How to spot skin cancer: Symptoms, treatment and protection
Skin cancer rates are rising, possibly due to global heating. Here's how to spot a melanoma and stay safe in the sun.
Depending where you live in the world, skin cancer is the most common type of cancer. Melanoma of the skin is particularly common across northern and southern parts of Europe, North America and Australia. There are two main types of skin cancer, non-melanoma skin cancer and malignant melanoma, and rates of both types are on the rise. The World Health Organization (WHO) Global Cancer Observatory predicts global increases in skin cancer between 2020-2040. (Also read: Warning signs your body pain is associated with cancer)
Is global heating increasing skin cancer rates?
It's difficult to say for sure what is causing rising skin cancer rates, but researchers suggest that rising global temperatures are at least partly to blame.
In October 2021, an editorial in the Lancet science journal said "ultraviolet radiation because of climate change is thought to be associated with the rising incidence of skin cancer and melanoma."
And a review of evidence published by Elsevier and the Women's Dermatological Society in 2020 said there was "strong circumstantial evidence [that] supports the hypothesis that factors related to climate change have likely contributed to the increasing incidence of cutaneous malignancy globally and will continue to impose a negative influence on skin cancer incidence for many decades to come."
Demographics and skin color make a difference
People with pale skin, blue eyes and red or fair hair are at greater risk of skin cancer. People of color — or as the WHO puts it "naturally brown or Black people" — "can usually safely tolerate relatively high levels of sun exposure without getting sunburnt or greatly increasing their skin cancer risk."
Some of the highest rates of skin cancer are reported in Australia and New Zealand. This is often attributed to the fact that the two countries have large white populations with ancestry linked to European settlers. As most of those early settlers had fair skin, they were unaccustomed to the harsh sun.
Skin cancers remain relatively rare in Africa and Asia. But there are data from the Global Cancer Observatory that suggest African countries could see a 96% increase in new cases by 2040 compared to 2022. Asia could see an increase of 59% and Latin America and the Caribbean 67% in that same period.
What are the main risk factors for skin cancer?
Skin cancer is more common in older people, but young people are also at risk. Sometimes, the underlying damage to the skin is done in early age, or you may have a family history of skin cancer.
Bear in mind these other factors as well:
Do you burn easily in the sun?
Do you have many moles and/or freckles?
Do you have a history of severe sunburns?
Too much exposure to solar UV, ultraviolet light radiation from the sun, is just about the greatest risk factor, which means that if you live near the equator or indeed south of the equator, you face a higher risk of skin cancer.
There are eight major sub-groups of skin cancer
Cancer Research UK highlights the following eight types of melanoma, starting with the most common types:
Superficial spreading melanoma is the most common type of melanoma. It affects men and women aged between 30 and 50 years. In men, it is often found on the central part of the body and among women, on the legs.
Nodular melanoma is the second most common type of melanoma, found on any part of the body.
Lentigo maligna melanoma is found on the face and other parts of the body that are exposed to the sun — it is common among people who spend a lot of time outdoors.
Rarer types of melanoma include:
Amelanotic melanoma, which can be overlooked, as these melanomas lack color.
Acral lentiginous melanoma is found on the palms of the hands and soles of the feet.
Mucosal melanoma starts in mucous membranes, such as in the anus, vagina, penis, vulva, mouth and digestive system.
Melanoma of the eye develops in the uvea, the middle layer of the eye.
And desmoplastic melanoma, which is found on the head and neck.
How do you spot skin cancer?
The US Centers for Disease Control and Prevention says there is "a simple way to remember the warning signs" — the A-B-C-D-Es of melanoma:
Asymmetrical: Does the mole or spot have an irregular shape with two parts that look very different?
Border: Is the border irregular or jagged?
Color: Is the color uneven?
Diameter: Is the mole or spot larger than the size of a pea?
Evolving: Has the mole or spot changed during the past few weeks or months?
By checking your skin regularly, you can catch early signs of skin cancer. If you are concerned about any changes, please seek professional advice from a healthcare provider. Experts recommend you get screened for skin cancer at least every other year.
How to protect yourself again skin cancer
To stay safe in the sun, we yield to Australian authorities, who have their own simple strategy: Slip, Slop, Slap, Seek, Slide.
Slip on sun-protective clothing
Slop on broad spectrum, water resistant SPF30 sunscreen
Slap on a hat with a broad brim to protect your face, head, neck and ears
Slide on some sunglasses
Look good, by all means, but make sure your sunglasses and accessories do the job of protecting you from the sun. Good sun-protection gear should carry labels that declare the level of UV-protection they offer. And cover your arms and legs with clothing as best you can. It might be uncomfortable in the heat, but it'll be better for your skin in the long-run.
Edited by: Carla Bleiker