Skin cancer in Australia: What you should know.

Some types of skin cancer can spread to other organs and be a threat to life. But the truth is that most skin cancers diagnosed in Australia do not have this potential. The terms used for the non-life threatening types can be confusing and and can cause unnecessary alarm.

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Knowledge of the different types of skin cancer and their various prognoses can give some perspective and  allay the fear that is often engendered with a diagnosis of "cancer". Such knowledge can also help you make a more informed decision about your treatment.

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Melanoma refers to cancer of the pigment-producing cells in the skin. The vast majority of skin cancers however are cancers of the keratin-producing cells and the majority of these are not life-threatening.

Even for melanomas, there are life-threatening types (those of an "invasive" type), and non-life threatening types. There are twice the number of non-invasive types compared to invasive types. Despite having zero potential to spread, the non-invasive types are still generally referred to as "melanoma", so this can be misleading.

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This section is provided for better understanding of the terms and to inform readers of treatment options that are appropriate for each type. There is also information on situations where non-surgical treatments are more suitable than surgery.

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What is a BCC?

BCC stands for Basal Cell Cancer. It is the commonest type of skin cancer. Although labelled as a cancer, BCCs do not spread to other organs. They can fester like rot and break down your skin but they won't kill you. "Cancer" is perhaps not the best word to aptly describe this type of growth; "basal cell proliferation" or "basal cell growth" are more appropriate terms. The vast majority of these growths can be easily diagnosed at our clinic without the need for biopsy. Small BCCs and thin BCCs can be easily removed without the need for cutting and stitching.

Bowen's Disease is a bad name because it's not really a disease. It is better referred to as "Squamous cell carcinoma in situ (SCC-in-situ) or "non-invasive SCC".

SCC-in-situ usually presents as a flat red scaly patch in a sun-exposed site but is common on the lower legs of older people too. It's a type of growth where skin cancer cells (and they are not melanoma cells!) are forming sheets in the uppermost layer of skin. The bottom line is that SCC-in-situ will not kill you. SCC-in-situ has a very low chance of transforming to a potentially dangerous "invasive SCC" (see below) and this is fairly obvious if it happens - a lump develops. 

The vast majority of SCCs-in-situ can be removed without the need for cutting and stitching. 

Invasive squamous cell cancer (SCC) of the skin is a very common type of skin cancer that is easily removed/cured in the vast majority of cases. Invasive means that cells have reached the 2nd layer of skin. Invasive SCC usually presents as a lump in a sun-exposed area with some scaliness at the top of the lump. These tumours are generally excised, but if detected when they are small (<1cm diameter), they can be more simply removed by scraping them off the skin and burning the base ("curettage and cautery"). There is a broad spectrum of types of SCC - the types that have potential to spread are larger and often lack scaling.

This is another lesion that sounds more threatening than it is. The bottom line is that melanomas-in-situ do not kill!

Some elaboration is given below to provide some context to this increasingly common diagnosis:

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Melanoma-in-situ (MIS) is the term used when a pathologist can identify abnormal cells (akin to melanoma cells) in a lesion but they are confined to the uppermost layer of skin.  It is regarded as a possible precursor to "invasive melanoma", and the emphasis should be on possible.  There is no need to panic with this diagnosis. It is best removed because of the undefined risk that it may change to an invasive melanoma if left. The pathologist cannot tell whether it was truly destined make tis change or not.  Intuitively, an MIS that is growing is probably more likely to convert to invasive melanoma than a MIS that is stable, but there is no data on this.

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The diagnosis of MIS has become more common over the last 30 years. There are 2 reasons for this: Firstly it is because because a lot more lesions are biopsied/excised, and the second reason is that the histological criteria for the diagnosis have changed. Some lesions diagnosed as MIS today would have been classified as a type of mole 20 years ago. Here is an article from the New England Journal of Medicine that highlights what has happened. The problems created by the escalation of melanoma diagnosis are outlined in this Australian paper: A Clinical Perspective of Melanoma Overdiagnosis.

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If MIS is diagnosed then it is best cut out with a clear margin. In Australia, the guidelines are that MIS be cut out with a 5mm margin from the visible edge of the lesion so that clear histological margins are achieved. But in the situation where clear histological margins have already been achieved on the biopsy, there is no evidence that another excision will reduce the risk of recurrence or further harms.  In addition, there are no guidelines as to what the minimum histologic margin should be.

Excision of MIS generally means a simple, straight-line cut, not a complicated one.

Some doctors may simply refer to melanoma-in-situ as being "melanoma" without further clarification. If you have been diagnosed with "melanoma" it might just be a MIS. It is best to ask. 

Do all skin cancers need to be cut out?

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Melanomas should be cut out (excised) but for thin basal cell cancers (BCCs) and some superficial types of squamous cell cancer (SCC) there are other treatments which are just as effective.  The ideal management for BCC is to remove the tumour in its entirety with little or no scarring and without infection. It makes no sense to be left permanently disfigured from a treatment when an equally effective treatment with little or no risk of disfigurement could have been used.

There are many situations where surgery is not the best option.  Non-surgical treatment options include curettage, photodynamic therapy, chemotherapy creams, or freezing (cryotherapy). Complete removal of thin BCCs following these treatments can  be verified using highly sensitive imaging technology known as optical coherence tomography (OCT). (Ref).

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The cosmetic benefit of a non-surgical treatment can be very significant. Of all treatments for BCC, it is photodynamic treatment (PDT) that has the least likelihood of scarring. Photodynamic treatment also has a mode of action that makes infection extremely unlikely.

We favour biphasic PDT as the treatment of choice for most superficial or thin BCCs in cosmetically sensitive sites. We will excise a BCC if that is your prefered treatment or when less-invasive treatment is not suitable.​​

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I've been diagnosed with a skin cancer. How do I know if a non-surgical treatment is suitable?

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Many BCCs and superficial squamous cell cancers (SCCs) are suitable for non-surgical treatment.

If the skin cancer is fairly flat then a topical treatment treatment may be all that is required. If it is raised but ≤ 1 cm diameter and clearly demarcated, then it can be removed by scraping it off and cauterising the base (curettage & cautery). 

Some clinics will not offer these treatments. Some will only discuss cutting and stitching. There are several reasons for this, but surgery is far from ideal when protocols dictate that the visible cancer should be cut out along with a 4-5 mm margin. This means for example, that if you have a superficial skin cancer on your face which is only 2 mm wide, you will potentially be left with a surgical defect which is over 1cm wide.  On sites like noses and foreheads, this means you will need a skin graft or other complicated repair, and this brings additional risks of infection and permanent disfigurement, as well as being costly.

​Our aim is to inform you of more-sophisticated, less-invasive options when they are appropriate. We can assess tumour margins and suitability for non-invasive removal with OCT imaging.

We can still excise a skin cancer if surgery is the best option, and this can be guided by the imaging so we don't cut any wider than needed. 

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Please phone us for advice.​​​​​​​​​​​

We perform laser sub-surface imaging (OCT) at our clinic. A scan takes less than 30 seconds and can verify removal of the cancer. Scanning can be done once the treatment wound has healed. It can be used following any non-invasive treatment or following curettage (see before and after scans of BCC removal in the image scroll here). OCT can also be performed following surgical removal. It is important to note that whilst "clear margins" following surgical removal is good news, it is no guarantee that the tumour has been completely removed.