Preventing melanoma: ultraviolet light, sunburn, tanning beds and what the evidence shows

This page is general information, not medical advice. Your own doctor or care team is the right source for questions about your skin, diagnosis or treatment.

Prevention research asks whether an exposure or a protective measure changes how often a disease occurs in a group. It does not explain why every individual develops melanoma, and it does not guarantee that melanoma cannot occur. The evidence about ultraviolet light, sunburn, tanning devices, and sunscreen has to be read with that distinction in mind.

Ultraviolet light and the skin

The World Health Organization's ultraviolet radiation fact sheet explains that ultraviolet radiation cannot be seen or felt. Sunlight is a source, and artificial sources include tanning devices. The organization describes ultraviolet radiation as carcinogenic to humans, meaning that it can cause cancer. It lists skin-cell DNA damage and sunburn among the immediate effects of exposure, and skin melanoma among its longer-term effects.

The fact sheet distinguishes immediate effects, such as sunburn, from longer-term effects, such as skin cancer. The World Health Organization also describes effects on the eyes and changes in skin over time. These are different outcomes of exposure; the presence or absence of a visible burn does not measure every effect of ultraviolet radiation.

The amount of ultraviolet radiation reaching the ground varies with the height of the sun, the time of year, altitude, cloud cover, and other environmental factors. The organization notes that levels can remain high under clouds. Water, sand, and fresh snow can reflect ultraviolet radiation. A day that feels cool, or a location that is not a beach, can still involve exposure.

Sunburn and differences in sensitivity

Sunburn is an immediate response to excessive ultraviolet exposure, rather than evidence that the skin is becoming healthier. The National Cancer Institute's prevention summary lists a history of blistering sunburns, especially during childhood or adolescence, among melanoma risk factors. It also lists long exposure to natural or artificial sunlight, many moles, and a personal or family history of melanoma.

Skin type can describe how readily someone's skin burns or tans. The institute describes greater melanoma risk in people with a fair complexion, including skin that freckles and burns easily or tans poorly. Those categories concern sensitivity and average risk. They are not a diagnosis and do not establish what a particular spot is.

The World Health Organization says that darker-skinned people also develop skin cancers and that eye protection matters for everyone. The National Cancer Institute likewise states that people of all skin colors can develop skin cancer. A discussion of differences in sensitivity therefore includes both the higher average risk associated with easily burned skin and the limits of treating any skin color as protection from all harm.

The institute distinguishes factors that can be changed from those that cannot, such as inherited characteristics. A family history, a past sunburn, and present exposure are different parts of that picture. This prevents a prevention discussion from becoming an explanation of why any particular person developed the disease. The research describes risk and protective factors across populations, with limits on what can be inferred for one person.

Indoor tanning and the research

Indoor tanning devices are sources of ultraviolet radiation. The National Cancer Institute includes artificial sunlight among melanoma risk factors, and the World Health Organization advises against artificial tanning. A tan is not a way of removing the risk associated with exposure. Agency guidance concerns the ultraviolet exposure itself, rather than whether it occurred outdoors or inside.

A systematic review and meta-analysis published in 2012 reported an association between sunbed use and increased melanoma risk. A systematic review gathers relevant studies; a meta-analysis combines their results. This review examined observational studies, which compared exposures and outcomes in groups of people rather than assigning people to use tanning devices.

The review reported that risk was higher with more sunbed sessions and with first use at a younger age. Its findings describe patterns across study populations. They do not identify which exposed person will develop melanoma, and they do not supply a timetable for an individual. The distinction between an association in research and a personal prediction remains important when reading risk information.

What an Australian sunscreen trial reported

A randomized trial follow-up published in 2011 reported fewer new primary melanomas in an Australian group assigned regular sunscreen use than in the group assigned discretionary use. The participants were adults in Queensland. Random assignment means that the researchers allocated the groups, rather than simply comparing people who chose different habits.

The follow-up examined melanoma after the sunscreen trial had ended. It reported a reduction in invasive melanomas, which are melanomas that have grown beyond the surface layer. The overall estimate was less certain, as reflected in the reported statistical interval. The paper's conclusion used cautious language about regular sunscreen use and melanoma prevention in adults.

This finding concerns the trial's groups, the way sunscreen was used in the study, and the period observed. It is not a guarantee for a person using sunscreen, and it is not a comparison of brands. It also answers a different question from a study of whether sunscreen reduces sunburn. A finding about a burn and a finding about cancer are not interchangeable.

Why the evidence summary stays cautious

The National Cancer Institute's prevention summary states that sunscreen has not been proven to protect against melanoma caused by ultraviolet radiation. It notes that other factors, including skin sensitivity and ordinary or atypical moles, can contribute to melanoma risk. The summary also describes studies in which counseling improved sun-protection habits without establishing whether skin cancers were reduced.

The trial report and the institute's summary can therefore be read as different kinds of evidence: a reported result from a particular study and a broader assessment of what prevention research has established. The institute's general point is that reducing risk does not ensure that cancer will never develop. The melanoma basics page explains the disease and the meaning of risk factors without making an individual forecast.

Protection as agencies describe it

The World Health Organization describes limiting midday exposure, seeking shade, covering skin with clothing, and using a broad-brimmed hat and ultraviolet-protective sunglasses. It places sunscreen on skin not covered by clothing and says it should not be used to extend time in the sun. The National Cancer Institute also describes clothing, hats, sunglasses, and limits on sun exposure as measures suggested by skin experts.

The sunscreen and clothing-label page explains what the different protection labels mean. The UV Index and outdoor days page explains how agencies describe sunlight conditions. For the research methods behind prevention and treatment studies, the clinical trials explanation describes the questions studies ask and the safeguards used.