Causes of Skin Cancer

Most skin cancer is caused by ultraviolet (UV) light, the main source being sunlight, damaging the DNA in skin cells. Sunlight contains three types of UV light; ultraviolet A (UVA), ultraviolet B (UVB) and ultraviolet C (UVC). Ultraviolet C is most dangerous to the skin but it gets filtered out by the Earth’s atmosphere. UVA and UVB damage pale skin over time, making it more likely for skin cancers to develop. Ultraviolet B is thought to be the main cause of skin cancer overall, but it is not yet known UVA also plays a role in causing melanoma. Tanning beds also increase your risk of developing skin cancer in people of all ages.
There are three major types of skin cancer basal cell carcinoma, malignant melanoma and squamous cell carcinoma.

Basal cell carcinoma

Abnormal, uncontrolled growths come from the skin’s basal cells in the outermost layer of the skin. This type of cancer occurs on skin areas that are typically exposed to the sun, especially the face, ears, neck, scalp, shoulders and back. Most BCCs are caused by the combination of intermittent, intense exposure and cumulative, long-term exposure to UV radiation from the sun.

These factors increase your BCC risk:

● UV exposure from the sun or indoor tanning.
● Family history of skin cancer, including squamous cell carcinoma or melanoma.
● Older than 50: Mostly appears in people over the age of 50.
● Fair skin: People with fair skin have an increased risk.
● Being male: Men are more likely to develop BCC.
● Chronic infections and skin inflammation from burns, scars and other conditions.

Malignant melanoma

Melanoma is cancer that develops from melanocytes (the skin cells that produce melanin pigment) which gives skin its colour. It is the most dangerous of the three most common forms of skin cancer, however, it can be curable when caught and treated early. Melanomas often resemble moles and sometimes may arise from them. They can be found on any area of the
body, even in areas that are not typically exposed to the sun. It is often triggered by the kind of intense, intermittent sun exposure that leads to sunburn. Tanning beds can also increase the risk for melanoma.

These factors increase your melanoma risk:

● Unprotected or excessive UV exposure from the sun or superficial tanning.
● A weak immune system due to a medical condition or medications.
● The more moles you have on your body, the higher your risk for malignant melanoma. Having large moles or any moles increases your risk.
● Melanoma occurs more frequently in people with fair skin or anyone with less melanin.
● People who have a history of having had melanoma or nonmelanoma skin cancers run a greater risk of developing melanoma in the future.
● Melanoma can run in a family – one in every 10 patients has a family member who has had the disease.

Squamous cell carcinoma

Squamous cell carcinoma (SCC) is an uncontrolled growth of abnormal cells arising from the squamous cells in the outmost layer of skin (epidermis). Where is it usually found? SCCs are common on sun-exposed areas such as the ears, face, scalp, neck and hands, where the skin often reveals signs of sun damage, including wrinkles and age spots. Cumulative, long-term exposure to UV radiation from the sun and tanning beds causes most SCCs.

These factors increase your SCC risk:

● Unprotected exposure to ultraviolet (UV) radiation from the sun or tanning beds.
● Weakened immune system due to illness or certain immunosuppressive medications.
● History of skin cancer including basal cell carcinoma (BCC).
● Age over 50: Most SCCs appear in people over age 50.
● Fair skin: People with fair skin are at an increased risk for SCC.
● Gender: Men are more likely to develop SCC.
● Sun-sensitive conditions include xeroderma pigmentosum.
● Chronic infections and skin inflammation from burns, scars and other conditions.
● Skin precancers include actinic keratosis.
● History of human papillomavirus (HPV)

Moles
You have an increased risk of melanoma if you have lots of moles on your body, particularly if they’re large (more than 5mm) or unusually shaped. For this reason, it’s important to monitor your moles for changes and avoid exposing them to intense sun.

Other risk factors you’re also more likely to develop melanoma skin cancer if you have:

● A close relative who’s had melanoma skin cancer
● Pale skin that does not tan easily
● Red or blonde hair
● Blue eyes
● Several freckles
● Previously damaged your skin through sunburn or radiotherapy treatment
● A condition that suppresses your immune system, such as diabetes or you take medicines that suppress your immune system (immunosuppressants)
● A previous diagnosis of skin cancer
● The risk of developing skin cancer also increases with age.

Symptoms of Skin Cancer
Skin cancers aren’t all identical, and they may not cause many symptoms. Still, unusual changes to your skin can be a warning sign for the different types of cancer. Being alert for changes to your skin may help you get a diagnosis earlier.

Watch out for symptoms, including:

Skin lesions: A new mole, unusual growth, bump, sore, scaly patch, or dark spot develops and doesn’t go away.
Asymmetry: The two halves of the lesion or mole aren’t even or identical.
Border: The lesions have ragged, uneven edges.
Colour: The spot has an unusual colour, such as white, pink, black, blue, or red.
Diameter: The spot is larger than one-quarter inch, or about the size of a pencil eraser.
Evolving: You can detect that the mole is changing size, colour, or shape.

Talk to your doctor if you notice changes in your skin such as a new growth, a sore that doesn’t heal, a change in an old-growth, or any of the A-B-C-D-Es of melanoma.

Prevention and Screening

Prevention
Follow these tips to protect your skin from the sun’s damaging ultraviolet rays and reduce your risk of skin cancer:

Seek shade when appropriate, remembering that the sun’s rays are strongest between 10 a.m. and 2 p.m. If your shadow is shorter than you are, seek shade.

Wear sun-protective clothing, such as a lightweight and long-sleeved shirt, pants, a wide-brimmed hat and sunglasses with UV protection, when possible. For more effective sun protection, select clothing with an ultraviolet protection factor (UPF) label.

Apply a broad-spectrum, water-resistant sunscreen with an SPF of 30 or higher. Broad-spectrum sunscreen protects from both UVA and UVB rays.

Use sunscreen whenever you are going to be outside, even on cloudy days. Apply enough sunscreen to cover all skin not covered by clothing. Most adults need about 1 ounce — or enough to fill a shot glass — to fully cover their bodies. Don’t forget to apply to the tops of your feet, your neck, your ears and the top of your head. When outdoors, reapply sunscreen every two hours, or after swimming or sweating.

Use extra caution near water, snow, and sand, as they reflect the damaging rays of the sun, which can increase your chance of sunburn.

Avoid tanning beds. Ultraviolet light from tanning beds can cause skin cancer and premature skin ageing.

Consider using a self-tanning product if you want to look tan, but continue to use sunscreen with it.

Perform regular skin self-exams to detect skin cancer early, when it’s most treatable, and see a board-certified dermatologist if you notice new or suspicious spots on your skin, or anything changing, itching or bleeding.

A tan is a sign that your skin has been injured. Whether you’re exposed to the sun’s UV rays or visit an indoor tanning salon, every time you tan, your skin is damaged. As this damage builds, you speed up the ageing of your skin and increase your risk for all types of skin cancer, including melanoma, the deadliest form of skin cancer.

Screening
If you think a mole or other skin lesion has turned into skin cancer, your primary care provider will probably refer you to a dermatologist. The dermatologist will examine any moles in question and, in many cases, the entire skin surface. Any lesions that are difficult to identify, or are thought to be skin cancer, may then be checked.

Tests for skin cancer may include:

The doctor may use a handheld device called a dermatoscope to scan the lesion. Another handheld device, MelaFind, scans the lesion then a computer program evaluates images of the lesion to indicate if it’s cancerous.
A sample of skin (biopsy) will be taken so that the suspicious area of skin can be examined under a microscope.
A biopsy is done in the dermatologist’s office.
If a biopsy shows that you have malignant melanoma, you may undergo further testing to determine the extent of the spread of the disease, if any. This may involve blood tests, a chest X-ray, and other tests as needed. This is only needed if the melanoma is of a certain size.