Melanoma explained

Malig­nant melanoma is the most seri­ous type of skin can­cer. Over the last decade, global annual rates of melanoma have risen by almost 50% to more than 287,000 cases.

Melanoma starts in the melanocytes. These cells are found in the out­er lay­er of the skin (at the base of the epidermis). Their job is to make melanin — the pig­ment that gives your skin its nat­ur­al colour. Ultraviolet (UV) exposure causes the melanocytes to produce melanin. This results in darker or ‘tanned’ skin.

Over-exposure to UV radiation, typically from the sun, damages the DNA in the melanocytes. This causes the melanocytes to multiply uncontrollably, leading to melanoma. What makes melanoma most dangerous is its ability to quickly spread to other organs. While melanoma makes up a small proportion of skin cancer diagnoses (around 3%), it accounts for 65% of all deaths from skin cancer. This risk is particularly significant for outdoor workers, who receive 5-10 times more UV exposure than indoor workers.

FACT: Just 20-30% of melanomas are found in existing moles. Most (70-80%) appear as a new growth.

Over-exposure to UV radiation is the major risk factor for melanoma and other types of skin cancer. Excessive sun exposure during adulthood and childhood has been found to increase an individual’s melanoma risk. Other risk factors include:

• Having numerous moles
• A family/personal history of melanoma
• Increasing age
• Fair skin that burns easily
• Light/red hair and blue or green eyes
• Occupational UV exposure

Take our quick risk assessment to find out your personal skin cancer risk.

The relationship between workplace UV exposure and melanoma risk has become increasingly clear through extensive research. New Zealand workers in outdoor industries face some of the highest occupational UV exposure levels globally, primarily due to our geographical location and climate. This exposure occurs during peak working hours when UV levels are at their highest, creating a perfect storm for potential skin damage.

The impact of outdoor work

Construction workers, farmers and other outdoor professionals face unique challenges in managing melanoma risk. These workers often experience both direct and reflected UV radiation, with some surfaces like metal, concrete and water increasing UV exposure by up to 40%. Recent studies indicate that outdoor workers develop melanoma at nearly twice the rate of indoor workers, highlighting the critical importance of sun protection for outdoor workers.

The construction industry, in particular, has seen concerning trends. Workers frequently operate on elevated platforms or scaffolding, where UV exposure intensifies with height. Additionally, the physical nature of the work often leads to reduced compliance with protective clothing requirements, especially during warmer months when the risk is highest.

Indoor workers: understanding the hidden risks

While indoor workers generally face lower UV exposure, the risks shouldn't be underestimated. Modern office environments, with large windows and open layouts, can create unexpected UV exposure patterns. Standard window glass blocks most UVB rays but allows up to 75% of UVA rays to penetrate, potentially contributing to skin damage over time.

Many indoor workers also face what dermatologists call "weekend warrior" syndrome – limited sun exposure during the week followed by intense weekend outdoor activities. This pattern of intermittent exposure has been linked to increased melanoma risk, particularly for those who work indoors but engage in outdoor recreational activities without proper sun protection.

Sun protection at work falls under Work Health and Safety (WHS) legislation, which requires employers to protect workers from UV radiation risks. This goes beyond simply providing sunscreen – employers should implement sun safety programs that address all aspects of UV exposure risk. Whether you're working on a construction site, in agricultural fields, or near office windows, understanding and actively managing your UV exposure can significantly reduce your melanoma risk.

Effective strategies for sun protection at work

Successful workplace sun protection requires a multi-faceted approach. Engineering controls, such as shade structures and UV-protective screens, should be the first line of defence. These should be complemented by administrative controls, including flexible work hours that minimise exposure during peak UV periods and regular rotation of workers between indoor and outdoor tasks.

Personal protective equipment is crucial but must be appropriate for the specific work environment. High-visibility clothing with UV protection, broad-brimmed hard hats with neck flaps, and UV-protective eyewear should be standard issues for providing sun protection for outdoor workers. Sunscreen should be available, and workers should be trained in its proper application and reapplication.

Regular skin checks become particularly important for those with occupational UV exposure. Many workplaces now partner with skin cancer clinics to provide regular screening services for their workers. These programs have proven effective in early melanoma detection, particularly among high-risk outdoor workers.

Melanoma can occur anywhere on the body. Often it grows in places you might not expect, such as areas rarely exposed to the sun. It can develop in an existing mole or freckle. More commonly though, melanoma appears as a new spot. 

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The different types of melanoma can appear in various shapes, sizes, and colours. This can make it difficult to detect. Knowing the ABCDE-EFG rules of melanoma can help you to spot the warning signs.

• A — asymmetrical
• B — borders are uneven
• C — colour change
• D — diameter is large
• E — evolving in size
• E — elevated
• F — firm
• G — growing

Essentially, if you notice a new or changing mole or a mole becomes sore or looks abnormal, have it checked out by scheduling a mole check at skin cancer clinics. Early detection and prompt evaluation are crucial in effectively managing potential skin cancer concerns.

Superficial spreading melanoma is the most common form of melanoma. It may look like a flat or partly raised patch of skin. It tends to be asymmetrical with uneven borders. It can be different colours, from various shades of black to brown. It may even be pinky-red, white, or bluish in colour. The truth is, melanoma can look different from person to person.

For a better understanding of the signs, looking at pictures of skin cancer can be useful. Take a look at this gallery of melanoma pictures from the Skin Cancer Foundation, as a helpful guide.

One Australian is diagnosed with melanoma every 30 minutes. On a positive note—if found early, more than 90% of melanomas can be successfully treated through surgery. Most melanomas are diagnosed with a skin examination (i.e., a skin check). If your medical practitioner suspects melanoma, they will do a biopsy. This is where a small tissue sample is taken and reviewed under a microscope.

Skin examination

This involves a thorough skin examination to spot atypical and potentially cancerous moles or lesions.

Excision biopsy

If a lesion or mole is believed to be melanoma, it pays to remove the entire abnormal area for testing. The most common procedure for this is called an excisional biopsy. The entire mole and a small margin of healthy tissue around it are removed. It’s a straightforward process that can be done by a GP, dermatologist, or a surgeon under local anaesthetic.

Melanoma treatment depends on the stage of the cancer. This is determined by the thickness (vertical depth) of the tumour. Treatment options for melanoma include:

• Surgery — removal of the melanoma and surrounding tissue
• Radiation therapy — uses x-rays to destroy the cancer cells and stop them from multiplying
• Immunotherapy — medications that support the body’s immune system to attack the cancer
• Targeted therapy — medication to fight the cell mutations that cause the cancer to grow and spread

Melanoma is most effectively treated when it is in its early stages. Several factors that may affect treatment outcome. This includes the type and stage of cancer, the individual’s age, and health status at the time of diagnosis.

According to the Melanoma Institute Australia, 95% of melanomas are caused by over-exposure to UV light. Protecting your skin against the sun’s UV rays is the single biggest thing you can do to reduce your melanoma risk. 

Practice sun safety

It’s important to wear SPF 50+ sunscreen with broad-spectrum UVA and UVB protection. Avoid the sun during the hottest part of the day. Wear protective clothing. And don’t forget to pop on a hat and sunglasses to keep your head and eyes safe. 

Get a skin check

Both melanoma and non-melanoma skin cancers can be effectively treated when diagnosed early. The best way to do this is with regular professional skin examinations, as well as at-home skin checks. Don’t forget, melanoma doesn’t always appear in the most obvious spots. Find out more about the places you might forget to check for skin cancer.

Skin checks

Regular (annually or as directed by your GP or skin specialist) skin checks are essential to skin cancer prevention and early detection. Knowing your skin is the best way to spot new or changed moles.