What are the main types of skin cancer?
Have you noticed small, soft, flesh-coloured growths hanging off your skin? These common skin growths, known medically as acrochordons, are usually harmless and don’t pose any health risk. But they can be a nuisance and affect a person’s self-esteem especially if they are in visible areas of the body.
Melanoma
Melanoma develops in melanocytes – the type of cells that give colour to our skin, hair, and eyes. Although it is less common than non-melanoma forms, it is the most aggressive and life-threatening type of skin cancer due to its ability to spread easily. According to Melanoma New Zealand, around 4,000 New Zealanders are diagnosed with melanoma every year, making it the third most common cancer in the country. Every year Melanoma kills over 350 Kiwis, and is responsible for approximately 80% of skin cancer-related deaths. Cure rates for melanoma depend on the cancer’s stage at the time of detection, which means regular mole mapping and skin assessments are crucial for safe-guarding your health.
Non-Melanoma Type Skin Cancers
(Squamous Cell Carcinomas and Basal Cell Carcinomas)
According to the UK National Health Service (NHS), the first signs of non-melanoma skin cancer are usually a discoloured patch of skin or a lump, lesion or ulcer on the skin that gradually changes appearance. There are a few slight differences in their development:
- Basal Cell Carcinomas are the most common form of skin cancer, and tend to start as small and shiny pink or white lumps that look waxy, or a small scaly red patch on your skin. As they progress, little bits of black or brown may appear on the lesion, and a lump starts to grow. It may bleed, crust or ulcerate, but is often painless.
- Squamous Cell Carcinomas are the second most common form of skin cancer, and usually first appear as a pink, crusty lump. As they progress, scaly skin develops around the lump and it becomes painful. They often bleed and might start to ulcerate.
How to detect and prevent skin cancer
Where does skin cancer develop?
All forms of skin cancer develop more frequently in areas of the body that receive more UV radiation. The most commonly sun-exposed areas, and thus the most likely to be the location of cancerous moles and lesions, include:
- Face
- Neck
- Ears
- Shoulders
- Upper chest
- Back
- Hands
However this does not mean that these are the only areas you should take care to protect from the sun, or check during a skin examination. Skin cancers can develop anywhere on the body, and forgetting to check hard to see areas can lead to skin cancer going undetected for a dangerous amount of time. So ask a loved one to help you check difficult to see areas like your back, and don’t forget less obvious places like the sole of your feet, or your privates.
Does skin cancer affect people of colour?
Although people with fair skin are significantly more at risk, people with darker skin should also take care to perform regular skin checks as any ethnicity can develop skin cancer. Here in New Zealand, statistics show that Māori, Asian, Pasifika, and other peoples of colour may have a lower risk of getting skin cancers, but they are often diagnosed when the cancer is at a more serious stage. Therefore it is crucial not to fall into a false sense of security if you have a darker skin type and do not burn easily– sun safety and regular skin assessments could still save your life!
How to perform a skin exam on yourself
Although unfortunately there is no one way to immediately tell the difference between a normal mole or lesion and a cancerous one, there are tools which can help you such as the acronym ABCDEFG.
How can an acronym help us determine if our skin is safe? Well, the letters ABCDEFG refer to several common warning signs which can tell us whether a mole or lesion might need treatment.
The ABCDEFG system tells us to watch out for:
Asymmetry: When one half is a different shape to the other.
Border irregularity: unclear, jagged or uneven edges.
Colour change: Multiple, uneven, changing colours and/or an irregular colour.
Difference: Any mole or lesion that stands out from the rest.
Evolving features: Changes in pain, texture, size, or starting to bleed.
Firmness: Firm to the touch
Growth: Growing size, especially if rapid and 6mm or larger.
Another skin assessment tool is the ‘Ugly Duckling’ rule. The Ugly Duckling rule reminds you to look out for anything out of the ordinary when examining your skin. If you notice any skin lesions or moles that stand out as very different to anything else on your body, it might be an ‘Ugly Duckling’ worth taking for a trip to the skin specialists for closer inspection!
How are the early stages of skin cancer diagnosed?
In the early stages, a visual diagnosis of skin cancer can often be made and treatment taken by simply excising the suspicious mole or lesion – aka it will be cut out of the skin.
In other situations, a biopsy might be taken and sent to a lab for a pathologist to examine and give a diagnosis. Blood tests, X-rays, and CT, PET, and MRI scans can also be used to gain a better understanding of how far, if at all, the cancer has spread. These additional steps usually only apply to melanoma, as non-melanoma cancers only spread in rare cases.
According to the UK National Health Service (NHS), the first signs of non-melanoma skin cancer are usually a discoloured patch of skin or a lump, lesion or ulcer on the skin that gradually changes appearance.
How are the early stages of skin cancer staged?
Once a diagnosis is made, skin cancer can be staged. This depends on a few factors, including thickness, and how far the cancer has spread.
Here in New Zealand, most skin specialists use a framework from the American Joint Committee of Cancer (AJCC) when diagnosing the stage of a melanoma.
The stages are:
Stage 0 – In situ. It only occurs in the skin’s top layer.
Stage 1 – Thin. It is 2mm or smaller in thickness, or less than or equal to 1mm if there is ulceration.
Stage 2 – Thick. It is greater than 2mm in thickness, or 1mm if there is ulceration.
Stage 3 – It has spread to local lymph nodes.
Stage 4 – It has spread and secondary cancers are found elsewhere in the body.
But what about non-melanoma skin cancers?
As these forms of cancer are far less likely to spread, they often do not require staging, especially basal cell cancers. If you are diagnosed with squamous cell skin cancer, and you have not sought treatment for a long time, it may be staged as this form of non-melanoma skin cancer can spread to other parts of the body, although it is rare.
When should I seek help from a medical professional or dermoscopist?
We recommend that you should seek help from a medical professional like a GP or a skin specialist such as a dermoscopist as soon as you notice any new, unusual, or changing skin lesions or moles. By receiving medical advice and a professional skin check as soon as you notice anything out of the ordinary on your skin, you give yourself the best chance of cancer being diagnosed at the earliest stage. Early detection can be a life-saver, especially when it comes to melanoma.
How NZ Skin Health can help
If you see anything new, changing or unusual on your skin, book an appointment with NZ Skin Health’s highly-trained and compassionate skin specialists.
Call us on 09 533 41 41 or
to book a skin assessment today.