What is Skin Cancer?
The word cancer refers to the abnormal and uncontrolled growth of cells that have the potential to invade surrounding tissues (skin, fat, bone, etc.) or spread to distant tissues or organs. There are various types and stages of skin cancer and not all are equal in the way they appear, grow or are managed. Sun damage has been implicated in almost all forms of skin cancer so the majority of skin cancers can be prevented with adequate sun protection.
Actinic keratosis (also referred to as solar keratosis) are sun-induced spots that carry a risk of progressing to become skin cancer. Actinic keratosis appear as white or red flaky spots in chronically sun-exposed areas. While some people might have a few distinct lesions, others may have ‘field actinic damage’ meaning that an entire area is covered with numerous lesions. Treatment is not always necessary and is usually guided by patient factors.
It is never too late to protect yourself from the damaging effects of UV radiation produced by the sun. A sunscreen with SPF 30+ or higher with UVA/broad spectrum cover should be used. Sunscreen should be re-applied in a thick layer every two hours if outdoors. It is important to apply sunscreen well before your planned sun exposure as most sunscreens take at least 20 minutes to become activated on your skin. A broad-brimmed hat should be worn to protect your face, scalp, neck and ears. Long sleeves and pants provide additional sun protection. Clothing material should be tightly woven so that you are unable to see through the clothing when it is held up against the sun. Download the Cancer Council’s Sunsmart app on your phone for further information and to receive UV alerts.
Types of skin cancer
Basal cell carcinoma (BCC)
Basal cell carcinoma is the most common type of skin cancer encountered by dermatologists. They come in a variety of different forms and not all BCCs appear or are treated the same way. While some BCCs appear as a red pimple-like growth, others, like superficial BCCs, can appear as a red, flat, scaly patch of skin. Superficial BCCs can be treated with non-surgical options. Morpheic BCCs (also known as sclerosing and infiltrating BCC) are unique in that they may have a scar-like appearance and can grow ‘roots’ in the skin making it more difficult to treat.
Squamous cell carcinoma (SCC)
Squamous cell carcinoma is another common type of skin cancer. Squamous cell carcinomas differ in how quickly they grow and how aggressive they can be. Less commonly, SCCs may grow into surrounding nerves. Squamous cell carcinomas on the lip and ears can be more concerning as they are more prone to spreading to other parts of the body.
Also known as in-situ SCC and intraepidermal carcinoma, Bowen’s disease is an early form of SCC where the cancerous cells are limited to the top layer of the skin. They carry a small risk of developing into a full-blown invasive SCC. Various treatment options are available to treat Bowen’s disease and surgery is not always required.
Melanoma is by far the most well-known and publicised type of skin cancer. If detected and treated early, the prognosis of melanoma can be very favourable. As in other types of skin cancer, there are many forms of melanomas and not all appear or behave the same way. Your risk of developing a melanoma is dependent on many factors and can be calculated using the Victorian Melanoma Service risk calculator.
Other rarer forms of skin cancer also exist.
Treatment of skin cancer
Not all skin cancers are treated in the same way. While some need to be cut out completely, others can be scraped off, frozen or treated with creams, light and laser-based therapies. Some skin cancers may require further treatments such as radiotherapy.
Liquid nitrogen (Cryotherapy)
Liquid nitrogen (cryotherapy) can be used to treat several types of skin lesions. Liquid nitrogen can be applied either with cotton wool or using a special spray gun. The intensity of the treatment depends on the type of skin lesion that is being treated. The treatment may sting and cause some mild discomfort. Within the first few hours, the area will become red and swollen, and a blister may develop. If the blister is tense, this can be pierced with a sterile needle to allow the fluid to drain. Various ointments can be used to speed up the healing process. In most cases, the area heals within 2-3 weeks. If the treated area does not clear up within 4-6 weeks you may need re-treatment or have a skin biopsy.
Curettage is a procedure commonly performed by dermatologists. Under local anaesthetic, a pen-like device with a loop on the end is used to scrape the top layer of the skin (where the skin cancer is present). The area is then cauterized (this makes a funny noise and produces a mild odour) and the scraping is repeated. The wound can take a few weeks to heal and in much the same way as a deep graze. The specimen is sent to a pathology lab where it is looked at under a microscope by a pathologist.
Excisional surgery is a procedure commonly performed by dermatologists. Under local anaesthetic, your tumour is cut out as an oval shape so that it can be stitched up without the ends puckering. The specimen is sent to a pathology lab where it is looked at under a microscope by a pathologist. At times, the skin cancer is cut out as a circle, and a skin graft or skin flap is used to close the wound. The wound can take several weeks to heal.
While not all skin cancers can be treated with creams, for some forms and pre-cancerous lesions, creams can be very effective. There are a variety of creams available for different types of skin cancer with various advantages. These creams work by either stimulating your own immune system, directly destroying the cancerous cells on the skin or a combination of both. It is important to discuss this with your dermatologist and determine whether you are a suitable patient for the use of creams and whether they can be effective for your type of skin cancer.
Photodynamic therapy and laser treatments
Pre-cancerous lesions such as actinic keratoses and some early forms of skin cancer can be treated using a specialised technique called photodynamic therapy. This involves lightly scraping the area followed by applying a specialised cream. The cream is absorbed by the abnormal cells and then activated using either daylight, a special red light or laser. One to two treatment sessions may be required. Some lasers can be used to strip off the top layers of the skin to remove precancerous lesions.
Prevention and early detection of skin cancer
Australia has one of the highest rates of skin cancer in the world. Looking after your skin should be one of your top priorities.
Approximately 2 in 3 Australians will have at least one skin cancer by the time they turn 70. Skin cancer can also be seen in much younger individuals. It is therefore important that you become familiar with your skin and the spots on them. Unlike internal organ cancers, skin cancer detection does not require x-rays, CT scans or ultrasound because we can directly visualise the skin by the naked eye and with a special magnifying tool called the dermatoscope. Any suspicious skin lesions can be sampled by a biopsy.
Sun protection includes the regular use of sunscreens, broad-brim hats, long sleeves and pants, wearing sunglasses and seeking shade where possible. Sun protection is suggested when the UV index rises above 3. It is important to be aware that it is not the heat generated by the sun that causes sunburn and skin cancers, but rather the UV rays. The UV index can be as high as 15 even on cool and cloudy days. Download the Cancer Council’s SunSmart app on your phone for further information and UV alerts.