There is no single cause of melanoma…
No one really knows the exact cause of melanoma and there are numerous theories as to why certain people get this skin cancer and others do not. The sun is a clear suspect in developing malignant melanoma and early exposure to the effects of severe sunburn is just one of the reasons why many researchers believe melanoma can develop later in life.
My research has led me to believe there are currently 6 documented causes of melanoma…
- Ultraviolet Radiation – Aparantly the most common cause of melanoma. Over exposure to UVR damages skin cells and causes them to mutate or alter and form a tumor. There are two types of radiation from sunlight – UVA and UVB. UVA does not cause sunburn as such, but does the most damage to skin. It penetrates deepy into the skin layers, damaging the collagen and elastin that keeps skin taut and supple. It is directly responsible for skin aging and premature wrinkling and is now believed to be an initiator to skin cancer. UVB only penetrates the outer layer of the skin but has the ability to cause severe sunburn. In young children, such exposure to the sun significantly increases the risk of malignant melanoma later in life.
- Dysplastic Nevus – A dysplastic nevus is a mole that is currently non cancerous yet has the characteristics of a melanoma. It will be larger in size, may have an uneven border and may be raised or multi-pigmented. Alternatively known as an atypical nevus (meaning ‘not normal’), these types of moles mainly appear to be hereditary and put the patient at a much higher risk of developing melanoma, especially if there are many of them on the body. People exhibiting over 100 atypical moles are said to be suffering from Atypical Mole Syndrome, which puts them at even further risk of one of them becoming malignant. This is an important cause of melanoma and one that many people are unaware of.
- Heredity – Is skin cancer hereditary? It isn’t as such, however, it is your genetically inherited skin type that may determine if you are at higher risk of developing a melanoma. If you are fair skinned and have skin which burns easily, of Anglo/Irish decent and have freckles and light eyes, you are at higher risk of developing skin cancer in general. If you have previously had a melanoma, you have a higher chance of developing another and if a close relative has suffered it, you should make sure you have your skin checked for changes as you will also be at risk.
- Tanning Beds – The International Agency for Research on Cancer (IARC) now confirms that any form of UV tanning is definetely carcinogenic to humans and believes it is as serious as cigarette smoke or asbestos. Radiation from artificial tanning sources (tanning beds) emitts mainly UVA rays which penetrate deeply into the skin layers. This damages the skin cells causing them to change abnormally which risks a tumor growing. High powered tubes in tanning beds transmit radiation that is far more intense than that of ordinary sunlight. Just one session as an adolescent can increase the risk of developing skin cancer later on by 75% according to the International Agency for Research in Cancer or IARC. If a young adult has many moles on their body (atypical mole syndrome), there is a huge risk of the cells inside these moles becoming damaged from such high powered, interittent bursts of radiation.
- Thermal Burn Scars** – Contrary to what some institutions may state, there is a rare chance that a melanoma may develop on a burn scar or from a long-term ulcer. Although more often the skin cancer acquired is squamous cell carcinoma, a small minority of burn scars can develop a melanoma. There is little documentation available for me to thoroughly research this subject, but it is of particular interest as it is how my mother developed a melanoma on her forearm. Her small scar from an oven burn became pigmented (and small freckles appeared around the site), raised and ulcerated. When it was removed, it was diagosed as malignant and had a thickness of 2.2mm. I am presuming a skin cancer can grow from a scar site due to damage to the skin cells that mutate (abnormally alter) and become a tumor, rather than repair. I will seek more information on this subject and add any insight when discovered.
- Immune Suppression – Individuals who have undergone organ transplant and are receiving anti-rejection medication are at higher risk of developing skin cancer. Again, the skin cancer they may acquire is normally squamous or basal cell carcinoma, but occasionally it can result in a malignant melanoma forming anywhere on the body. It is due to the immune system being unable to defend and rebuild damaged cells which then go on to develop into a skin tumor. However, it does mean that the body will not reject the new organ. In HIV/AIDS patients, there is a 30% increase in risk of developing melanoma according to AIDS, (AIDS 23: 385-393, 2008) resulting again, from immune suppression.
To summarise, although it is greatly important to reduce the amount of ultraviolet exposure we receive from leaving skin exposed to sunlight, there are also other points to consider when trying to prevent the cause of melanoma. Most importantly, in my opinion, is the importance of avoiding the use of tanning beds completely, keep children up to the age of 18 out of direct sunlight as much as possible (this can reduce the risk of melanoma by up to 78%!), and check your skin regularly for changes especially if you have more than 50 or so moles.