What is Skin Cancer?
Skin cancer is a common and possibly life-threatening disease that often suffers from a myriad of misconceptions. In order to understand what skin cancer is, and what it means for Australians, it is important to put this disease in perspective through some facts and statistics. According to the Cancer Council, there are over 400,000 people diagnosed every year with a non-melanoma type of skin cancer and over 13,000 with melanoma in Australia. This makes skin cancer the most common form of cancer in the country, with two in three Australians diagnosed with variant types of skin cancer in their lifetimes.
Around 2000 Australians die from skin cancer every year, approximately 1,300 from melanoma skin cancer and 700 from nonmelanoma skin cancers. Australia, alongside New Zealand, has the highest rates of skin cancers in the world. Australia has a two to three times greater occurrence of skin cancer than other English speaking countries like the United States or the United Kingdom. Therefore, sun protection is very important to protect the skin from possible damage. This means that living in Australia puts you at a higher risk of skin cancer development over your lifetime and encourages a greater need for sun protection.
According to the Australian Cancer Council, skin cancer is mainly caused by exposure to UV radiation, which is emitted by the sun. Before tanning salons were banned in Australia, some people also received unhealthy dosages of UV radiation from tanning beds. If you are fair-skinned, have light eyes and hair, or have a family history of skin cancer, you will have to pay special attention to preventative measures to protect yourself from the sun. However, all Australians should safeguard themselves, as skin cancer is the most commonly diagnosed type of cancer in Australia.
The main types of skin cancer separate into melanoma or non melanoma skin cancer. For a non melanoma form of skin cancer, the most commonly diagnosed are squamous cell carcinoma (SCC) or basal cell carcinoma (BCC). We will explain more about these skin cells below and how to best identify skin cancers of these kinds.
UV stands for ultraviolet, and it describes light emitted by the sun that we cannot see. Unlike infrared radiation, which is also outside of the visible spectrum but is felt as heat, UV radiation cannot be felt in any way. That’s why you can get a sunburn even on a cold or cloudy day without directly being exposed to sunlight. Occupational exposure to the sun is a prevalent cause of skin cancer and causes up to 34,000 cases a year in Australia. While people will often come prepared to protect themselves at the beach or at a barbecue, people often overlook the need to do so while at work.
Occupational skin cancer is a common cause of the disease worldwide, particularly in jobs that involve heavy sun exposure such as construction work, sport, or traffic control. UV radiation can damage your DNA, which can deactivate important safeguards in your cells that keep them from growing uncontrollably (and skin cancer is basically the uncontrolled growth of damaged abnormal cells). Usually, your body would make sure to get rid of skin cells that have been damaged, but with tumours, these cells can proliferate and, if left untreated, eventually spread through your body and attack other organs, too.
Your skin is the largest organ of your body, and it is also one of the most complicated. It not only holds everything inside our body together but also plays an important role in providing a flexible, airtight, and watertight barrier between the outside world and the bodily systems on the inside of our bodies. Our skin plays many different roles in our overall health, such as helping to control body temperature, helping in immune defence, vitamin production, and giving us touch sensation-and yet it also has many potential problems, with more than 3,000 possible skin disorders and various concerns for skin cancers. The skin is very unique in lots of ways, but no other organ demands so much attention and concern in both states of disease and health. So, what exactly is our skin meant to do and how does it impact our life?
There is more than one layer of skin
The skin is divided into three layers known as the epidermis, dermis, and subcutis. Each layer of skin is well defined but together they allow the skin to function effectively.
The epidermis is the outermost, cellular layer of the skin which varies in thickness depending on the area of the body. In most cases, it’s under half a millimetre thick. The epidermis is somewhat similar to a “brick wall” of cells (keratinocytes) which are connected together tightly and act to block the free movement of moisture, pathogens, and chemicals into or out of the body. On the top surface of the epidermis is where squamous cells are found, and the very bottom layer of the epidermis – basal cells. These are two cell types that commonly develop skin cancer. Keratinocytes replicate from the basal cells layer and work their way up to the outer surface (known as the stratum corneum) over a period of about 28 days. Once they reach the surface the tight bonds between them break apart and they are shed. Other than keratinocytes, pigment-producing cells known as melanocytes and immune cells known as Langerhans cells also exist within the epidermis. Melanocytes inhabit the basement membrane, at the base of the epidermis and produce a pigment known as melanin both innately (giving the skin its natural colour), and in response to ultraviolet light (UV) exposure (giving the skin a suntan). The melanin is a brown pigment that is taken up into the overlying keratinocytes. This pigment will then absorb UV light (from the sun) when it hits the skin, thereby protecting the basal cells underneath from UV damage.
The dermis lies beneath the epidermis and is 20-30 times thicker. It’s made up of a dense layer of fibrous (collagen) and elastic (elastin) tissue. The dermis gives the skin its integrity, strength and elasticity; and houses blood vessels, glands and hair follicles, as well as nerves and their receptors.
Beneath the dermis lies the subcutis (also known as the hypodermis), a specialised layer of fatty tissue known as adipose (fat) and fibrous tissue.
The functions of the skin
The skin performs an array of different functions for the body, including:
- Works as a barrier
- Helps our immune system to fight off bugs, allergens, toxins, and carcinogens.
- Regulates our temperature
- Protects us from UV radiation
- Gives us the sense of touch
- The production of Vitamin D, which helps to prevent many diseases
- Wound healing
Different Types of Cell Cancers
The three main types of skin cancer (basal cell carcinomas, squamous cell carcinomas, and melanomas) can be located in very different areas. While the first two are usually found in areas frequently exposed to the sun, melanomas can also develop on such rarely exposed areas as your back or the inside of your legs. That’s why it’s extra important to take the time to check those areas for skin cancers too. Of the three main types of skin cancer, the first two- basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are commonly known as keratinocyte cancers as they both form in the cells known as keratinocytes. Keratinocyte cancers are known as non-melanoma skin cancer.
Basal Cell Carcinoma
The most common type of skin cancer, basal cell carcinoma (BCC) is often caused by frequent sun exposure. It generally occurs on regions of the body that endure the highest levels of exposure (head and neck, face, shoulder, to name a few) and especially affects people with fair skin, light hair, and lighter-coloured eyes. A shiny, reddish, dry area of skin may indicate the presence of basal cell carcinoma (BCC) developing from these flat cells. Other signs of BCC Basal cell carcinoma can include a small lump, an open sore, or a growth with an elevated border. Basal cell carcinoma (BCC) is often completely asymptomatic.
Squamous Cell Carcinoma
Accounting for roughly 30% of non-melanoma skin cancers, squamous cell carcinoma (SCC) begins in the upper layer of the epidermis. It, too, is often found in chronic sun-exposed areas like the head and neck and is more likely to occur in people with fairer complexions. However, squamous cell carcinoma (SCC) can also occur where there are pre-existing burns or other inflammatory conditions. These skin cancers tend to grow from abnormal cells quite quickly and symptoms of their presence include rapidly growing skin lesions like a lump, scaly red spots, open sores, and tenderness when touched.
Melanoma skin cancer is also most likely to occur on parts of the body that have endured overexposure to the sun. However, it may also be found in parts of the body that are rarely or never exposed to the sun. For women, melanomas most frequently occur on the legs, though for men, they are most often found on the back. Though melanoma may not have any obvious symptoms, initial signs common to melanoma skin cancer include the appearance of a new spot or a change in the appearance of an existing mole. This could involve an increase in the mole’s size, a change in colour or colours, or a shift in the mole’s shape and elevation. One major risk of this type of cancer is that it can spread to other parts of the body. If you are diagnosed with melanoma and it has spread to other parts of the body, some of the symptoms include hardened lumps under your skin, swollen or painful lymph nodes, trouble breathing, or a cough that doesn’t go away, swelling of your liver (under your lower right ribs) or loss of appetite, as well as bone pain or, less often, broken bones. It is very important that you see a doctor as soon as possible if you think you are at risk of skin cancer cells that have spread to other parts of your body or your lymph nodes. Besides these three main types, there is also another form of skin cancer known as Merkel cell carcinoma. This form of skin cancer is a rare type of skin cancer that usually appears as a flesh-coloured or bluish-red nodule, often on your face, head, or neck. Merkel cell carcinoma is also called neuroendocrine carcinoma of the skin. Merkel cell carcinoma most often develops in older people.
The earliest forms of skin cancer include basal or squamous cell carcinoma in situ (stage 0). When looking for skin cancer cells in the early stages, you should look for any spots that are irregular in colour, size, or shape, any new spots, or any that have recently changed. Cell carcinoma in situ is a group of abnormal cells that are found only in the place where they first formed in the body. For basal cell carcinoma (BCC) or squamous cell carcinoma (SCC) this will appear on the surface of your skin that is most often exposed to direct sunlight, but for melanoma skin cancers they could appear anywhere on your body. You will need to also check for changes to your skin in parts of your body that are hard to see such as the back, neck, and scalp. Some people even use two mirrors to gain better visibility. If too difficult, it is advised to book an appointment with a doctor at a skin cancer treatment clinic for a full check. If you think that you have detected skin cancers on your body, check other parts of the body to see if there are any other spots of concern. After you’ve identified a spot that you believe is skin cancer you should get to a doctor as soon as you can. However, while you are waiting for your appointment or the doctor to open it might be a good idea to check the rest of your body for any warning signs of melanoma skin cancer or nonmelanoma skin cancer (BCC or SCC), or carcinoma in situ. The Cancer Council recommends using the ABCDE method for help in diagnosing suspicious moles or spots. ABCDE stands for:
- A – Asymmetry, irregularity
- B – Border (uneven)
- C – Colour
- D – Diameter (usually, but not always more than 6mm)
- E – Evolving (changing and growing)
Common Myths or Misconceptions about Skin Cancer
Skin cancer is the most common form of cancer in Australia, with two in three people diagnosed in their lifetime. With over 2000 people a year dying from skin cancer in the country, it is vital to know fact from fiction. Here are five common myths about skin cancer that need to be debunked:
People need to be outdoors regularly and for long periods of time to get skin cancer
This is one of the most prevalent myths that prevent people from taking proper precautions against sun damage throughout their day. Skin damage is a cumulative effect, it doesn’t need to present itself as bad sunburns and raw skin, it can be caused by brief moments of sun exposure over years of walking to work, watching TV next to an unfiltered window, or sitting in an outdoor cafe. These moments can add up and eventually form skin cancer. To protect yourself you should always take proper precautions when exposed to the sun for any period of time, particularly between the peak UV hours of 10am and 4pm.
People with darker skin are not at risk of developing skin cancer
This is dangerously wrong. While it is true that darker-skinned people have a lower risk of developing skin cancer and being diagnosed with melanoma, there is still the possibility that it happens. Because of the myth that darker people don’t get skin cancer they often undergo fewer checks and often detect skin cancer only when it is at a more developed, and more dangerous stage.
You don’t need to protect yourself from the sun on a cloudy day or during winter
Ultraviolet (UV) radiation is the primary cause of skin cancer. This radiation is constantly projected by the sun and can be strong or weak despite the temperature of the day. These rays can penetrate clouds and be just as strong on a cool autumn day as a warm summer one. In winter, particularly if people are skiing or on vacation in the mountains, the snow can reflect UV rays and significantly increase the amount of UV radiation you are exposed to, increasing your risk of skin cancers.
Young people don’t get skin cancer
This is false. While less common than in older people it is still a serious issue with skin cancer identified as the leading form of cancer in young adults and teenagers. It is also important to keep in mind that severe sunburn early in life can dramatically increase your chance of skin cancer when you are older.
People need to spend prolonged periods of time in the sun to increase their Vitamin D levels
Vitamin D is important for an individual’s health and wellbeing and can be produced in the body through exposure to the sun. However, short bursts of sun, outside the peak hours of 9am to 4pm is more than enough to produce the Vitamin D that your body needs. If in doubt you can also buy Vitamin D supplements, rather than risk overexposure to UV Rays.
The best prevention, according to the Australian Cancer Council, is protecting your skin and avoiding intense UV radiation as much as possible. Just remember to “Slip, Slop, Slap”! Slip-on some protective clothing, slop on at least 35 ml of sunscreen, and slap on a hat. But there’s also “Seek and Slide” – seek some shade and slide on sunglasses to protect your eyes as well. Our experts at SunDoctor further recommend avoiding the sun altogether between 11 am and 3 pm – in Australia, the level of UV radiation will almost always be harmful in those hours. Make sure that the hat you choose has a wide brim or other features that reliably cover your neck and ears. For your protective clothing, it’s best to wear something with long sleeves and a collar – remember, UV radiation can be high on cold days, too. The good news is that all of these measures, together with early detection schemes, have reduced the mortality rates for all types of skin cancer, even aggressive melanoma types.
Find the Right SPF for Skin Protection
SPF stands for Sun Protection Factor, and it is a relative measure of the duration that a particular sunscreen will protect you from ultraviolet B (UVB) rays. UVB rays are the main cause of sunburn and the main culprit for common types of skin cancer. This shouldn’t be confused with UVA rays which are longer and more likely to penetrate deeper into the body and cause internal damage to DNA cells and signs of aging. However, SPF is based on UVB rays, which vary in intensity throughout the day.
On a particularly hot day, a person might burn after 10 minutes of sun exposure. If they were using a sunscreen with SPF 15 on the packaging then they would burn after 150 minutes, or 15 times longer than they would without any sunscreen. Similarly, if they were using SPF 30, they would burn after 300 minutes, or 30 times longer than without sunscreen. It is important to understand that this is a relative measure, which means that it is based on how long an individual would take to burn without sunscreen. This is dependent on the person’s skin type, where they live, the intensity of the UV index on that day, and other factors. So it is not easy to calculate how long you can stay out in the sun before burning, only that SPF 30 sunscreen will protect you for twice as long as SPF 15.
With most SPF products only referring to protection from UVB rays, you need to find a sunscreen with a broad spectrum SPF protection to minimise your risk of being diagnosed with melanoma or non-melanoma skin cancer in your lifetime. A broad range SPF protects you from both UVA and UVB rays giving you the highest protection from melanoma and non-melanoma skin cancer.
If you develop skin cancer that is left untreated, it can spread from where it originated to other parts of the body. When skin cells that are cancerous break away from a tumour, they can then travel to other areas of the body via the bloodstream or the lymphatic system. Cancer cells that travel through the lymphatic system may end up in lymph nodes. Most of these escaped cancer cells are killed off or die before they can start to grow somewhere else, but one or two cells might settle in a new area and begin to form new tumours. The spread of cancer that happens this way in the body is called metastasis. If you experience painful and swollen lymph nodes and are at risk of skin cancers having spread throughout your body, it is vital that you see a doctor at a cancer treatment centre as soon as possible.