Skin cancer: what is it?
What is the skin?
Everyone knows what skin is. It covers a person from head to foot, is decorated with moles, freckles, wrinkles, pores, spots, and hair and comes in just about every colour except green and blue.
Actually, your skin is one of the organs of your body. Others include your heart, lungs, stomach and kidneys. Your skin is your biggest organ. It’s also different from the others in being on the outside of your body — which means it can be easily damaged by things in the environment.
Skin does lots of things. It helps protect you from injury, germs, and parasites. It’s waterproof. It helps stop your body drying out and from getting too hot or too cold. It contains nerve endings so you can feel what you touch, as well as things like heat and cold. It contains sweat glands to help cool you down when you’re too hot.
The deepest layer of the skin (the dermis) contains blood vessels, the roots of your hair (follicles), the muscles that make your hairs stand up when you're cold, and the oil-producing glands that keep your hair and skin from getting too dry.
The part of the skin you can see, the outer layer, is called the epidermis. New skin cells grow deep in the epidermis and work their way up to the surface. It’s in the epidermis that skin cancers can start.
What is skin cancer?
Skin cancer happens when some of the cells of the epidermis, the outer layer of a person's skin, begin to grow out of control.
There are 3 main types of skin cancer.
Basal cell carcinoma
If the cancer affects the cells at the lowest level of the epidermis, called the basal cells, the cancer is called basal cell carcinoma, or BCC for short. Basal means ‘at the bottom’.
Squamous cell carcinoma
If the cancer is found within the layer of flat cells just above the basal cells, it’s called squamous cell carcinoma, or SCC. Squamous means ‘like scales’. Both basal cell carcinoma and squamous cell carcinoma arise in cells from the basal layer.
Melanoma
If the cells affected are in the melanocytes, the cells in between the basal cells, it’s called melanoma. The melanocytes produce melanin, which gives the skin its colour. Dark-skinned people make more of it than light-skinned people. Melanoma is the most serious type of skin cancer, but it’s also the least common and it can be treated successfully if it is caught early.
‘Carcinoma’ is another word for certain types of cancer.
For further information and advice, call the Cancer Helpline on 13 11 20.
Last Reviewed: 01 August 2006
