Skin cancer: what is it?
What is skin cancer?
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 superficial cancer. Cancer that spreads deeply into the skin or to other parts of the body is known as invasive cancer.
What types are there?
There are three main types of skin cancer: basal cell carcinoma (BCC), squamous cell carcinoma (SCC) and melanoma. There are other rare skin cancers, such as those that start in the sweat glands and hair follices.
Basal cell carcinoma (BCC)
BCC makes up about 70% of non-melanoma skin cancers.
- 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 5cm, 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 accounts for about 30% of non-melanoma skin cancers.
- 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.
Bowen's disease is an early skin cancer that is often called squamous cell carcinoma-in-situ. The SCC cells are confined to the epidermis, and they usually appear as a red scaly patch.
Melanoma is the least common type of skin cancer but 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.
For information about melanoma, call the Cancer Council Helpline on 12 11 20 for a free copy of the Understanding Melanoma booklet.
A freckle or mole that itches, bleeds or becomes larger or irregular in shape may be a melanoma and should be seen by a doctor without delay.
How common is skin cancer?
Australia has the highest rate of skin cancer in the world. Two out of three people who spend their life in Australia will develop some form of skin cancer.
BCC (basal cell carcinoma) and SCC (squamous cell carcinoma) are the most common types of non-melanoma skin cancer. In Australia, about 370,000 cases of BCC and SCC are diagnosed and treated each year.
BCC can develop in young people but is most common in people aged over 40 years. SCC occurs mostly in people aged over 50.
More than 10,300 cases of melanoma are diagnosed in Australia each year.
What causes skin cancer?
The main cause of skin cancer is exposure to ultraviolet (UV) radiation.
The sun produces UV radiation but it can also come from other sources, such as solarium tanning machines.
Most parts of Australia have high levels of UV radiation all year round. This radiation cannot be seen or felt but can cause:
- premature ageing of the skin
- damage to the skin cells, which leads to skin cancer.
Skin cancer is related to two factors: a person’s total lifetime exposure to UV radiation and the number of sunburns they have had.
Research suggests that while skin cells are often damaged in childhood, it may be sun exposure in adulthood that triggers these damaged cells to turn cancerous.
Who is at risk?
Anyone can develop skin cancer, regardless of their skin colour or general health. However, some people have a higher risk of skin cancer than others.
You may be at higher risk if you have:
- numerous moles on your body
- dysplastic naevi
- a personal or family history of melanoma
- infrequent but intense periods of exposure to UV radiation, especially if it results in sunburn (such as on holidays or during recreational activity)
- fair skin that burns easily, freckles and doesn’t tan
- red or fair hair and blue or green eyes
- a weakened immune system, which could be due to taking certain drugs that suppress the immune system.
People with olive or dark skin have more natural protection against skin cancer because their skin produces more melanin than fair-skinned people. However, because UV radiation is so strong in Australia, dark and olive-skinned people still need to protect their skin. For information about protecting your skin, see page 17.
Talk to your doctor about your risks for skin cancer. Your GP or dermatologist can give you advice about checking your skin.
The best way to prevent skin cancer is to protect your skin from the sun and other sources of UV radiation (such as solariums).
- Wear clothing that covers as much of your skin as possible, including the back of your neck. Shirts with sleeves and a collar, trousers, and long skirts or long shorts that cover a large part of your legs are ideal. The best protection comes from closely woven fabric, as UV radiation can go through thin material.
- Use sunscreen with sun protection factor (SPF) 30+ that is broad spectrum and water resistant. Apply sunscreen 20 minutes before going out and reapply every two hours or after swimming or any activity that causes you to sweat or rub it off.
- Wear a hat that shades your face, neck and ears. Broad brim, bucket style and legionnaire style hats provide good protection. Baseball caps aren’t recommended. Adult hats should have at least an 8–10 cm brim.
- Use shade from trees, umbrellas, buildings or any type of canopy. Choose your shade carefully. UV radiation is reflective and bounces off surfaces such as concrete, water and sand, causing you to burn even when you think you’re shaded.
- Protect your eyes with sunglasses that meet the Australian Standard AS 1067 (check the tag). Wrap-around styles are best.
- Always protect your skin when the UV Index is 3 (moderate) or above (see page 12). UV levels are strongest between 11am and 3pm during daylight saving (10am and 2pm at other times of the year). During these hours, more than 60% of the sun’s UV radiation reaches the earth’s surface.
- Do not use tanning beds or sun lamps, which give off UV radiation that increases the risk of skin cancer.
- Babies and children have delicate skin and should be protected from direct exposure to sunlight. Use shade, umbrellas, clothing and hats to protect them. Apply SPF 30+ sunscreen to the areas of skin that cannot be covered with clothing, such as the face and the back of the hands.
Sunlight and health
Sunlight is important to your health. Vitamin D, which is needed to develop and maintain strong and healthy bones, is made when skin is exposed to UV radiation.
You only need to be in the sun for about 10 minutes on most days of the week, outside peak UV times, to produce enough vitamin D for good health. Most Australians get enough UV radiation from the sun just by going about their daily activities. If you don’t go outside much and are concerned about getting enough vitamin D, talk to your GP.
Getting a checkup
If you notice anything new or unusual on your skin, it is important to see your doctor immediately.
Your GP, who knows your medical history, can examine your skin (including areas that are not exposed to the sun). GPs can also treat some skin cancers, refer you to a specialist if necessary, and advise you on appropriate care.
Your GP may refer you to a skin specialist (dermatologist). A dermatologist is a doctor who has completed specialist training in preventing, diagnosing and treating skin diseases, including skin cancer.
If you would like a consultation with a dermatologist, you should keep the following in mind:
- You should have a referral from a GP. You can arrange to see a dermatologist without a GP referral but under Medicare you will be billed for a non-referred consultation. This means that you will not be reimbursed and you will have to pay for the appointment.
- With or without a referral, you should ask before the appointment what fees may be charged and what proportion is covered by Medicare.
- There may be a long waiting list. If there is a spot on your skin of particular concern, your referring doctor can request an early appointment.
- If you live in regional NSW, there may not be a dermatologist based in your local area. However, many regional areas have visiting dermatologists. Your GP should be able to advise you. If a melanoma is suspected, the GP may be able to remove the spot or refer you to a dermatologist, local surgeon or specialist melanoma centre.
Skin cancer clinics
There are many skin clinics that offer a variety of services and fee arrangements. Clinics are usually operated by GPs who have an interest in skin cancer but some clinics are operated by dermatologists. Practices may offer bulk-billing for some services.
Some skin clinics may offer a higher level of expertise in skin examination than others, but at this stage there is no reliable way to evaluate the quality of care provided.
Choosing a skin clinic
There are four main points to consider when choosing and attending a skin clinic:
- qualifications and experience of the medical staff
- diagnosis and treatment services offered
- information and follow-up provided.
For more information on choosing a skin clinic and for a copy of the Getting Your Skin Checked flyer, call the Cancer Council Helpline on 13 11 20.
Cancer Council does not operate or endorse any particular skin clinics or doctors.