 21. But people with darker skin can still burn and develop skin cancers, especially on non-pigmented parts of the body like the soles of the feet, or the nail bed 29.
Far from being a sign of health, science tells us that a tan is a reaction to DNA damage in the skin. It is a sign that your body is trying to repair damage that has already happened 30, 31. And pre-holiday tans or sunbed tans offer very little protection against the sun. Some studies have found that tans only offer protection equivalent to using factor 3 sunscreen 32, 33.
Studies have linked sunbed use to both malignant melanoma and NMSCs 1, 34. A comprehensive review published in 2012 of studies on sunbeds and cancer concluded that people who use sunbeds for the first time before the age of 35 have a 59% higher risk of melanoma than never users. 35 Another study estimated that sunbeds cause 100 deaths from melanomas every year in the UK 36. Sunbeds also cause eye damage and premature skin ageing 37.
IARC also concluded that sunbeds provide no positive health benefits. They do not protect against further damage from the sun and they do not help your skin to make enough vitamin D. 35
Sunbeds are marketed as a ‘controlled’ way of getting a ‘safer’ tan 38. But actually, sunbeds are no safer than exposure to the sun itself 39. It is a common misconception that sunbeds emit only UV-A radiation, and not UV-B, the type which causes most sunburns. But all sunbeds emit some measure of UVB, and even this tiny proportion is enough to cause substantial damage to our skin 40.
UVA can also damage the skin and the levels of UV-A from sunbeds can be over 10 times higher than that of the midday sun 39. Studies have shown that up to half of all sunbed users suffer from sunburns 41. And in people who are prone to burning, UV-A from sunbeds can burn the skin faster than the sun 42.
- IARC, Solar and ultraviolet radioation. Monographs on the evalutation of carcinogenic risks to humans. 1992, Lyon: IARCPress. Link
- Gilchrest, B., et al., The pathogenesis of melanoma induced by ultraviolet radiation. N Engl J Med, 1999. 340: p. 1341-8. PubMed
- Parkin, M. et al., The fraction of cancer attributable to lifestyle and environmental factors in the UK in 2010. BJC 2011. 105 Supp 2 6 December 2011.
- Elwood, J. and J. Jopson, Melanoma and sun exposure: an overview of published studies. Int J Cancer, 1997. 73: p. 198-203. PubMed
- Gandini, S., et al., Meta-analysis of risk factors for cutaneous melanoma: II. Sun exposure. Eur J Cancer, 2005. 41(1): p. 45-60. PubMed
- Nelemans, P., et al., Effect of intermittent exposure to sunlight on melanoma risk among indoor workers and sun-sensitive individuals. Environ Health Perspect, 1993. 101: p. 252-5. PubMed
- Elwood, J., Melanoma and sun exposure: contrasts between intermittent and chronic exposure. World J Surg, 1992. 16: p. 157-65. PubMed
- Whiteman, D., C. Whiteman, and A. Green, Childhood sun exposure as a risk factor for melanoma: a systematic review of epidemiologic studies. Cancer Causes Control, 2001. 12: p. 69-82. PubMed
- Autier, P. and J. Dore, Influence of sun exposures during childhood and during adulthood on melanoma risk. EPIMEL and EORTC Melanoma Cooperative Group. European Organisation for Research and Treatment of Cancer. Int J Cancer, 1998. 77: p. 533-7. PubMed
- Khlat, M., et al., Mortality from melanoma in migrants to Australia: variation by age at arrival and duration of stay. Am J Epidemiol, 1992. 135(10): p. 1103-13. PubMed
- Mack, T. and B. Floderus, Malignant melanoma risk by nativity, place of residence at diagnosis, and age at migration. Cancer Causes Control, 1991. 2: p. 401-11. PubMed
- Gallagher, R., et al., Broad-spectrum sunscreen use and the development of new nevi in white children: A randomized controlled trial. JAMA, 2000. 283: p. 2955-60. PubMed
- Haydon, A.M., et al., The effect of physical activity and body size on survival after diagnosis with colorectal cancer. Gut, 2005. PubMed
- Autier, P., et al., Sunscreen use, wearing clothes, and number of nevi in 6- to 7-year-old European children. European Organization for Research and Treatment of Cancer Melanoma Cooperative Group. J Natl Cancer Inst, 1998. 90: p. 1873-80. PubMed
- English, D.R., E. Milne, and J.A. Simpson, Sun protection and the development of melanocytic nevi in children. Cancer Epidemiol Biomarkers Prev, 2005. 14(12): p. 2873-6. PubMed
- Severi, G., et al., Sun exposure and sun protection in young European children: an EORTC multicentric study. Eur J Cancer, 2002. 38: p. 820-6. PubMed
- Jarrett, P., C. Sharp, and J. McLelland, Protection of children by their mothers against sunburn. BMJ, 1993. 306: p. 1448. PubMed
- Holly, E., et al., Number of melanocytic nevi as a major risk factor for malignant melanoma. J Am Acad Dermatol, 1987. 17: p. 459-68. PubMed
- Gallagher, R., et al., Sunlight exposure, pigmentation factors, and risk of nonmelanocytic skin cancer. II. Squamous cell carcinoma. Arch Dermatol, 1995. 131: p. 164-9. PubMed
- Rhodes, A., et al., Risk factors for cutaneous melanoma. A practical method of recognizing predisposed individuals. JAMA, 1987. 258: p. 3146-54. PubMed
- Saraiya, M., et al., Interventions to prevent skin cancer by reducing exposure to ultraviolet radiation: a systematic review. Am J Prev Med, 2004. 27: p. 422-66. PubMed
- Marrett, L., et al., Use of host factors to identify people at high risk for cutaneous malignant melanoma. CMAJ, 1992. 147: p. 445-53. PubMed
- Gandini, S., et al., Meta-analysis of risk factors for cutaneous melanoma: III. Family history, actinic damage and phenotypic factors. Eur J Cancer, 2005. 41(14): p. 2040-59. PubMed
- Tucker, M.A. and A.M. Goldstein, Melanoma etiology: where are we? Oncogene, 2003. 22(20): p. 3042-52. PubMed
- Gandini, S., et al., Meta-analysis of risk factors for cutaneous melanoma: I. Common and atypical naevi. Eur J Cancer, 2005. 41(1): p. 28-44. PubMed
- Ford, D., et al., Risk of cutaneous melanoma associated with a family history of the disease. The International Melanoma Analysis Group (IMAGE). Int J Cancer, 1995. 62(4): p. 377-81. PubMed
- NCI, SEER Cancer Statistics Review, 1998-2002. Link
- Scotto, J., T. Fears, and J.J. Fraumeni, Incidence of nonmelanoma skin cancer in the United States. 1983, Bethseda, MD.: National Cancer Institute, National Institutes of Health.
- Crombie, I.K., Racial differences in melanoma incidence. Br J Cancer, 1979. 40(2): p. 185-93. PubMed
- Pedeux, R., et al., Thymidine dinucleotides induce S phase cell cycle arrest in addition to increased melanogenesis in human melanocytes. J Invest Dermatol, 1998. 111: p. 472-7. PubMed
- Eller, M., et al., Enhancement of DNA repair in human skin cells by thymidine dinucleotides: evidence for a p53-mediated mammalian SOS response. Proc Natl Acad Sci U S A, 1997. 94: p. 12627-32. PubMed
- Gange, R., et al., Comparative protection efficiency of UVA- and UVB-induced tans against erythema and formation of endonuclease-sensitive sites in DNA by UVB in human skin. J Invest Dermatol, 1985. 85: p. 362-4. PubMed
- Bykov, V., J. Marcusson, and K. Hemminki, Protective effects of tanning on cutaneous DNA damage in situ. Dermatology, 2001. 202: p. 22-6. PubMed
- Lazovich, D. and J. Forster, Indoor tanning by adolescents: prevalence, practices and policies. Eur J Cancer, 2005. 41: p. 20-27. PubMed
- Boniol M, Autier P, Boyle P, Gandini S. Cutaneous melanoma attributable to sunbed use: systematic review and meta-analysis. BMJ 2012. 345:e4757. PubMed
- Diffey, B., A quantitative estimate of melanoma mortality from ultraviolet A sunbed use in the U.K. Br J Dermatol, 2003. 149: p. 578-81. PubMed
- Wester, U., et al., Population UV-dose and skin area--do sunbeds rival the sun? Health Phys, 1999. 77: p. 436-40. PubMed
- Gies, H., C. Roy, and G. Elliott, Artificial suntanning: spectral irradiance and hazard evaluation of ultraviolet sources. Health Phys, 1986. 50: p. 691-703. PubMed
- Gerber, B., et al., Ultraviolet emission spectra of sunbeds. Photochem Photobiol, 2002. 76: p. 664-8. PubMed
- Wright, A., et al., Survey of the variation in ultraviolet outputs from ultraviolet A sunbeds in Bradford. Photodermatol Photoimmunol Photomed, 1996. 12: p. 12-6. PubMed
- Autier, P., Perspectives in melanoma prevention: the case of sunbeds. Eur J Cancer, 2004. 40: p. 2367-2376. PubMed
- Swerdlow, A. and M. Weinstock, Do tanning lamps cause melanoma? An epidemiologic assessment. J Am Acad Dermatol, 1998. 38: p. 89-98. PubMed