Skin checks save lives.
Common Types of Skin Cancer
Melanoma
What is a melanoma?
Melanoma is a type of cancer of the skin.
It is derived from melanocytes, melanocytes are cells which produce pigment and transfer this pigment to basal keratinocytes. The pigment functions to protect cells from harmful radiation produced by the sun.
Melanomas occur when melanocytes cells multiply excessively and grow in an atypical or disorganized pattern.
While melanoma is more commonly seen in sun exposed areas it can occur anywhere on the body including in the backs of the eyes or the mouth.
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What increases my risk of developing melanoma?
There are multiple factors that increase a person's risk of developing melanoma. These include:
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Family history of melanoma.
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Fair skin
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Large number of benign naevi (moles)
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Naevi with atypical architecture (previously know as dysplastic naevi).
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Sun exposure
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High sun screen use: due to increased incidental exposure.
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Welding
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Smoking
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Should I have all of my moles removed to decrease my risk of developing melanoma?
No, sometimes normal looking moles may end up being a melanoma, but a melanoma is just as likely to occur in normal skin as it is in a pre-existing mole (naevi).
Congenital naevi (birth mark) carry a slightly increased risk of developing skin cancer, however, the ones that have a significantly increased risk are usually too large to remove without significant disfiguration. If a congenital naevi is quite dark laser may be used to lighten them but should not be used to the point of completely removing the pigment.
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Will laser mole removal decrease my chances of developing melanoma?
No, laser pigment removal will remove the pigment but not the cells that produce the pigment.
Laser can produce quite atypical appearances within moles, sometimes the pigment may appear quite dark compared to previously and the appearance has been occasionally mistaken for a melanoma.
In theory laser mole removal will actually increase the risk of developing a more advanced melanoma as the visual changes doctors usually used to diagnose a melanoma may be absent in the early stages of the development of the cancer due to the lack of pigment. If you decided to go ahead with laser removal of your moles make sure the size and locations of these moles are well documented prior to undertaking this procedure.
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How is melanoma diagnosed?
Melanoma is diagnosed by a pathologist. An experienced skin doctor can advise you of the risk of melanoma from its appearance but for a formal diagnosis the entire lesion must be removed.
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I've had an atypical/dysplastic naevi cut out, why is the doctor recommending that I have a further procedure to cut it out?
Atypical/dysplastic naevi are naevi which have some signs of abnormal growth, they are below the threshold for melanoma, however, the diagnosis of melanoma is an art not a science one pathologist may look at a slide and call the lesion a high grade atypical naevi, the next may look at the side and call it a melanoma. Many skin doctors choose to treat high grade atypical naevi as a melanoma because only part of the lesion is examined by a pathologist and there is a risk of melanoma being missed. Treating a high-grade naevi the same as a melanoma decreases the chances of a missed melanoma progressing to an invasive melanoma.
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Why do you just take a small margin around the spot and then come back and do a bigger excision? Wouldn't it be better to take the entire thing out the first time?
We generally take the entire lesion to ensure that we get an accurate diagnosis. A small margin means that if the lesion is not a melanoma then you will only have a small scar. It also means if the melanoma is advanced beyond the superficial layers of the skin the sentinel lymph node studies that will be recommended are more likely to be accurate. The sentinel lymph node studies are needed to have access to the drugs used for melanoma.
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How often should I have skin checks after being diagnosed with a melanoma?
Funny thing about skin cancers, its very common for them to bring friends and these friends can be anywhere on the body.
The general recommendation is skin checks every 3 months for the first 2-3 years and then every six months until the 5 year mark.
After 5 years you should have ongoing yearly skin checks for the rest of your life.
Men should also have regular screening for prostate cancer, as a diagnosis of melanoma increase the risk of developing prostate cancer.
Can melanoma be treated topically?
At this point in time there are no topical treatments recommended by the TGA for melanoma.
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What can I do to decrease my risk of developing melanoma?
Using sunscreen and taking other protective measures is currently the only way to decrease your risk.
Squamous cell Cancer (SCC), Intraepithelial Carcinoma (IEC), Bowen's disease, Actinic Keratosis, Solar Keratosis and Sun Spots
What do all of these skin cancers have in common?
All of these cancers are due to the same underlying cause, they are just at different points in the disease process.
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​Sun spots/solar keratosis/actinic keratosis​
Caused by chronic exposure to UV rays. The present as small red spots mostly in sun exposed areas and may have overlying crusting of the skin.
It is due to abnormalities of the keratoncytes, which are the predominant cell type in the skin. There is also an associated chronic inflammation and there may be increased pigmentation of the keratoncytes.
Approximately 20% of people with these lesions will develop a squamous cell cancer either in one of these lesions or elsewhere on the body. They are considered to be benign but with the potential to develop into a skin cancer. The cancers that develop in these lesions rarely spread elsewhere in the body.
Solar chelitis is a variant of this disease process which occurs on the lips. In contrast to the rest of the skin these lesions tend to develop fast and they tend to spread early elsewhere.
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Bowen's disease/Intraepithelial Carcinoma
Slowly enlarging red patch with crusting or scaling.
The skin cells are abnormal, but there is no extension beyond the basal layer of the skin. The skin often has the look and feel of velcro.
Somewhere between 5-11% of these cancers will progress to squamous cell cancer.
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Squamous cell cancer
Abnormal skin cells with penetration of the disease process beyond the basement membrane.
Most commonly it occurs as a progression of the disease process above, but can also occur in inflamed skin, scar tissue from burns and stasis ulcers.
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In essence this is a field disease rather than a single spot. There is underlying generalized sun damage which will have areas of progression over time.
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If only a small percentage of sun spots progress to invasive skin cancers why do you treat the sun spots?
Invasive squamous cell cancers (SCCs) only arise in abnormal skin, we have non invasive ways of treating precancerous sun damage which can result in minimal or no scarring. Of course another option is to regularly monitor sun spots to prevent progression to more invasive cancers. Its also not always possible to decide exactly when a skin lesion has progressed from benign to cancerous.
Once I've had an SCC how often should I be getting skin checks?
Its variable but if you have recently had an aggressive SCC or you have a lot of sun spots or Bowens disease you will often be seen every 6 months to start with, usually with a view to clearing up the other abnormal skin which is has a higher risk of progressing to invasive cancer.
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If I've had one is there anything I can do to prevent another?
Yes. basic sun protection such as sun screen, hats, long sleeved shirts and sunglasses.
There are also various topical therapies which can either directly remove or trigger the immune system to take care of sun damaged cells.
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I just see my regular GP every 3-6 months and have all of my sun spots frozen, why are you recommending a different treatment?
Cryotherapy is imprecise, it can work for smaller lesions, but it may just slow down the disease progression in other cases. If you have had a lesion that has been frozen more than once it is generally a good idea to have a biopsy to ensure that there isn't an underlying invasive skin cancer. Also cryotherapy works just as well on benign skin lesions.
In people with olive or darker skin cryotherapy will also cause hyper or hypo pigmentation.
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I've previously just treated my face with Effudex every few years why do you want me to have a biopsy of a spot on my face?
Effudix will treat Sun spots and Bowen's disease, it won't treat invasive SCC. Unfortunately when effidix is used to treat invasive SCC the overlying skin can grow back looking normal and the cancer can continue to grow under the surface.
Basal Cell Cancer (BCC)
What is a Basal Cell Cancer?
Basal cell cancers (BCCs) are a cancer that arises from the cells that form the hair follicle, although the exact cell type is unknown. They tend to be very slow growing and generally invade locally rather than spreading distally. They occur more frequently on sun damaged skin.
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Do they run in families?
There are several know genes that increase the risk of people developing BCCs. These people will often start developing multiple BCCs in their 20s but some syndromes will even result in their development at or prior to birth.
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I've had a BCC, how often do I need to get a skin check?
Yearly to start with.
BCCs are unusual in that their appearance will often be quite variable especially if they are superficial, what may be prominent one day will be almost invisible a week later.
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Can BCCs be treated topically?
Yes, however, a biopsy is usually recommended prior to treatment as there are several different varieties of BCC's and topical therapy is more successful with some varieties compared to others. Effudix shouldn't be used to treat BCCs.