About Skin Cancer
What is Skin Cancer?
Skin cancer rates in Australia are higher than anywhere else in the world. It is the most common form of cancer in Australia, affecting all age groups.
In SA, the lifetime risk of developing a skin cancer is 1/33 for men and 1/36 for women.
Skin cancer is a type of cancer that begins in the basal layer of the epidermis.
There are three main types of skin cancer in Australia: basal cell carcinoma; squamous cell carcinoma and melanoma.
Melanomas start in the pigment cells (melanocytes) while basal and squamous cell carcinomas develop from the epidermal cells.
(Carcinoma is a term used for some types of cancer).
The skin is the largest organ of the body, it has several important functions.
1. It acts as a protective layer against injury and disease
2. It regulates our body temperature
3. It maintains our hydration
The skin consists of three layers:
• The epidermis, or the outer layer
• The dermis, or the inner layer
• The subcutaneous fat layer
The epidermis is made up of cells that produce keratin, a substance that covers the outside of the skin and resists heat, cold and the effects of many chemicals. The cells in the epidermis also produce melanin, the substance that gives our skin its colour. Melanin is able to absorb ultraviolet light and provide some protection from its damaging effects.
Types of Skin Cancer
Basal Cell Carcinoma
Basal cell carcinomas are the most common but least dangerous type of skin cancer. It accounts for about 75% of skin cancers. They grow slowly over months to years but if left untreated, a deep (rodent) ulcer may form. Fortunately, they very rarely spread to other parts of the body. If you have one basal cell carcinoma, you may have others; either at the same time or in later years. Basal cell carcinomas are most commonly found on the face, neck and upper trunk. They may appear as a lump or scaly area and are pale, pearly or red in colour. They may have blood vessels on the surface.
Squamous Cell Carcinoma
Squamous cell carcinomas are more dangerous than basal cell carcinomas. It accounts for about 20% of skin cancers.They usually grow over a period of weeks to months. These cancers may spread to other parts of the body (metastasis) if not treated promptly. Squamous cell carcinomas appear on areas of skin most often exposed to the sun. They have scaling, red areas which may bleed easily and ulcerate, looking like an unhealing sore. These common skin cancers generally occur in people over the age of 40. However, basal cell carcinoma can occur in younger adults. The major cause of these skin cancers is sun exposure over many years.
Melanoma is the rarest but most dangerous skin cancer. It accounts for about 5% of skin cancers.It is often a fast growing cancer which if left untreated, can spread quickly to other parts of the body to form secondary cancers or metastases. Melanomas can appear anywhere on the body, not only in areas that get a lot of sun. The first sign of a melanoma is usually a change in a freckle or mole, or the appearance of a new spot on normal skin. Changes are normally seen over a period of several weeks to months, not over several days. The changes are in size, shape or colour. Melanoma can occur from adolescence onwards and is most common between 30 and 50 years of age. In rare instances it may develop in children.
Signs and Symptoms
As skin cancers are visible, they can be checked as soon as they develop. Early symptoms may seem quite minor but any suspicious spot should be checked immediately.
The signs to look for are:
• A crusty, non-healing sore
• A small lump which is red, pale or pearly in
• A new spot, freckle or mole changing in
Causes of Skin Cancer
Everyone is at risk of skin cancer. People who burn easily and rarely tan are at the greatest risk. Unprotected skin, whether tanned or not, is likely to be damaged by the sun and may develop skin cancer later in life.
Childhood exposure to the sun is an important factor in the development of skin cancer later in life. Research also suggests there may be a link between sunburn in childhood and melanoma in adulthood.
Skin cancer is seen most often in fair skinned people who have lived in Australia all their lives. It is most common in people of Celtic (Scottish, Irish and Welsh) background. However it also occurs in people whose parents migrated from Southern Europe e.g. Greece or Italy.
People who work outdoors have a greater risk of developing the common skin cancers than indoor workers. This is because of their greater exposure to sunlight. Workers in some industries have to take precautions against other known causes of common skin cancers, such as arsenic, polycyclic hydrocarbons and a number of other chemicals.
Solar keratosis (sunspots) are dry, rough spots on the skin that are common in people over 40. They are not skin cancers but an indication that the skin has had enough skin exposure to develop skin cancer. People with keratoses should take particular care to protect their skin from the sun. they should also be examined to make sure a skin cancer is not present.
- Minimise your time in the sun between 10.00am – 3.00pm
- Use shade as much as possible when outdoors
- Wear protective clothing – a wide brimmed hat and cover-up clothing
- Apply SPF 30+, broad spectrum sunscreen to skin which isn’t covered by clothing