More information
What is skin cancer?
Skin cancer develops when the skin cells see an abnormal spurt of growth, with DNA damage (usually caused by UV light/sun) causes genetic defects. The cells replicate with this DNA damage, perpetuating the problem and causing a cancerous growth.
There are three major categories of skin cancer:
- Basal cell carcinoma
- Squamous cell carcinoma
- Melanoma
- Keratinocyte dysplasias (solar keratosis, Bowenoid keratosis and squamous cell carcinoma in-situ (Bowen’s disease))
Basal cell and squamous cell carcinomas are known as non-melanoma cancers, and are the most common skin cancers in Australia, though they do not pose a great risk of death like melanomas do. Over 750,000 Australians will be treated for non-melanoma skin cancers every year, but the survival rate is very good. Early detection is key.
Basal cell carcinoma (BCC) skin cancer
BCC cancers are the majority of non-melanomas (about 70 per cent), with BCC appearing on the topmost outer layer of skin (the epidermis). BCC skin cancers appear almost anywhere on the body but are most common in areas of high sun exposure like the head, neck, face, shoulders and back.
There are usually no symptoms and BCCs are slow to grow. You might see a pearl-like lump or a shiny, scaly area that is pink or pale in colour.
Squamous cell carcinoma (SCC) skin cancer
SCC make up about a third of all skin cancers in Australia that are not melanomas, and SCC occur in the upper layer of the epidermis, typically in sun-exposed areas (head, neck, arms, legs). Compared to the BCC, SCC is fast-growing over weeks or months.
Symptoms of an SCC are a thick, scaly area, a fast-growing lump, the appearance of a sore that won’t heal, and/or tenderness of this area.
Cause of non-melanoma skin cancers
The cause of all skin cancers it generally the same: UV-damaged ‘dud’ skin cells replicating themselves. You have a greater propensity to develop skin cancer if you have a lot of moles, have fair skin that burns easily, lots of freckles, light eye colour, light/red hair, and if you have had previous skin cancer.
Any visible changes should be reported to your dermatologist, along with getting regular checks.
Melanoma skin cancers
Melanomas are a serious form of skin cancer whereby melanocytes – the pigment-producing cells in your skin – overgrow.
Melanocytes are found in the outer layers, and their job is to produce melanin – the dark pigment that causes tanning and dark skin tones. The variation in human skin tone we see is due to differing levels of production of melanin, despite everyone having the same amount of melanocytes – the darkest and the lightest skin are all equal in melanocytes – but those melanocytes in dark complexions produce a lot more melanin than those with light.
Albinos lack properly-functioning melanocytes, leaving them without melanin – pigment – at all.
Melanin is protective because it absorbs UV light, thus preventing it from entering our bodies further, causing deeper cell damage. Dark-skinned people are much less likely to be UV-damaged than those with lighter complexions.
Growths of melanocytes can be non-cancerous, and appear as the very common mole or as freckles. Cancerous growths of melanocytes is a melanoma.
Melanomas are classified by how far they have spread, for example ‘in situ’ means just on the skin, ‘invasive’ means the tumour has spread into other layers of skin, and ‘metastatic’ means cancer has spread to other tissue.
Who gets melanoma?
The highest rates of melanomas in the world are found in Australia and New Zealand, with a rate of about one in every 15 New Zealanders and 7.5 in every 15 Australians developing a melanoma in their lifetime. Men are affected more than women, though this is thought to be due to women being better informed about skin-cancer prevention than men.
Melanoma usually affects adults only and is rare in children. Those in the 45 – 65 age bracket are the most likely to be diagnosed.
What does melanoma look like?
A melanoma may appear from within an already-existing freckle or mole, or may appear on otherwise normal-looking skin as a new growth. Three-quarters of the time a melanoma appears from normal-looking skin. A melanoma from within a mole or freckle is characterised by changes in shape, size, and texture – typically a freckle will become odd-looking or misshapen.
Melanomas may be tan, black, dark brown, blue, red, or grey. A melanoma without pigment can also occur, and the skin may appear scarred, normal, or white.
Melanomas have different growth phases, with the first horizontal phase appearing flat. Once the vertical phase commences, melanoma thickens and rises.
Where are skin cancers most likely to appear?
Cancers can appear anywhere on the body, including areas that never see the light of day. The most common site is the back in men and legs in women.
The lips, eyes, brain and genitals aren’t very good growth areas for melanoma cancers, but from time to time this does occur.
Preventing and detecting skin cancer early
You need to get regular skin checks from your health professional or a trusted ‘mole-spotting’ partner who is trained in proper examination. You can get a buddy and do mole checks on each other regularly.
After skin cancer is detected and removed, checks should be conducted six-monthly for five years, but this drops down to ever four months for more advanced disease. Skin cancers can develop quickly, so catching it early is key.
New treatments being developed for treating malignant skin cancers
There are trials going on all the time for new treatments. These include:
- Interferons – some promising results, though side-effects can be intolerable
- Ipilimumab – promising results for metastatic melanoma
- BRAF inhibitors – vemurafenib (Zelboraf) – trametinib (Mekinist), dabrafenib (Tafinlar), and pembrolizumab (Keytruda)
- Talimogene laherparepvec (Imlygic) – genetically-modified live herpes simplex virus that is designed to replicate within tumours causing an immune reaction
- Tumour-cell vaccines
Contact us to make an appointment today with one of our skin cancer specialist dermatologists.
*Results may vary from person to person
Skin cancer FAQ