Skin Cancer / Melanoma

Below are common warning signs for the three main types of skin cancer.

Melanoma

• A mole that changes in colour, size, or that bleeds
• A small, dark, multicolored spot with irregular borders, either elevated or flat, that may bleed and form a scab
• A cluster of shiny, firm, dark bumps
• A mole larger than a pencil eraser
• Dark lesions on your palms, soles, fingertips or toes, or on mucous membranes lining your mouth, nose, vagina or anus

Basal cell carcinoma

• A pearly or flesh-colored oval bump with a rolled border, which may develop into a bleeding ulcer
• A smooth red spot indented in the centre
• A reddish, brown, or bluish black patch of skin on the chest or back

Squamous cell carcinoma:

• A firm, reddish, wart-like bump that grows gradually
• A flat spot with a scaly crusted surface that won't heal
• Make an appointment with your doctor if you notice any abnormal skin changes, particularly if you experience changes in the appearance of an existing mole, or you have a new skin growth or sore that doesn’t heal.

Skin cancer is the most common form of cancer. It is the abnormal growth of skin cells and most often develops on skin exposed to the sun, however can also occur on areas of your skin not ordinarily exposed to the sunlight.

What types of skin cancer are there?

There are 3 major types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma.

• Basal cell carcinoma: Basal cell carcinomas are by far the most common type of skin cancer. They usually develop on sun-exposed areas, especially the face, neck and head. Basal cell carcinomas are detected easily and are usually curable. These cancers tend to grow slowly, and rarely spread beyond the skin. However, if a basal cell cancer is left untreated, it can grow into nearby areas and invade the bone or other tissues beneath the skin. After treatment, basal cell carcinoma can recur in the same place on the skin. People who have had basal cell cancers are also more likely to get new ones elsewhere on the skin.
• Squamous cell carcinoma: Squamous cell carcinomas are somewhat more aggressive and more inclined to spread than basal cell cancers. These cancers commonly appear on sun-exposed areas of the body such as the face, ears, neck, lips, and backs of the hands. Squamous cell carcinomas tend to grow and spread more than basal cell cancers. They are more likely to invade fatty tissues just beneath the skin, and are more likely to spread to lymph nodes and/or distant parts of the body, although this is still uncommon.
• Melanoma: Melanoma, although rarer, is much more deadly. Melanoma can start in heavily pigmented tissue, such as a mole or birthmark, as well as in normally pigmented skin. Melanoma most commonly appears first on extremities, such as the chest or back, although it can occasionally arise on the palm of the hand, sole of the foot, under a fingernail or toenail, in the mucus linings of the mouth, vagina, or anus, and even in the eye. Although melanoma can be treated if it is detected early enough, it progresses faster than other types of skin cancer and can spread beyond the skin to affect numerous parts of the body, including the bones or brain. Once this occurs, melanoma becomes very dangerous and difficult to treat. It accounts for the majority of skin cancer deaths.

Who is at highest risk of getting skin cancer?

The risk of skin cancer is much higher for people with light-coloured skin, compared with dark-skinned people. This is due to the protective effect of the skin pigment melanin in people with darker skin. White people with fair skin that freckles or burns easily are at especially high risk. This is one of the reasons for the high skin cancer rate in Australia, where there is intense sunshine and much of the population descends from fair-skinned immigrants from the British Isles. In fact, the Australian Institute of Health and Welfare estimates that two in three Australians will be diagnosed with skin cancer before the age of 70. People with a family history of skin cancer are also at greater risk. In addition, old age increases the risk of developing skin cancer.

What causes skin cancer?

Although skin cancer can run in families, the Skin Cancer Foundation claims that most cases of skin cancer develop because of damage caused by ultraviolet (UV) radiation from the sun, which in turn damages the genetic material inside skin cells. Like the sun, tanning booths also emit damaging UV radiation. Cells may then begin to multiply and grow out of control. Basal cell carcinoma and squamous cell carcinoma have been linked to chronic sun exposure, typically in fair-skinned people who spend considerable time outside. Melanoma is associated with infrequent but excessive sun exposure that causes scorching sunburns. 

Most skin cancers display symptoms early on. If your doctor suspects skin cancer, he or she will use certain medical tests to determine the cause of the problem. These include:

• Physical exam of your skin: Your doctor may look at your skin to determine whether your skin changes are likely to be cancer. During the physical exam, the doctor will note the size, shape, color, and texture of any areas in question, and whether there is bleeding or scaling. The rest of your body may be checked for spots and moles that could be related to skin cancer. Further testing may be needed to confirm a diagnosis.
• Skin biopsy: If your doctor thinks that a suspicious area might be skin cancer, he or she will take a sample of skin from the area for laboratory testing. This procedure is called a skin biopsy. A biopsy can determine whether you have skin cancer and, if so, what type of skin cancer you have. If the biopsy removes the entire tumor, it is often enough to cure basal and squamous cell skin cancers without further treatment. Skin biopsies are done using a local anesthetic, which is injected into the area with a very small needle. You will probably feel a small prick and a little stinging, but you should not feel any pain during the biopsy.

After skin cancer has been diagnosed, tests are often done to find out if cancer cells have spread within the skin or to other parts of the body. Imaging tests, including positron emission tomography (PET scan) ;computed tomography (CT scan), or magnetic resonance imaging (MRI), may be used to identify metastases (cancer spread) in other parts of the body, such as the lungs, brain, liver, or other organs. This helps to inform treatment options.

Different treatment options are recommended for skin cancer and precancerous skin lesions known as actinic keratoses, depending on the size, type, depth and location of the lesions. For small skin cancers limited to the surface of the skin, treatment beyond an initial skin biopsy that removes the entire growth may not be needed. However, if additional treatment is needed, options may include:

• Cryosurgery: Your doctor may destroy actinic keratoses and some small, early skin cancers by freezing them with liquid nitrogen. There is no cutting or bleeding, and no anesthesia is required with this procedure. The growth becomes crusted and scabbed, and usually falls off within weeks. 
• Excisional surgery: This type of treatment may be appropriate for any type of skin cancer. Your doctor cuts out the cancerous tissue, along with a surrounding border of apparently normal skin as a safety margin. The wound around the surgical site is then closed with stitches.
• Laser therapy: A precise, intense beam of light vaporises growths, generally causing little damage to surrounding tissue. This therapy may be used to treat superficial skin cancers.
• Mohs surgery: This procedure is for larger, recurring or difficult-to-treat skin cancers. The doctor removes the skin growth layer by layer, examining each layer under the microscope, until no abnormal cells remain. This procedure allows cancerous cells to be removed and saves the greatest amount of surrounding healthy tissue.
• Curettage and electrodesiccation: After removing most of a growth, your doctor scrapes away layers of cancer cells using a circular blade. An electric needle destroys any remaining cancer cells. This simple, quick procedure may be used to treat small or thin basal cell cancers or squamous cell cancers. However, it is not considered as effective for more invasive, aggressive squamous cell carcinomas or those in high-risk or difficult sites, such as the eyelids, genitalia, lips and ears.
• Radiation therapy: X-ray beams are directed at the tumor, with no need for cutting or anesthesia.  This technique can involve long-term cosmetic problems and radiation risks, as well as multiple visits. For these reasons, this therapy is mainly used for tumors that are hard to treat surgically, as well as patients for whom surgery is not advised, such as the elderly or those in poor health.
• Chemotherapy: In chemotherapy, drugs are used to kill cancer cells. For cancers limited to the top layer of skin, creams or lotions containing anti-cancer agents may be applied directly to the skin. Systemic chemotherapy can be used to treat skin cancers that have spread to other parts of the body.
• Photodynamic therapy (PDT): This treatment destroys skin cancer cells with a combination of laser light and drugs that makes cancer cells sensitive to light. PDT can be especially useful for growths on the face and scalp.

Most skin cancers are preventable. Below are some guidelines to help protect you from skin cancer:

• Seek the shade: Avoid being outdoors in direct sunlight for too long. This is particularly important between the hours of 10 am and 4 pm, when UV light is strongest. 
• Apply sunscreen: Apply 1 ounce (2 tablespoons) of sunscreen to your entire body 30 minutes before going outside. Reapply every 2 hours or immediately after swimming or excessive sweating.
• Use a broad spectrum (UVA/UVB) sunscreen every day: The sunscreen should have an SPF of 15 or higher. For extended outdoor activity, use a water-resistant, broad spectrum (UVA/UVB) sunscreen with an SPF of 30 or higher.
• Cover up: When you are out in the sun, use clothing to protect as much skin as possible. Include a broad-brimmed hat and UV-blocking sunglasses.
• Avoid UV tanning booths: Tanning beds emit UV rays and can raise your risk of skin cancer. Tanning bed use has been linked with an increased risk of melanoma, especially if it is started before the age of 30.
• Be aware of sun-sensitising medications: Some common prescription and over-the-counter drugs, including antibiotics, can make your skin more sensitive to sunlight. Mayo Clinic recommends asking your doctor or pharmacist about the side effects of any medications you take.
• Protect children from the sun: Children need special attention, since they tend to spend more time outdoors, can burn more easily and may not be aware of the dangers. Babies younger than 6 months should be kept out of direct sunlight and protected from the sun using hats and protective clothing. Sunscreens should be used on babies over the age of six months.
• Have regular checkups: See your physician every year for a professional skin exam.