Is There Really Such Thing as a Healthy Tan?

Posted on Sep 18, 2013 by Michael Loftus

Skin cancer is maybe the most disconcerting of all forms of cancer given that its cause is something that we have generally assumed is good for us - sunlight. More specifically, it is overexposure to the ultraviolet (UV) light in sunlight that can damage the skin and too much of it can be dangerous whether it comes in ‘natural’ form or via routes such as tanning machines.

Skin cancer comes in two distinct forms;  non melanoma, which is in fact the most common form of any cancer and tends not to be registered in the official statistics, and the more life threatening malignant melanoma. Some 100,000 people are diagnosed each year in the UK with non-melanoma skin cancer however, cases of death from this form are typically uncommon.

Research inevitably concentrates more on malignant melanoma skin cancer and recent work has examined two particular anomalies; the fact that it is much more common in men than in women and that the genetic mutation that is closely associated with it is also connected to obesity.

The cause and processes that lead to melanoma are fairly well understood by now. Ultraviolet radiation causes damage to cells in the basal layer of the skin that produce the pigment that causes skin colour. The basal cell layer is continually producing new cells which are pushed through the other layers of the skin and finally shed at the surface. The fact that this cell layer is the site of rapid cell division and reproduction possibly means that the risk of mutation and hence cancer is greater in any event – the ‘disruptive presence of UV radiation adds a further dimension to this risk’.

The resulting melanomas resemble moles – sometime they actually develop from moles.

In the UK, some 13,000 people each year are diagnosed with melanoma skin cancer ( the figure is about 130,000 in the United States). Annual mortality rates from the condition in the UK are about 2,200 ( US – 9,000). Exposure to UV radiation is a principal cause – excess exposure can cause patches of hard, dry discoloured skin called solar keratosis. This condition itself significantly raises the risk of melanoma developing.

Other risk factors include the presence of moles on the skin which may suggest a genetic problem with the basal cell layer. People with a higher number of moles, or large, abnormally shaped moles are at a higher risk of melanoma  and should be particularly careful about their own exposure to ultra violet radiation.

There are a range of other factors connecting skin type and exposure to ultraviolet light that also increase the risk of  melanoma developing. These include freckles on the skin, and being fair or red haired and being prone to sunburn in general. Those fair skinned people who tend to sunburn and peel – rather than tan -  are also susceptible. People of European heritage living now in locations with a lot of sun such as Australia are more at risk.

Paradoxically, the use of sun block has in some research been seen to lead to higher incidence of melanoma but it is suspected that this may be due to an expectation that sun block provides more protection than is the case and as a result,  individuals end up spending even more time in the sun and therefore increase their risk.

The common desire for people to expose themselves to the sun’s rays in the hope of a ‘healthy’ tan is a major contributor to the fact that in Great Britain, malignant melanoma incidence rates have seen the most  rapid increase of the most common cancers for both sexes over the last three decades.

As with so many other cancers, the first course of action is to avoid the circumstances that are likely to give rise to it and managing one's exposure to ultraviolet light is the key. The second issue is to be aware of any new moles as they appear and to seek advice on their cause – early detection and treatment is always key to any cancer survival.

The latest research into this type of cancer has suggested some significant features related to the condition. A research team based in Leeds investigated the tumours of 13,000 malignant melanoma patients and 60,000 unaffected individuals. This revealed that people with specific particular variations in a chain of DNA within the FTO gene (a gene commonly associated with obesity) could be at greater risk of developing melanoma. The researchers concluded that these early findings could potentially lead to development of drugs to treat melanoma.

Research has also highlighted the fact that far more men than women die from skin cancer and even though similar numbers of both sexes are diagnosed, 60% of  deaths resultuing from the condition are men. One cause behind this may be due to the fact that men typically delay seeking help, but biology may also play a part and German research has noted a gene that seems to make men more susceptible to melanoma.

So although the fundamental causes of melanoma are well understood, developing further understanding and treatment  will undoubtedly continue to be a focus of medical effort.