The skin is the largest organ in the body. It covers the body, protecting it from injury, regulating its temperature and preventing it from becoming dehydrated. Skin, like all other body tissues, is made up of cells. It has two main layers called the epidermis and the dermis.
The epidermis is the top, outer layer of the skin. It contains three different kinds of cells:
- Squamous cells - flat cells that are packed tightly to make up the top layer
- Basal cells - tall cells that make up the lower layer
- Melanocytes - cells that produce a dark pigment called melanin, the substance that gives skin its colour
Basal cells multiply constantly and the older cells move upwards in the epidermis. When they flatten out and form a layer they become squamous cells. The top layer of your skin is made up of dead skin cells which eventually fall off. When skin is exposed to the sun, melanocytes make extra melanin to protect the skin from getting burnt. This is what causes skin to tan. Melanocytes are also in non-cancerous (benign) spots on the skin called moles or naevi. Most moles are brown, tan or pink in colour and round in shape.
The dermis is the layer underneath the epidermis. It contains the roots of hairs; sweat glands; blood and lymph vessels; and nerves.
Image courtsey of Cancer Council Victoria
Skin cancer is the uncontrolled growth of abnormal cells in the skin. Cancer that only affects cells in the skin's top layer is called in-situ cancer. Cancer that spreads deeply into the skin or to other parts of the body is known as invasive cancer. There are three main types of skin cancer: basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and melanoma. There are other, rarer skin cancers too.
Basal cell carcinoma (BCC)
BCC makes up about two-thirds (66%) of non-melanoma skin cancers.1
- BCC commonly develops on the head, neck and upper body
- It may appear as a pearly lump or a scaly or dry area that is pale or pink in colour
- BCC may bleed and become inflamed, and dead tissue may slough off (ulcerate). Some BCCs heal then break down again
BCCs tend to grow slowly and don't usually spread to other parts of the body. However, if BCC is left untreated or grows larger than 5 cm, it may grow deeper into the skin and damage nearby tissue. This may make treatment more difficult and increase the chance of the BCC returning.
Squamous cell carcinoma (SCC)
SCC accounts for about one-third (33%) of non-melanoma skin cancers.1
- SCC usually appears on areas of the skin that are most often exposed to the sun, such as the head, neck, hands, forearms or lower legs
- It often appears as a thickened, red, scaly lump
- SCC may look like a sore that hasn't healed
SCCs tend to grow quickly over several weeks or months. It is possible for SCCs to spread to other parts of the body - SCC on the lips, ears, scalp or temples has a high risk of spreading and should be seen by a doctor immediately.
Melanoma is the least common type of skin cancer, (accounting for approximately 1-2% of cases), but it is the most serious. Normal, healthy freckles or moles usually have a smooth edge and an even colour. Melanoma often has an irregular edge or surface, and it may be blotchy and brown, black, blue, red, white or light grey. Left untreated, a melanoma may spread deeper into the skin where cancer cells can escape and be carried in lymph vessels or blood vessels to other parts of the body.
How common is it?
At least 2 in 3 Australians will be diagnosed with skin cancer before the age of 70. The risk is higher in men (2 in 3) than in women (3 in 5).2
1304 melanoma cases were reported in WA in 2014, making melanoma the third most common cancer type.3
Most people living in Australia are at risk of developing skin cancer. You are at higher risk of developing skin cancer if you have:
- Fair skin that burns easily and does not tan
- Blue or green eyes and/or fair or red hair
- Suffered sunburn as a child
- Spent your childhood in Australia
- A large number of freckles or moles
- A family or personal history of skin cancer
- Used a solarium
- Worked or spent a lot of leisure time in the sun
Ultraviolet (UV) radiation from the sun
Sun exposure is the cause of around 99% of non-melanoma skin cancers and 95% of melanoma skin cancers in Australia.4, 5
There are two types of UV radiation that reach the Earth's surface - UVA and UVB. UV radiation causes sunburn, premature ageing of the skin, eye damage and skin cancer.
Each time your unprotected skin is exposed to UV radiation, it changes the structure of the DNA in the skin cells. Overexposure to UV radiation permanently damages the skin and the damage gets worse with each exposure to UV radiation.
Sun protection throughout our lives is important, particularly during childhood. UV exposure in childhood greatly increases the chance of getting melanoma later in life because the damaged cells have time to grow and develop into cancer.
UV radiation from solariums (sunbeds or sunlamps)
A solarium is an artificial tanning device that uses electricity to produce UV radiation to tan the skin. Solariums expose the user to UVA and UVB radiation, increasing their risk of developing skin cancer.
Cancer Council WA does not recommend using solariums for cosmetic tanning under any circumstance. Commercial solaria are now banned in every Australian state and territory (except the Northern Territory where there are no commercial solaria in operation). Find out more about solarium tanning.
In Australia, sunburn can occur in as little as 10 minutes on a fine summer day. Sunburn at any age, whether serious or mild, can cause permanent skin damage.
Sunburn is a major risk factor for developing melanoma, the most dangerous form of skin cancer. Melanoma is more likely to occur in people who are exposed to the sun every now and then (e.g. on weekends or holidays, especially if they get sunburnt), not a little bit every day.
However, people who have accumulated a lot of sun exposure continuously (e.g. outdoor workers) are also at increased risk.
The skin cells in the epidermis (the top layer of the skin) produce a pigment called melanin, which gives skin its colour.
When skin is exposed to UV radiation more melanin is produced, causing the skin to darken or 'tan'.
Having a tan is a sign that the skin has been overexposed to UV radiation and damage has occurred, putting you at an increased risk of developing skin cancer. Even a light tan shows that the skin has been damaged. Too much UV radiation also makes you look old before your time - making your skin look saggy, wrinkly and leathery.
Some people think it's safe to tan, as long as they don't burn. This is not true - there is no such thing as a healthy or safe tan.
Skin cancers don't all look the same but there are some signs to look out for a:
- spot that is different from other spots on the skin
- spot, mole or freckle that has changed in size, shape or colour
- sore that doesn't heal
- spot that bleeds
It's important to get to know your skin. Examining your skin will help you notice changes and learn what is normal for you. If you see anything new or different on your skin, see your doctor or a dermatologist straightaway. Skin cancers that are found and treated early will need less invasive treatment and have a better outcome (prognosis).
The warning signs of UV damage to the skin and eyes
The following conditions are not cancer but may increase your chances of skin cancer or be a warning sign that damage to the skin or eyes has occurred.
- Are odd shaped (also called atypical) moles that aren't cancer but may indicate a greater risk of developing melanoma
- Usually 5-10mm wide, with uneven colouring
- If you have lots of odd shaped moles you are at a higher risk of developing skin cancer and should have your skin checked regularly by your doctor
- Generally hard, red, scaly spots on sun exposed areas of the skin
- Occur commonly on the head, neck and the backs of the hands
- Are a warning sign that the skin has been damaged by the sun and that skin cancers may develop
Sun exposure can cause burns to the eye similar to sunburn of the skin which may lead to:
- cataracts (clouding of the lens);
- pterygium (tissue covering the cornea); and
- cancer of the conjunctiva or cornea
Skin cancer is largely preventable. By following five simple sun protection steps, you can reduce your risk of skin cancer.
Protect yourself in five ways from skin cancer
1. Slip on protective clothing
2. Slop on SPF 30 or higher sunscreen
Sunscreen should not be relied upon as the only form of sun protection.
No sunscreen provides 100% UV protection - remember to use in combination with protective clothing, hats and sunglasses.
Look for a sunscreen that:
Cancer Council recommends using sunscreen every day when the UV index is forecast to be 3 or above. Sunscreen should be incorporated into your daily morning routine on these days.
3. Slap on a hat
Slap on a hat that provides as much shade as possible to your face, head, neck, ears and eyes.
There are three main styles of hats that provide adequate sun protection:
4. Seek shade
Staying in the shade is one of the most effective ways to reduce sun exposure, but remember:
5. Slide on some sunglasses
Sunglasses can protect your eyes against UV radiation.
When to use sun protection
The best way to know when you need to use sun protection is to use the UV Index. The UV Index is a simple measure of the UV radiation level at the Earth's surface. It has been designed to help people to avoid overexposure to high levels of UV radiation. The values of the Index range from zero upward and the higher the Index value, the greater the potential for damage to the skin and eyes, and the less time it takes for harm to occur.
You need to use sun protection when the UV Index is 3 or above, and when the UV Index reaches 8 or above you should take extra care and stay out of the sun if this is possible.
Over 95% of skin cancers can be treated if found early. Most skin cancers are detected by people themselves or by a family member. Skin cancers may not be painful and are more commonly seen rather than felt.
It's important to get to know your skin and what is normal for you so changes will be quickly noticed. All Australians, particularly those aged 40 and over, should check their skin regularly.
When checking your skin:
- Make sure you check your entire body as skin cancers can sometimes occur in parts of the body not exposed to the sun, for example soles of the feet, between fingers and toes and under nails
- Undress completely and make sure you have good light
- Use a mirror to check hard-to-see spots, like your back and scalp, or get a family member or friend to check it for you
You should look for:
- a spot that is different from other spots around it;
- an new or existing skin spot that has changed in size, shape or colour: and/or
- a non-healing sore.
If you are concerned about your skin cancer risk or notice anything on your skin that has changed in size, shape or colour or a non-healing sore, see your doctor straight away. Your doctor can discuss your skin cancer risk and advise you on your need for medical checks or self-examination.
For more information about screening and early detection of skin cancer, see Cancer Council Australia's Screening and early detection of skin cancer position statement.
The ABCDE of melanoma detection
Using the ABCDE of melanoma detection check spots on your skin for:
If the spot or lesion is divided in half, the two halves are not a mirror image.
A spot or lesion with a spreading or irregular edge.
A spot or lesion with a number of different colours through it.
The spot or lesion is usually greater than 6mm across. However, suspect lesions of smaller diameter should also be investigated.
A spot or lesion that changes over time (size, shape, symptoms, surface, colour).
If you are suspicious of a spot or would like to have your skin checked, there are a number of things you can do.
See your doctor - your doctor knows your full history, can examine your skin and advise you on appropriate care.
See a specialist - if you would like a second opinion ask your doctor to refer you to a specialist such as a dermatologist. A dermatologist is a doctor who has completed additional training to specialise in diagnosing and treating skin disease, including skin cancer.
Skin and mole clinics - the Cancer Council does not endorse any particular skin checking clinics in Western Australia. There are many skin clinics, offering a variety of services and fee arrangements. Skin clinics are usually operated by doctors and some, but not all, offer bulk billing for at least some of their services. Research shows skin cancer clinics may not necessarily offer a higher level of expertise than your family doctor. In deciding whether to go to a skin clinic, it is important you find out about the services offered and the expertise of the staff.
What you should expect in a skin check - a thorough skin check should:
- include some consideration of your family history of skin cancer
- consider your personal sun exposure history
- consider your skin type
- require you to strip to your underwear so the doctor / specialist can check your skin
- take between 5 and 10 minutes
Why the Cancer Council does not endorse skin check services
Commercial skin check providers regularly approach Cancer Council for endorsement of their services.
Some of these are doctor clinics and are no different than any doctor service provider. Cancer Council cannot promote one doctor service provider (or group of them) over another.
Secondly, Cancer Council does not have the resources to monitor the quality of service provided by all skin check providers in order to make sound recommendations. Instead, we provide information that will allow you to make an informed decision about your own choice of skin check provider.
Your doctor will first look at the suspicious spot, mole or freckle. If a skin cancer is suspected, they may take a biopsy under a local anaesthetic to make a definite diagnosis. A biopsy involves removing a sample of cells and examining them under a microscope.
If a melanoma is suspected, x-rays, scans and/or blood tests may be used to check whether there are any signs that the cancer has spread.
This can be a worrying time, especially if you need to have several tests. If the tests show you have or may have skin cancer, your doctor will refer you to a specialist, who will talk to you about treatment options.
A biopsy is a quick and simple procedure. Your doctor or specialist will give you a local anaesthetic to numb the area. A sample will be taken from the skin spot or the spot will be completely cut out. You will usually have stitches to close the wound and help it heal. The tissue that is cut out will be sent to a laboratory where a pathologist will examine it under a microscope. It takes about a week to receive the test results. If all of the cancer is removed during the biopsy, this will probably be the only treatment required.
What to ask your doctor
A cancer diagnosis can be very confusing time. There are several things you can do to help prepare for your appointment and to improve your understanding.
- It can be helpful to write a list of questions to ask your doctor or specialist. You may need to ask for a longer appointment.
- Take some paper and a pen so that you can write down notes and instructions
- Take a relative or friend with you for support - it can be helpful to have an extra person to hear what is being said and write down any notes
- It may be helpful to record your visit - make sure you ask your doctor if it's okay. Remember, many smart phones and mp3 players can make audio recordings.
If you have been diagnosed with skin cancer, you may be cared for by a multidisciplinary team (MDT). This is a group of doctors and other health professionals who are experts in a specific cancer who work together to plan the best treatment for you. Everyone's treatment is different and depends on the type of skin cancer and how far the cancer has spread.
Stages of cancer
The staging system used for skin cancer is the TNM system, which describes the stage of the cancer from stage I to stage IV.
- T (Tumour) indicates the depth of the tumour invasion - the higher the number (between 1 and 4), the further the cancer has spread.
- N (Nodes) indicates whether the lymph nodes are affected - a number between 0 and 3 describes how much the cancer has spread to lymph nodes near the bladder.
- M (Metastasis) indicates whether the cancer has spread to other parts of the body - M1 means the cancer has spread to other organs or lymph nodes that are not near the bladder; M0 means there is no sign of the cancer spreading to other parts of the body.
This information is combined to describe the stage of the cancer from stage I to stage IV.6
If an excised skin cancer is thick, a biopsy of the first draining lymph node (sentinel node) is performed. The most important feature of a melanoma in predicting its outcome is its thickness. The presence of ulceration also predicts a poor outcome.7
Prognosis means the expected outcome of a disease. In most cases, the earlier skin cancer is diagnosed and treated, the better the outcome.
You may wish to discuss your prognosis and treatment options with your doctor, but it's not possible for any doctor to predict the exact course of your cancer. Test results, the type of cancer you have, the rate and depth of tumour growth, how well you respond to treatment, and other factors such as age, fitness and medical history are all important in assessing your prognosis.
Types of treatment
The type of treatment for skin cancer depends on the stage at diagnosis and can be different for everyone. Although nearly all treatments have side effects, most can be effectively managed. Ask your doctor to explain what side effects to expect and how best to manage these.
Sometimes the skin cancer is removed with the biopsy and no further treatment is needed. However, if some skin cancer remains after your biopsy, you will need other treatment.
Your doctor or specialist will advise you of the best treatment taking into account the type and size of the cancer, its location, your age, general health and your treatment preference. Possible treatments include:
Surgery involves removing the cancer as well as surrounding tissue to make sure no part of the cancer is left behind.
For those whose cancer has spread to the lymph nodes, the best results are often achieved by combining surgery with radiation therapy and chemotherapy.
Creams such as Imiquimod destroy the skin cancer by stimulating the body's immune system to fight the cancer.
Cryotherapy uses liquid nitrogen to rapidly freeze the cancer off.
Photodynamic therapy involves a special photosensitising cream being applied to the skin cancer and then exposed to a specific wavelength of light. The light interacts with the cream to destroy the cancer cells.
Curettage and cautery is when the cancer is scraped out and electric current is applied to stop bleeding and destroy any remaining tumour tissue.
Radiation uses electromagnetic radiation to destroy cancer cells. It can be used before or after surgery for cancer to reduce the tumour size and make surgery easier. It is also used to decrease the chance of cancer coming back.
After treatment, regular check-ups are needed for early detection of any new skin cancers.
If you notice any spots you are worried about between follow-up appointments it is important to speak with your doctor or specialist as soon as possible.
Complementary therapies can work alongside medical treatments and some have been shown to improve quality of life or reduce pain. There is no evidence that these therapies can cure or prevent cancer.
It is important to know that some complementary therapies have not been tested for side effects, may work against your medical cancer treatment and may be expensive. Let your doctor know about all complementary therapies you are thinking of using.