Skin cancer is the most common type of cancer in Australia. About 70% of Australians will have a skin cancer of some type during their lifetime. There are three basic kinds of cancer and within these three basic types there are varying degrees of severity. The three main kinds are basal cell carcinoma(BCC), squamous cell cancer(SCC) and melanoma. Of these, melanoma is potentially the most harmful with the greatest chance of spreading beyond the skin. Squamous cell cancer can also spread more widely but only in about 2% of cases. About 1 in 14 men will have a lifetime risk of getting a melanoma. The main aim of treatment is to detect and deal with skin cancers, especially melanoma, at an early stage. Someone with a superficial melanoma that is cut out (excised) will have greater than a 95% chance of long term survival. If the melanoma is deep and extensive this figure can reduce to below 50%.
So how do you know if you have a skin cancer? This is difficult. Each type of cancer has certain distinguishing features and close examination with appropriate equipment in experienced hands can give a fairly good idea what the lesion is. However despite this, for the average GP in Australia, we cut out 16 pigmented (brown coloured) lesions in order to find one melanoma and even for very experienced skin cancer doctors the figure is probably between 5 and 10, for each melanoma found. The first priority is to find and excise cancers, the second priority is to retain function of the skin, e.g. eye can still shut properly, and the third priority is cosmetics; how it looks.
Given how common skin cancers are in Queensland it is appropriate to have a regular yearly check of the skin. This can be from the age of 40 onwards but younger if there is a strong family history of skin cancer, a fair skin type, extensive sun exposure or worry over a particular lesion. New moles (naevi) do not commonly appear after the age of 40 so new pigmented lesions after this age merit a review. Something non pigmented that doesn’t heal by itself after 4 weeks also merits a closer look. When checking the skin we are looking for asymmetry of the lesion-A- (one half not matching the other), an irregular border-B-, inconsistent color-C-, large diameter-D- ( greater than 6mm) and for elevation-E-. ABCDE, easy to remember.
So you go to the doctor and he or she finds something suspicious. What do you do then? Well if it is a very superficial BCC, SCC or sun damaged skin ( solar keratosis) this can be treated by either cryotherapy ( freezing the lesion) or by the topical application of a cream for 3-4 weeks ( this often inflames the skin and it can look worse before it looks better). The doctor may want to take a sample of the lesion before doing this, a biopsy.
If the lesion is suspected to be a melanoma or a thicker SCC or BCC it is best excised and sent to the lab for analysis. Generally we want at least an initial 2mm margin of safety between the cancer and the cut edge to ensure complete clearance and if it is a melanoma this may be extended to between 5mm and 20mm depending on severity. So re-excisions to ensure these margins of safety is not uncommon. If it is a thick melanoma, greater than 1mm, you may be referred further to consider a biopsy of adjacent lymph nodes to ensure there is no spread already taken place.
Finally and most importantly though is good sun protection, and from an early age. It is hard with young kids to keep them constantly protected but it is a vital role in protecting against future cancers.
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