Understanding Skin CancerDownload this book (pdf, 898.07 kb)
Skin Cancer: Q&A
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.
There are two main types of non-melanoma skin cancer:
- basal cell carcinoma (BCC)
- squamous cell carcinoma (SCC).
There are other rare skin cancers, such as those that start in the sweat glands and hair follicles.
Basal cell carcinoma (BCC)
- 70% of non-melanoma skin cancers.
- Commonly develops on the head, neck and upper body.
- May appear as a pearly lump or a scaly or dry area that is pale or pink in colour.
- 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.
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)
- 30% of non-melanoma skin cancers.
- 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.
- Often appears as a thickened, red, scaly lump.
- 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.
Early skin cancer is sometimes called squamous cell carcinoma in-situ or Bowen's disease. The SCC cells are confined to the epidermis, and they usually appear as a red scaly patch.
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.
- About 370,000 cases of BCC and SCC are diagnosed and treated each year.
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
- 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.
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.
How do I know if I have skin cancer?
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
- a spot, mole or freckle that has changed in size, shape or colour
- a sore that doesn't heal
- a 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 GP or a dermatologist straightaway. Some spots on your skin (such as moles, sunspots or freckles) are warning signs that your skin has had too much sun exposure.