What is Skin Cancer and what are the types of Skin Cancer in Singapore?
Skin cancer is the abnormal growth of skin cells that occurs most frequently in skin exposed to and damaged by the sun.
The epidermis consists mainly of these three types of cells:
- Basal Cells – These produce new skin cells
- Squamous Cells – These are the skin’s inner lining
- Melanocytes – These produce melanin pigment
Therefore, there are 3 main types of skin cancer:
- Basal Cell Carcinoma - Basal cells are the skin cells that produce new skin when the old ones die. Basal cell carcinoma usually appears as a slightly transparent bump on the skin, but can take other forms as well. It usually occurs in areas most exposed to the sun, like the head and neck regions. It is thought to be caused by long-term exposure to ultraviolet (UV) rays by the sun.
- Squamous Cell Carcinoma - Squamous cells are thin, flat cells that make up the outermost layer of the skin. They continuously shed as new skin cells form. This is usually not life-threatening but can be aggressive. Open sores may appear anywhere on the body, including inside the mouth, on the soles of the feet and on your genitals.
- Melanoma - This is the most severe form of skin cancer. The melanocytes which are pigment cells that produce the pigment melanin are affected. Melanomas can develop on any part of the body and often develop in areas that are exposed to sunlight, such as the face, arms, back and legs.
The first signs of melanoma are:
- Changes in an existing mole
- The development of a new pigmented or unusual-looking dark growth on the skin that is asymmetrical with an irregular border
What causes Skin Cancer?
Skin cancer occurs when the genes in the skin cells become mutated due to exposure to UV light. These mutations cause the skin cell replication cycle to go haywire, forming a mass of cancer cells.
Skin cancer begins in the skin’s outermost layer or the epidermis.
Common symptoms of Skin Cancer in Singapore?
Signs and symptoms of skin cancer include:
- A large brown spot with darker speckles
- A mole that changed size, colour, texture or bleeds
- A small lesion with an irregular shape and portions that appear red, pink, white, blue or blue-black
- A lesion that is painful, itchy or burns
- Dark lesions on your palms, soles, fingertips, toes, or mucous membranes lining your mouth, nose, vagina or anus.
What are the risk factors for Skin Cancer?
There are some risk factors that make you more prone to skin cancer, which include:
- Fair Skin - Anyone can get skin cancer, but those with less melanin, the dark pigment found in your skin and eyes, may be at higher risk of skin cancer. This melanin pigment not only gives your skin a darker colour, but it also protects you from the sun’s UV rays which can cause damage to your skin and lead to skin cancer.
- Easily Sunburnt - Those who have a history of being sunburnt easily are more likely to develop skin cancer.
- Long-term Exposure to Sunlight - Those who spend long hours under the sun, be it for work or leisurely activities like suntanning, are at higher risk of skin cancer. This is especially so for those who do not use sunscreen or do not have protective clothing. Tanning under tanning lamps also puts you at the same risk due to UV radiation.
- Sunny or High-Altitude Climates - Those who live in sunny or high-altitude climates are more likely to be exposed to sunlight than those who live in colder climates. High altitudes mean the sunlight is stronger too.
- Moles - People who have moles are more likely to get skin cancer simply because these moles are more likely to turn into cancerous growths. If you have many moles or any abnormal moles, keep a look out for any signs of changes to their shape, colour and texture.
- Precancerous Skin Lesions - Skin lesions may increase your risk of getting skin cancer. The precancerous skin lesions are rough and scaly patches that range in colour from brown to pink. They commonly appear on the face, head and hands, especially on those with fair skin and sun damage.
- Family History of Skin Cancer - If your parents or siblings have had skin cancer, you are also more likely to develop it.
- Personal History of Skin Cancer - If you have had skin cancer before, you’re more likely to have it again.
- Weakened Immunity - Those with weakened immune systems, because they have HIV or are taking immunosuppressants, are at greater risk of developing skin cancer.
- Exposure to Radiation - Radiation treatment for those with skin conditions like eczema and acne may cause you to be more prone to skin cancer.
- Exposure to Certain Substances - Exposure to chemicals like arsenic may cause you to develop skin cancer.
What are the treatment options available for Skin Cancer in Singapore?
Small skin cancers may be frozen with liquid nitrogen in cryosurgery. The tissues die off and the dead tissues slough off when they thaw.
This is when cancer cells are excised or cut out through surgery, along with some margin of surrounding healthy tissue. A wider excision that may remove more normal skin around the tumour is sometimes necessary.
This procedure is designed for those with larger or recurring skin cancers that are tougher to treat, which may include basal and squamous cell carcinomas. It is often used in areas where more skin needs to be conserved, such as on the nose.During Mohs surgery, your surgeon removes the cancerous growth layer by layer until no abnormal cells remain, allowing cancerous cells to be removed without disturbing too much of the normal skin around it.
Curettage and Electrodesiccation or Cryotherapy
After removing most of the cancerous growth, the remaining cancer cells may be scraped away using a curet which is a circular blade. An electric needle then destroys the remaining cancer cells. A variation of this procedure uses liquid nitrogen to freeze the base and edges of the remnant cancer cells.
Radiation therapy uses high-energy radiative waves like X-rays to kill cancer cells. This is an option when surgery is unable to entirely remove the cancerous growth.
In chemotherapy, drugs are used to kill cancer cells. Systemic chemotherapy may be used for skin cancers that have spread to other parts of the body.For cancers that are on the outer layers of the skin, creams or lotions with anti-cancer agents may be topically applied onto the skin.
This uses drugs that make cancer cells sensitive to light, then destroys these cancer cells with laser light.
This uses the body’s own immune system to target the cancer cells. Chemicals may be injected to stimulate your immune cells to kill the cancer cells. Alternatively, some immune cells may be taken from your body and trained in a lab to attack cancer cells before reintroduction into your body.Cancer cells can sometimes send signals that suppress the immune system. In this case, we can use drugs called immune checkpoint inhibitors to block the signals coming from the cancer cells. This then makes them more susceptible to immune responses that were originally turned off.
There are many types of biological therapy, most of which are still under clinical trials. Speak with your doctor to see if this type of therapy is available or may suit you.
How do I prevent Skin Cancer?
There are some lifestyle changes you can make to prevent yourself from getting skin cancer, such as:
Avoiding mid-day sun
The sun’s rays are strongest from 10 a.m. to 4 p.m., so if you really need to go out, try to pick a time outside of that.
Wearing sunscreen when you go out
Applying broad-spectrum sunscreen of SPF 30 and above on all the exposed areas of your skin may help to protect you from strong UV radiation.
Wearing protective clothing
Covering your skin with dark clothing that cover your arms and legs, or using a cap or a hat would work well in protecting your skin from sun damage. Photo-protective clothing is also recommended. Sunglasses may help to block both UVA and UVB.
Avoiding tanning beds
Tanning beds use UV rays which can increase the risk of skin cancer.
Reducing the usage of sun-sensitising medication
Some over-the-counter or prescription drugs like antibiotics may make your skin more sensitive to the sun. Find out about the side effects of your medication from your doctor if you take any. If you need to take sun-sensitising medication, be sure to wear sunscreen when going outdoors or avoid the sun altogether to protect yourself.
Checking your skin regularly
Regularly examine your skin for any changes such as growths or patches of discolouration. Check your moles, freckles, bumps and birthmarks for signs of abnormalities.