Applying sunscreen all year-round, regardless of the weather, and not just when out in the sun (also apply sunscreen when indoors) is a way of lowering risk of skin cancer.
Excessive exposure to sunlight is the main cause of skin cancer, the sixth most common cancer amongst men and women in Singapore.
Skin cancer develops when skin cells undergo genetic mutations, leading to abnormal and uncontrolled growth.
The primary cause is ultraviolet (UV) radiation from the sun or artificial sources like tanning beds, which damages DNA in skin cells over time. This damage disrupts normal cell function, allowing mutated cells to multiply unchecked.
In some cases, genetic factors or exposure to harmful substances can also contribute to these mutations, triggering cancerous changes.
The good news is that most types of skin cancer are highly curable if detected early. Skin cancer is also highly preventable.
Limiting sun exposure is the most effective precaution you can take.
Types of skin cancer
There are three main types of skin cancer. These are:
- Non-melanoma skin cancer (NMSC) – Non-melanoma skin cancer refers to all the types of skin cancer that are not melanoma, such as basal cell carcinoma and squamous cell carcinoma. Non-melanoma skin cancer slowly develops in the upper layers of the skin.
In Singapore, non-melanoma skin cancer is much more common than melanoma skin cancer. Non-melanoma skin cancer is the 6th most common cancer in males in Singapore and the 7th most common cancer among females in Singapore.
- Melanoma – Least common but most dangerous
- Rare skin cancers
a) Merkel cell carcinoma – This is a rare and aggressive type of skin cancer which can affect older adults with lighter skin pigmentation.
b) Kaposi’s sarcoma can occur in different forms and it is often associated with immunosuppression.
c) Skin lymphomas
“Melanomas are rare amongst Asians compared to Caucasians with fairer skin. In Singapore, the incidence of melanoma is nine times less than BCC,” shares the Department of Dermatology from Singapore General Hospital (SGH), a member of the SingHealth group.
“This is fortunate because melanomas are amongst the deadliest cancers, accounting for 75 per cent of all skin cancer deaths.”
Other less common types of skin cancer include Kaposi’s sarcoma, Merkel cell carcinoma, and sebaceous gland carcinoma.
How to prevent skin cancer
Most skin cancers are preventable. There are several ways to lower the risk of skin cancer:
- Avoid sun exposure during the middle of the day (10am-4pm).
- Excessive exposure to ultraviolet (UV) rays in sunlight increases the risk of developing skin cancer. Avoiding the sun at its strongest helps to avoid the sunburns and suntans that cause skin damage and increase the risk of developing skin cancer.
- Sun exposure accumulated over time may also cause skin cancer.
- Excessive exposure to ultraviolet (UV) rays in sunlight increases the risk of developing skin cancer. Avoiding the sun at its strongest helps to avoid the sunburns and suntans that cause skin damage and increase the risk of developing skin cancer.
- Apply sunscreen all year-round, including when indoors, on cloudy days or overseas in cold weather
- Sunscreen should be used every day, and works best when it is applied 15 minutes before going outdoors. It should be reapplied every two hours or more frequently, especially when engaging in water sports or sweating a lot.
- Use a broad spectrum sunscreen that protects against both UVA and UVB, the Sun Protection Factor (SPF) of the sunscreen should be at least SPF 30 or higher. While higher-number SPFs can block slightly more of the sun’s UV rays, it is important to note that higher-number SPFs do not give longer protection and must be re-applied as frequently as sunscreens with lower SPF.
- Apply a generous amount of sunscreen on exposed skin, including the lips, the tips of your ears, and the backs of your hands and neck.
- Sunscreen should be used every day, and works best when it is applied 15 minutes before going outdoors. It should be reapplied every two hours or more frequently, especially when engaging in water sports or sweating a lot.
- Wear sun-protective clothing
- As sunscreens do not provide complete protection from UV rays, it is important to cover your skin with dark, tightly woven clothing that covers your arms and legs, and a broad-brimmed hat, which provides more protection than a baseball cap or visor does.
- Use sunglasses that block both types of UV radiation — UVA and UVB rays.
- Avoid tanning beds as the lights used in tanning beds emit UV rays that can increase the risk of skin cancer.
- Ask your doctor or pharmacist about the side effects of any medications you take. If they increase your sensitivity to sunlight, take extra precautions to stay out of the sun to protect your skin.
- Examine your skin often for new skin growths or changes in existing moles, freckles, bumps and birthmarks. Make an appointment with your doctor if you notice any changes that worry you.
Risk factors for skin cancer
While excessive exposure to the sun is the main cause of skin cancer, there are many factors that can increase your risk of getting this disease. These factors include:
- Excessive sun exposure
- Tanning, including exposure to tanning lamps and beds
- Moles – having many moles or abnormal/atypical moles
- Fair skin – having less pigment (melanin) in the skin provides less protection from UV rays and causes the skin to burn easily
- Family or personal history of skin cancers
- A weakened immune system (due to a medical condition or medicine that affects the immune system)
- Sunny or high-altitude climates
- Pre-cancerous skin lesions (actinic keratosis)
- Exposure to radiation and substances such as arsenic
“Fair-skinned people have less of the pigment melanin which protects against ultraviolet radiation, which is why they are at higher risk. But that doesn’t mean dark-skinned people can’t get skin cancer,” says the SGH Department of Dermatology.
Diagnosis of skin cancer
Tests and procedures used to diagnose skin cancer include:
- A physical examination using a dermatoscope to determine whether the skin changes are likely to be skin cancer.
- A skin biopsy is a minor procedure usually done under local anaesthetic (where you are conscious) where a tissue sample of the suspicious skin growth is taken and sent to the lab for testing and analysis.
In some cases, skin cancer can be diagnosed and treated at the same time. The tumour is removed and tested and you may not need further treatment if the cancer is unlikely to spread.
In other cases, once skin cancer is confirmed, further tests may be needed to determine the extent (stage) of the cancer and the most suitable treatment. The tests may include:
- Blood test
Blood tests are done to determine baseline organ function.
- Imaging tests
Imaging in the form of CT scan or PET CT scan are done to determine the extent of the disease and distant spread.
- Lymph node biopsy
A lymph node biopsy involves the removal of a small amount of lymph node tissue for laboratory testing to check for signs of cancer.
Skin cancer treatment
In general, treatment for skin cancer depends on the following factors:
- Size, type, depth and location of the lesion
- Stage of the disease when the cancer is found
- The patient’s general state of health
The main treatment for skin cancer is surgery. However, some patients may also require other treatments such as chemotherapy, radiotherapy, or cryotherapy.
Type of treatment |
What it does |
|---|---|
Surgery |
|
Curettage and electrocautery |
The tumour is scraped off the healthy skin and the area is heated to destroy remaining cancer cells. |
Freezing (Cryotherapy) |
The cancer cells are frozen off with liquid nitrogen. |
Radiotherapy / Radiation therapy |
Radiotherapy also known as radiation therapy uses powerful energy beams to kill cancer cells. It may be used when the cancer cannot be completely removed during surgery. |
Systemic therapy |
For skin cancers confined to the top layers of the skin, topical treatments such as creams or lotions containing anti-cancer agents may be applied directly to the affected area. However, when the cancer is more advanced or has spread beyond the skin, systemic therapy may be needed. Systemic therapy refers to treatments that circulate throughout the body to target cancer cells wherever they may be. This includes:
For the rest of the body, chemotherapy (injected into a vein or taken orally) can be used to treat skin cancers that have spread to other parts of the body. In patients with advanced skin cancer, chemotherapy may be used alone or with surgery, immunotherapy and radiotherapy. |
Photodynamic therapy |
This is a new form of treatment that combines oxygen, light energy and a photosensitizer to generate oxygen radicals that eliminate cancer cells. |
If the skin cancer spreads to other parts of the body, a combination of excision surgery, radiation and chemotherapy or immunotherapy may be used to treat it.
“Early detection and timely treatment of skin cancer can cure most non-melanoma skin cancers. However, the prognosis for thick melanoma with widespread metastasis is grave,” explains the SGH Department of Dermatology.
How to recognise a melanoma
This ABCDE rule can help you distinguish a melanoma growth from a benign mole. According to this rule, the five signs of melanoma are:
A = Asymmetry – the growth is uneven in shape
B = Border – the border or edges are irregular
C = Colour – haphazard combination of many colours
D = Diameter – over 6 mm
E = Evolving – enlarging/changing shape of a pigmented growth
All skin cancer patients require regular follow-up after treatment to check for recurrence or spread of the cancer to other parts of the body.
It is important to seek medical advice if you notice any suspicious-looking growth or a change in an existing growth on your skin.
Ref: G25 (ed)
Related article:
Does a higher SPF sunscreen mean better protection than a lower one? Not necessarily. Click here to find out why.
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