Basal cell carcinoma and squamous cell carcinoma
This information has been written to help you understand more about the two most common types of skin cancer: basal cell carcinoma (BCC) and squamous cell carcinoma (SCC).
We cannot advise you about the best treatment for you. You need to discuss this with your doctors. However, we hope this information will answer some of your questions and help you think about other questions you want to ask your doctor.
The skin has many important jobs. It protects us from injury, cools us when we get hot and prevents us from becoming dehydrated. The skin has two main layers: the epidermis and the dermis. The epidermis is the top or outer layer.
- It contains two main types of cells: squamous cells and melanocytes.
- The melanocytes produce melanin, the substance that gives skin its colour (pigment).
- When skin is exposed to sunlight, the melanocytes produce more melanin and the skin becomes tanned.
The dermis is underneath the epidermis.
- It contains the roots of hairs, glands that make sweat and oil, blood and lymph vessels and nerves.
Types of skin cancer
Skin cancers are named after the type of cell they start from.
- Basal cell carcinoma and squamous cell carcinoma are the two most common types of skin cancer. They are sometimes called non-melanoma skin cancer.
- The third most common type of skin cancer is melanoma, which begins in the melanocytes.
- There are other rare skin cancers, such as those that arise from the sweat glands.
Basal cell carcinoma
- About 70% of all skin cancers.
- Most common in people over 40 years old, but can develop in younger people.
- Usually develops on the head, neck and upper body. Some appear on the arms and legs.
- Small, round or flattened in shape. Can be scaly and dry.
- Red, pale or pearly in colour.
- Slow growing.
- Doesn’t usually spread to other parts of the body.
- If left untreated, it may grow deeper into the skin and damage nearby tissue. This may make treatment more difficult and increase the chance of the skin cancer coming back.
Squamous cell carcinoma (SCC)
- About 30% of all skin cancers.
- Most common in people aged over 50.
- Usually appears on the head, neck, hands and forearms. Less often, it can develop on the upper body or the legs.
- Thickened red, scaly spots, which later may bleed easily or be tender to touch. They can look like a sore that hasn’t healed.
- Grow quickly over several months.
- Can spread to other parts of the body. SCCs on the lips or the ears have a high risk of spreading and should be seen by a doctor immediately.
- About 2% of all skin cancer cases.
- Most serious but can be treated successfully when diagnosed early.
- Can appear as a new spot, or a an existing freckle or mole may change in size, shape or colour.
- Irregular edge or surface, blotchy with brown, black, blue, red, white or light grey colour.
- May itch, bleed or becomes larger or irregular in shape.
- Normally noticed over several weeks or months rather than days.
More information on melanoma is provided here.
Other spots to watch for
You should watch your for other spots on your skin. They are not skin cancer, but they can be warning signs that your skin has received too much sun and you may be more prone to melanoma or other skin cancers.
Solar keratoses (sunspots)
- Usually occur in people aged over 40.
- Appear on the head, neck, arms and legs.
- Usually flattish, scaly patches.
- May be pale or red, and sting if scratched.
- Some may develop into squamous cell cancers.
- Naevi are growths on the skin, also called moles. Moles are very common.
- Moles that are irregular in shape and an uneven colour are dysplastic naevi.
- People with many dysplastic naevi are more likely to develop melanoma.
If you have dysplastic naevi or solar keratoses, you should regularly check for any changes and look for new spots on the skin. If you notice any changes, you should see your doctor immediately.
What causes skin cancer?
Australia has the highest rate of skin cancer in the world. One in two people who spend their life in Australia will develop some form of skin cancer. Unprotected exposure to ultraviolet (UV) radiation — from the sun or other sources, such as tanning machines in solariums – remains the most important risk factor for skin cancer. UV radiation cannot be seen or felt but can cause:
- early ageing of the skin
- damage to the skin that builds up over time and can lead to skin cancer.
Skin cancer is usually related to lifetime exposure to UV radiation. Most parts of Australia have high levels of UV radiation year round.
While skin cancer usually appears in older adults, the damage begins at an early age from exposure to UV radiation, especially sunburn.
New research suggests that while cells are often damaged in childhood, it may be sun exposure in adulthood that triggers cells to turn cancerous.
Who is at risk?
Anyone can develop skin cancer. The risk is increased if a person:
- has numerous moles (naevi) on their body
- doesn’t protect their skin from the sun, or spends a lot of time in the sun (e.g. working outdoors)
- has a personal or family history of melanoma
- is infrequently, but intensely exposed to the sun (e.g, on holiday or during recreational activity), especially if it results in sunburn
- has fair skin that burns easily, freckles or doesn’t tan
- has red or fair hair and blue or green eyes
- has solar keratoses (sunspots) or dysplatic naevi
- a compromised immune system, possibly due to taking certain drugs after an organ transplant or being HIV positive.
People with dark or olive skin have more protection against skin cancer because they produce 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 can I prevent skin cancer?
The best way to prevent skin cancer is to protect your skin from the sun. You can do this by:
- Knowing the UV index, which shows the intensity of the sun’s rays. When the UV index is 3 (moderate) or above, the sun levels are high enough to cause skin damage and sun protection is required. You can check the daily SunSmart UV Alert in most daily newspaper weather forecasts or online.
- Staying out of the sun between 11am and 3pm during daylight saving hours (10am and 2pm at other times of the year) when the sun is strongest. During these hours, more than 60% of the sun’s UV radiation reaches the earth’s surface.
- Using shade from trees, umbrellas, buildings or any type of canopy. Remember to choose your shade carefully. UV radiation is reflective and bounces off surfaces like concrete, water and sand, causing you to burn even when you think you’re protected.
- Wearing clothing that covers as much of the skin as possible, including the back of the neck. A shirt with long sleeves and a collar, trousers, skirts or long shorts that cover the legs or a large part of them are recommended. The best protection comes from closely woven fabric.
- Wearing a hat that shades the face, neck and ears. Hats should have at least an 8-10cm brim.
- Using sunscreen with sun protection factor (SPF) of 30+, and which is also broad spectrum and water resistant, no matter what type of skin you have. Apply sunscreen 20 minutes before going out into the sun and reapply every two hours or after swimming or any activity that causes you to sweat or rub it off.
- Protect your eyes with sunglasses that meet the Australian Standard AS 1067 (check the tag). Wrap-around styles are best.
- Taking care to protect infants and young babies from direct exposure to sunlight. Use shade, umbrellas, clothing and hats to protect them. If necessary, use SPF30+ sunscreen on the areas of skin that cannot be protected naturally, such as the face and the back of the hands.
- Not using tanning bed and sun lamps, which give off UV radiation that can increase the risk of skin cancer.
Some 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. However, 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.
How do I know if I have skin cancer
- Get to know your skin.
- Check your skin four times a year – check your whole body, including the soles of your feet, between the toes and your nails.
- Use a mirror or ask a friend or relative to check areas that are hard to see, such as your back, or the back of your legs.
- To help you remember, keep a record of the date you last checked your skin, or check each time there is a change of season.
- You can also ask your doctor to check your skin or for a referral to a dermatologist.
The more often you examine your skin, the more you will learn about it – what is normal for you and what has changed since the last time you looked. Skin cancers don’t all look the same. Signs to look for include:
- a new spot that is different from other spots on the skin around it
- a sore that doesn’t heal
- a spot, mole or freckle that has changed in size, shape or colour.
If you notice anything new or unusual on your skin , it is important to see a medical professional immediately.
Who to see
Your general practitioner
Your GP knows your medical history, can examine your skin and advise you on appropriate care.
A specialist dermatologist
Your GP may suggest you see a specialist such as a dermatologist. A dermatologist is a doctor who has completed specialist training in preventing, diagnosing and treating skin disease, including skin cancer.
Several dermatologists work at the Sydney Cancer Centre who specialise in skin cancer.
Your doctor will first look at the suspicious spot, mole or freckle. If he or she suspects skin cancer, a biopsy will most likely be done to confirm the diagnosis.
A biopsy is a quick and simple procedure.
Your GP may do it, or refer you to a specialist.
The doctor will give you a local anaesthetic and cut out the spot. You will usually have a stitch or stitches to help the wound to heal.
The tissue that is cut out will be sent to a laboratory where a pathologist will examine it under a microscope. It will probably take at least a week for the results of your tests to be ready. This waiting period can be an anxious time. The results from your biopsy will help work out the treatment options.
Your doctor will consider a number of factors to determine the best treatment for your skin cancer, including:
- the location of the cancer
- its size
- whether it has spread to other parts of your body.
Treatment usually involves surgery or a combination of the methods described in this chapter.
Often the cancer is removed with the biopsy and no further treatment is needed. If the skin cancer is large or has spread beyond the surface of the skin, more tissue needs to be removed. You may need a skin graft. This means a piece of skin is taken from another part of your body and put over the area where the skin tissue was removed to close up a wound that is too big for stitches. Neighbouring skin may be rotated to cover the wound so there is a good match with the colour and texture of your normal skin. This is called a skin flap.
- Mohs (microscopically controlled surgery) technique is a highly specialised type of surgery.
- The cancer is removed little by little and checked under the microscope immediately. The removal continues until only healthy tissue remains.
- Mohs surgery is used to treat large skin cancers or those that have come back.
- Also used for skin cancers in areas that are difficult to treat, like near the eye.
- A freezing technique used for sunspots and superficial BCCs.
- Liquid nitrogen is sprayed over the growth to freeze and kill the skin.
- The wound will be slightly sore and red for a few days and may develop a blister. Later the dead tissue will fall off. Healing can take up to a few weeks. A white scar may form in the area.
Curettage with cautery
- Mainly used for superficial BCCs.
- A local anaesthetic is given around the lump or spot, and the cancer is scooped out with a small sharp instrument called a curette.
- Electric current is then applied (cautery) to stop bleeding in the area and to destroy any remaining tumour.
- The wound should heal within a few weeks, leaving a pale scar.
- A cream that destroys the skin cancer by stimulating the body’s immune system to fight the cancer.
- The cream is applied 5-7 times a week for up to six weeks.
- The skin will become red and sore during treatment.
Photodynamic therapy (PDT)
- A special cream is applied to the skin cancer, and a light is shone on the area.
- The cream and the light act together to destroy the cancer cells.
- May need to be repeated in 2-4 weeks.
- May be painful — you may be able to have a local anaesthetic.
- Treats cancer by using x-rays to kill cancer cells.
- Usually used in areas that are hard to treat with surgery, such as near the eyes, nose or forehead, or for skin cancers that have grown too far into the skin.
- Usually given over several weeks.
- Skin in the treatment area may become red and sore after 2-3 weeks of treatment.
For some people, the cancer may recur in the same spot or require further treatment. If the wound doesn’t heal or if you notice any other changes, see your local doctor or dermatologist.
It is important to continue to check your skin for changes, to visit your doctor for regular checkups, and to protect your skin from the sun. Make skin protection a part of your lifestyle throughout the year, not just in summer.
Will I get other skin cancers?
If you have been treated for skin cancer or sunspots, you have a high chance of developing new skin cancers. Sun damage to your skin by the sun has built up over the years and can’t be repaired.
Check your skin regularly for changes. See your local doctor or dermatologist if you notice anything new or unusual.