Around 90% of melanoma skin cancers are caused by excessive exposure to the sun (UVR). All people living in New Zealander are exposed to higher levels of ultraviolet radiation (UVR) and are at risk of being diagnosed with skin cancer. During the summer months these UV rays are highest. Artificial sources of UV light (sunlamps or tanning beds) can also increase your risk of skin cancer.

There are two groups of skin cancers. Non-melanoma skin cancer, and melanoma skin cancer.

Non-melanoma skin cancer: are a group of skin cancers, and make up the vast majority of skin cancer diagnosis. They develop slowly in the upper layers of your skin and tend to be less serious when treated. The two most common types of non-melanoma skin cancers are basal cell carcinoma and squamous cell carcinoma.

Basal Cell Carcinoma (BCC): is the most common and least serious form of skin cancer – as long as it is treated. They often appear as change in your skin in areas exposed to the sun. Such as a small bump, sore, or scaly red flat mark. They can be pearly white, pink, or skin coloured. They may bleed or develop into an ulcer and will not heal.

See DermNet NZ for images of BCC

Squamous Cell Carcinoma (SCC): typically appear as raised, scaly, crusty, non-healing lesion. They are common in people over 40 years of age who have had prolonged exposure to UVR. They will often appear on areas of the body that have been exposed to the sun over many years. If left untreated SCC can be deadly. 

See DermNet NZ for images of SCC

Melanoma is less common than non-melanoma skin cancers like BCC and SCC. However, it is the most aggressive form of skin cancer. It is caused by overexposure to UVR, this is why New Zealand has one of the highest rates of melanoma in the world.

Melanoma can appear as a new spot or mole, existing mole that changes, appear raised. If left untreated it can spread rapidly to other parts of your body. They most often occur on parts of your body that have been exposed to excessive sun causing sunburn but can be found anywhere on the body. To help you identify potential melanomas use the ABCDE warning signs.

A: Asymmetry of shape (i.e., the two halves don’t match)

B: Border irregularity, including blurred, smudged or ill-defined margin

C: Colour variation and change (brown, tan, black, red, or white)

D: Different (appears to be unique amongst other moles)

E: Evolving (enlarging, changing over months or years)

Early detection and intervention will almost always result in successful treatment.

See DermNet NZ for images of melanoma.

There is a risk of developing skin cancer for people of all ages, and skin colours in New Zealand. However, there are risk factors which may increase an individual’s likelihood of developing skin cancer:

• Light coloured (pale or fair) skin that burns easily,
• a history of moderate to severe sunburn,
• spending a lot of time outdoors,
• people who sunbath or tan using sunbeds or UV lamps,
• people with a family history of skin cancer,
• people with 10 or more atypical moles*.

*Atypical Moles are moles with irregular shape and colour.

Atypical moles (dysplastic nevus) are very common and benign (not cancerous). However, people who have many atypical moles are at more risk of melanoma.  People who have 10 or more atypical moles are 12 times more likely to develop melanoma.

Atypical moles may be caused by a mix of genetics and exposure to UVR. They may have some or all the following features:

• Irregular or asymmetrical shape,
• blurred or rough edges,
• varied colours/shades of brown, tan, black, or red,
• 5mm or larger

These moles have many of the same features as melanomas and can be difficult to distinguish. Therefore, it is important to see a dermatologist when in doubt.

Between September and April UV radiation levels are very high in New Zealand. As over 90% of skin cancer cases are caused by excess UVR exposure protecting your skin and avoiding sunburn throughout your life will greatly reduce your risk.

SunSmart

Slip on clothing that covers as much skin as possible.

Slip into the shade of a leafy tree, building or shade sail. Plan your outdoor activities for early or later in the day when the sun’s UV levels are lower.

Slop on sunscreen, look for broad-spectrum, water-resistant sunscreen of at least SPF 30. Apply 20 minutes before going outside and reapply every two hours, or after being in water or sweating.

Slap on a hat with a wide brim or with flaps covering the ears and neck.

Wrap on sunglasses. Not all sunglasses protect against UV radiation, so always check the label for the sun protection rating.

Learn More About SunSmart

It is important to check your skin for any moles, or irregularities that have appeared or changed over time. Remember skin cancer can appear in places that are hard to see or may not get regularly exposed to the sun. Ideally you should get a professional skin check every 12 months, as melanoma is very difficult to detect. If you notice any changes or new moles it is always best to see your dermatologist as soon as possible – if in doubt, get checked.