Sun spots, moles and skin cancer
A sunspot or ‘actinic keratosis’ has a scaly, pinkish
appearance on sun-exposed skin. Sunspots are extremely common among
fair-skinned people living in Australia. When sun spots develop, this
indicates that the skin has been damaged by the sun and there is an
increased risk of skin cancers developing. If left untreated, sun
spots may progress to squamous cell carcinomas (SCCs),
which are cancerous. This is why sun spots are usually treated upon
detection. Cryotherapy (freezing) is the standard treatment but there
are other treatments available.
A mole is a pigmented spot that appears on the skin during childhood,
which develops from melanocyte cells. Most adults have around 20 pigment
spots somewhere on their body which develop over the years, usually
peaking in adolescence. The number of moles a person has depends upon
their family history, sun exposure and other factors such as pregnancy.
Most moles are harmless. However, sometimes moles can change into
a potentially fatal form of skin cancer known as melanoma.
If melanoma is detected early, it may be effectively treated. So whenever
you notice a change in a mole or find anything suspicious, see your
doctor as soon as possible. Harmless moles are usually small (less
than 5mm in diameter) with well defined edges. They may be flat or
raised and are usually evenly coloured with no more than one or two
shades of brown. They may also be what is known as ‘dysplastic’ –
larger with ill-defined edges and irregular colouring. The majority
of melanomas arise from normal skin and not from a pre-existing mole.
The removal of normal moles to prevent the development of melanoma
is strongly discouraged as it does not reduce the risk of melanoma.
Melanoma can arise from any melanocyte in the body including in the
eye, gall bladder and mucosal surfaces.
Moles and freckles that may prove problematic include those that:
- Increase in size
- change colour (melanomas often develop a blue or black
- change shape
- have an irregular border
- become itchy
- have recently appeared on normal-looking skin.
These changes are normally noticed over several weeks or
months, rather than days.
It is advisable to perform a do-it-yourself skin check every three
months by following six easy steps:
If you find a mole, freckle or spot that looks suspicious, see
your doctor as soon as possible.
- Strip off and have a mirror handy
- Check your chest, stomach and the front of your arms and legs
- Check the back of your arms and legs including soles of feet
- Twist to see your sides
- Check your face, ears and back with the mirror
- Ask someone to check your back, or examine your back with a hand-held
mirror while facing a wall mirror.
Australia has the highest rate of skin cancer in the world. According to The Cancer Council, two out of three people who
spend their childhood and teenage years in Australia will develop
some form of skin cancer later in life [unprotected sun exposure
during the first 15 years of life more than doubles your chance of
developing skin cancer]. Given that the majority of us have migrated
from Northern European territories, we’re essentially a pale-skinned
population living in a dark-skinned people’s land.
The fact is, anyone who spends time in the sun can develop skin cancer. Some people have a higher risk than others. Your skin type, the colour
of your eyes, the number of times that you have experienced sunburn,
any history of previous skin cancers, your location on the planet
(latitude and longitude) can all play a contributing role.
What’s important is to be aware of the warning signs of skin cancer
because early detection may be crucial to survival.
Are you at risk?
You should be particularly careful about checking your skin if you
have any of the following:
- A large number of moles
- Suffered from sunburn in the past
- Fair skin that burns easily, freckles and doesn’t tan
- Blue or green eyes and/or fair or red hair
- Been diagnosed with skin cancer in the past
- A family history of melanoma.
Fortunately, most skin cancers can be completely cured if
Skin cancer is caused by the build-up of ultraviolet radiation (UVR)
in the cells of the skin, which may eventually cause a tumour to develop.
The skin’s immune system is an important defence mechanism in preventing
potentially cancerous cells from developing into tumours. When the
immune system is weakened, more cancers will develop.
The three most common skin cancers in Australia which are named after
the type of skin cell from which they arise include basal
cell carcinoma (BCC), squamous cell carcinoma (SCC) and melanoma (cancerous mole).
Basal cell carcinoma (BCC)
The most common type of non-melanoma skin cancer in Australia is the
basal cell carcinoma. BCCs account for approximately 80% of all skin
cancers. BCCs are most commonly located on the ears, nose and other
exposed parts of the body (the face and neck). Normally they do not
spread beyond the skin, but when they are neglected, can penetrate
the skin quite deeply, producing a destructive ulcer. This is why
they are usually removed. This may be by a minor surgical procedure
performed under anaesthetic by a GP, dermatologist or surgeon. After
assessment by a dermatologist, some BCCs can be removed by curettage
and cautery (sharp scraping and burning), cryotherapy (freezing with
liquid nitrogen) or some new medicated creams in select cases.
Squamous cell carcinoma (SCC)
Squamous cell carcinomas (SCCs) are very common in Australia but potentially
much more dangerous than BCCs if left untreated, because they can
spread to other parts of the body. SCCs arise from the outer layers
of the skin. They have a red, scaly sore appearance that may itch,
weep and never seems to heal. They appear in areas most commonly exposed
to the sun – the head, neck, upper back and the arms and legs.
SCCs may develop from pre-existing “sun spots” (actinic keratoses)
which are not yet cancerous. While these sun spots can be treated
with liquid nitrogen cryotherapy, SCCs, except in very special circumstances,
should not be treated with this technique, as the freezing does not
penetrate deeply enough to kill the tumour cells, allowing the cancer
to recur, often much more aggressively and extensively (deeper into
As they grow, SCCs can spread to the lymph nodes (under the armpits,
in the groin and neck) or via the bloodstream to other organs. This
creates a dangerous situation where the cancer is much harder to treat
or cure by simple removal.
For this reason, SCCs must be removed when detected. This is usually
done with surgery (by a GP, dermatologist or surgeon) under local
anaesthetic. Radiotherapy, which uses X-rays to kill the cancer cells,
is an alternative in selected patients following assessment by a dermatologist.
If the SCC is found to have spread to the lymph nodes these may also
need to be removed, or if small enough, can be removed completely
with regular surgical excision resulting in cure.
Melanoma (cancerous mole) is the fifth most common (but curable) cancer
in Australia and the most common cancer affecting men and women aged
15 to 44 years. It is also the most dangerous form of skin cancer
and in one-third of cases may arise from a pre-existing mole. [The
risk of developing melanoma is 1 in 25 for males and 1 in 38 for females].
Since it is known to run in families, genes are thought to play a
role in developing the disease.
A melanoma arises from the pigment forming cells in the skin and can
spread throughout the body if undetected and untreated. A melanoma
can occur anywhere in the body, not just on those areas that are exposed
to the sun. Sometimes it can arise on the sole of the foot, the palm
of the hand or under the nails. It is usually dark and can grow quickly
and spread to nearby lymph nodes, or via the bloodstream to distant
organs like the bones, liver, lungs or brain. On occasions, melanoma
may be flesh-coloured, making early detection hard. Furthermore, many
dark spots can be confused with melanomas, while other melanomas may
appear to the untrained eye to be quite harmless.
Most melanomas are linked to too much sun exposure and the number
of moles you have. They can be effectively treated if diagnosed early
enough. To allow for early detection of melanoma, anyone with a family
history of the disease and anyone who has multiple moles should be
examined regularly by an appropriately trained and experienced doctor
(such as a dermatologist).
Sun protection and regular skin checks, particularly if you have fair
skin, are the best form of protection against melanoma.
What to look for
Although the skin on our bodies is always changing, most harmless
or benign moles do not change over a short period of time. Key features
of malignant moles include:
- Changes in size
- Changes in shape
- Changes in colour or pattern
- Bleeding or itching.
Any of these features are cause for concern and should be checked
promptly by your dermatologist.
At Eastern Suburbs Dermatology we use the world-leading, locally developed SolarScan monitoring system – an advanced skin imaging system approved by the
Melanoma Foundation – to help in the analysis and detection of even
minute changes in a mole.
Preventing skin cancer
Take the following measures to minimize your chance of developing
- Avoid the sun in the middle of the day (10am to 4pm) as much as
- Stay in the shade whenever possible
- Wear protective clothing (preferably closely woven fabrics that
aren’t transparent when held up to the light or those with
UV ratings on the labels) that covers the arms, legs and neck
- Don a broad-brimmed hat and wrap-around sunglasses that block
out 95-100% of UV rays
- Apply SPF30+ broad-spectrum sunscreen to the skin. Apply it 20
minutes or so before going outside and reapply every two hours while
in the sun
- Do not use sunbeds, solariums and tanning lamps
- Examine your moles regularly
- Protect your children from sun damage with a hat, T-shirt and
- Have regular skin checks by your GP or dermatologist, especially
if new and persisting skin spots develop.
Things to remember
According to The Cancer Council:
- It is your right to seek a second opinion about any diagnosed
and proposed treatment for skin cancer. Your GP will refer you to
a dermatologist if s/he thinks it is necessary. You can arrange
to see a dermatologist without a GP referral but under Medicare
you will be rebated for a non-referred consultation. This means
that your rebate will be a smaller percentage of the total fee
- Your skin cancer (especially melanoma) should be treated promptly
- The risks associated with most treatments will be minor but may
include infection, pain and permanent scarring
- Whoever plans your treatment should also provide follow-up care