Skin cancer, a prevalent and potentially dangerous condition, can develop on areas of the skin exposed to the sun, as well as on those typically shielded from sunlight. It starts in the skin's epidermis, the outermost layer crucial for body protection and skin cell renewal.

In Singapore, between 2017 and 2021, non-melanoma skin cancer was the sixth most common type of cancer among males, with 2,136 cases, and the seventh among females, with 1,713 cases, according to the Singapore Cancer Registry Annual Report 2021, underscoring the importance of awareness and early detection across both genders.

What is the Main Cause of Skin Cancer?

Skin cancer arises from both controllable lifestyle factors and immutable genetic predispositions.

Some of the common causes include:

• Ultraviolet (UV) Radiation: The primary culprit behind most skin cancers is overexposure to UV radiation. UV rays can damage the DNA in skin cells, leading to mutations that increase cancer risk. This is especially relevant in Singapore, where the UV index frequently reaches very high and even extreme levels, particularly between 11am and 3pm on sunny days. In fact, in March 2024, the UV index hit extreme levels, highlighting the importance of sun protection, as chronic exposure to these intense UV rays can potentially lead to melanoma and other types of skin cancer.
• Exposure to Harmful Substances: Regular contact with toxic chemicals such as pesticides or tar can elevate the risk of developing skin cancer.
• Occupational Hazards: Jobs that involve exposure to ionising radiation, like radiology, also heighten the risk.
• Genetic Factors:
  • Family History: Those with a familial history of skin cancer are inherently more susceptible.
  • Ethnicity and Skin Type: While fair-skinned individuals are at a higher risk. In Singapore, non-melanoma skin cancer ranks as a leading cancer among Chinese males and females, illustrating significant ethnic and demographic trends in its occurrence. However, skin cancer does not discriminate completely by skin tone; it can affect those with darker skin, albeit differently.
• Actinic Keratoses: These scaly patches may progress to squamous cell carcinoma if left untreated.
• Immunosuppression: Long-term use of immunosuppressive drugs post-organ transplant increases vulnerability to skin cancer.
• Photosensitivity: Some medical conditions and medications enhance skin sensitivity to UV rays, compounding the risk.

Skin Cancer Risk Factors

Several factors increase the risk of developing skin cancer, regardless of age. These include a family or personal history of skin cancer, fair or freckled skin, skin that burns easily, a history of sunburn or tanning bed use, outdoor occupations or lifestyles, and a high number of moles or irregular lesions.

While skin cancer can occur at any age, the risk tends to increase as individuals grow older, with most cases appearing after the age of fifty. For instance, in Singapore, the incidence of non-melanoma skin cancer in males rises significantly with age, escalating from 49 cases in the 30 to 39 age group to 295 cases among those aged 50 to 59, and further peaking at 481 cases in the 60 to 69 age bracket, according to the Singapore Cancer Registry Annual Report 2021.

Types Of Skin Cancer

Understanding the various types of skin cancer is essential for early detection and successful treatment.

The three major types are basal cell carcinoma, squamous cell carcinoma, and melanoma.

1. Basal Cell Carcinoma

Basal cell carcinoma is a common type of skin cancer that originates in the basal cells, responsible for producing new skin cells. Typically appearing as a slightly transparent bump, basal cell carcinoma often occurs on sun-exposed areas such as the head and neck. Prolonged exposure to UV radiation from sunlight is considered a primary cause, making sun protection vital in preventing this type of skin cancer.

Symptoms of this kind of skin cancer include:

• Pearly or waxy bumps
• Flat scar-like lesions
• Recurring bleeding or scabbing sores

2. Melanoma

 

Melanoma is the most serious type of skin cancer that develops in the cells responsible for producing melanin, the pigment that gives colour to the skin. While UV radiation exposure is a significant risk factor with research showing that 86% of such cancer cases are due to overexposure to UV radiation, melanoma can also occur in areas of the body not exposed to the sun. Early detection is crucial for successful treatment, as melanoma can spread rapidly.

Be vigilant for symptoms such as:

• Notable brown patches interspersed with darker dots
• Moles that undergo changes in hue, dimensions, or texture
• Small growths with uneven edges showcasing a mix of colours such as red, pale pink, white, blue, or deep black
• Lesions that are sore and prone to itching
• Unusual dark markings on less exposed areas like the palms, underfoot, or the inner linings of the mouth, nasal passages, or other mucosal areas

3. Nonmelanoma Skin Cancer

Nonmelanoma skin cancer encompasses various types of skin cancer, excluding melanoma. The most common types include basal cell carcinoma and squamous cell carcinoma. Treatment for nonmelanoma skin cancer typically involves surgical removal of the cancer cells.

4. Squamous Cell Carcinoma Of The Skin

Squamous cell carcinoma of the skin arises in the squamous cells of the middle and outer layers of the skin. While usually not life-threatening, untreated squamous cell carcinoma can lead to complications and even spread to other parts of the body. Prolonged UV radiation exposure is the primary cause, emphasising the importance of sun protection.

Keep an eye out for symptoms such as:

• Firm, red nodules
• Flat lesions with a scaly, crusted surface.

What Rare Skin Cancer is Worse than Melanoma?

While melanoma is widely recognised for its severity, other rare skin cancers also pose significant risks and can be more challenging to treat.

Merkel cell carcinoma (MCC), for instance, originates from neuroendocrine cells near the skin's nerve endings. This type of cancer is not only aggressive but can also manifest as ulcers or sores anywhere on the skin. It predominantly affects older individuals and those with prolonged exposure to the sun, highlighting the importance of UV protection.

Another formidable type is cutaneous lymphoma, which arises from the lymphocytes in the skin. This condition varies widely, encompassing both Hodgkin and non-Hodgkin lymphoma. It is more frequently diagnosed in men and the elderly and is challenging to understand fully due to its unpredictable occurrence without a clear causative factor.

Additionally, Kaposi sarcoma, linked to the Kaposi sarcoma-associated herpesvirus (KSHV), can develop in any part of the body and is especially prevalent among individuals with compromised immune systems. Unlike other cancers that directly relate to sun exposure, Kaposi sarcoma is viral-related.

What Are the Commonly Missed Signs of Skin Cancer?

The signs of skin cancer may not always be pronounced, making vigilance crucial.

Here are some less obvious indicators that require attention:

• Ugly Duckling Moles: Moles that significantly differ from others in terms of colour, size, or shape are known as "ugly ducklings." These anomalies might stand out as darker, evolve rapidly, or have unusual shapes and are prime candidates for medical evaluation.
• Hidden Melanomas: As mentioned, contrary to common belief, melanoma isn't exclusive to sun-exposed areas. It can manifest under nails as dark streaks or on less exposed skin like the soles or palms. These hidden melanomas often go unnoticed because they develop in areas typically covered by clothing or are less visible.
• Colour Variations: While melanomas are predominantly dark, they can exhibit a range of colours. They might show blue tinges due to the depth of pigmentation or red spots due to inflammation. Sometimes, melanomas appear as a rash and may adopt a pink colouration, especially if they respond poorly to typical skin treatments.
• Reactive Moles: Any mole that becomes itchy, painful, or starts changing texture, perhaps becoming scaly or starting to bleed, should be examined promptly. These changes can signify that the immune system has recognised an anomaly, potentially indicative of melanoma.

How is Skin Cancer Detected?

The detection of skin cancer involves a combination of clinical examinations and diagnostic tests.

Here's a breakdown of the general process:

• Dermatoscopic Examination: A dermatoscope is utilised to closely examine skin changes. This device provides a magnified view, allowing cancer specialists to detect potential skin cancer signs more accurately.
• Skin Biopsy: This is a crucial step where a small piece of suspicious skin is removed for detailed analysis. This procedure helps in confirming the presence of skin cancer cells.
• Comprehensive Testing: If skin cancer is confirmed, additional tests are conducted to assess the cancer's stage. This might include:
  • Blood Tests: These tests evaluate blood counts and chemistry to gauge overall health and organ function, particularly the liver and kidneys. They also measure levels of lactate dehydrogenase (LDH), an enzyme that, when elevated, can indicate the cancer's aggressiveness.
  • Imaging Scans: Techniques like CT scans are employed to check for any spread of cancer to lymph nodes or other organs.
  • Lymph Node Biopsy: Removing and examining tissue from lymph nodes close to the cancerous area helps determine if the cancer has spread.

Steps To Protect Yourself From Skin Cancer

While reducing exposure to UV radiation is crucial in lowering the risk of skin cancer, regularly checking your skin for suspicious changes is equally important in detecting the disease at its earliest stages.

Protecting yourself from skin cancer involves daily sun protection practices and regular skin checks.

To shield your skin, use a water-resistant, broad-spectrum sunscreen with a sun protection factor (SPF) of 30 or higher and a high UVA star rating (4 or 5 stars). This ensures you're protected from both UVA and UVB rays, which can contribute to skin cancer.

We strongly recommend scheduling a professional skin screening annually, as trained specialists can identify potential concerns that may be overlooked. In between appointments, perform self-checks every three months to monitor for new or changing moles.

If you notice any suspicious changes, visit a reputable skin cancer specialist in Singapore, such as OncoCare, promptly. Remember, regular skin checks can make a significant difference in detecting and treating cancerous moles.

Seeking Treatment For Skin Cancer

When it comes to addressing skin cancer symptoms, effective treatment strategies for skin cancer vary widely depending on several critical factors, ensuring each patient receives personalised care.

Here’s a general overview of the various options:

• Tailored Treatment Plans: The approach to treating skin cancer depends on the lesion's size, type, depth, and location, the stage at which the cancer was diagnosed, and the overall health of the patient.
• Surgical Options:
  • Excisional Surgery: Involves removing the cancerous tissue along with a margin of healthy skin. In cases where the cancer is more widespread, a wide excision may be necessary, possibly including the removal and biopsy of nearby lymph nodes to manage localised spread.
  • Mohs Micrographic Surgery: For recurring or difficult-to-treat skin cancers, this technique involves layer-by-layer removal under a microscope.
• Additional Therapies:

• • Cryotherapy: Employing liquid nitrogen, this treatment freezes and destroys precancerous and some early-stage skin cancer lesions, causing them to scab and fall off.
  • Radiotherapy: High-energy radiation beams target and destroy cancer cells, particularly useful when surgical removal isn’t feasible.
  • Chemotherapy: Applied topically for superficial cancers or systemically for advanced cases, chemotherapy uses potent drugs to target and kill cancer cells.

Navigating Skin Cancer Care 

At OncoCare, we understand the challenges and concerns that come with skin cancer. Our team of experienced cancer specialists in Singapore is dedicated to providing personalised care tailored to your needs. If you or your family members are facing skin cancer, our treatment options and compassionate approach can help guide you towards an appropriate course of action. Don't hesitate to reach out to us for advice and support throughout your skin cancer journey.

Remember, being aware of the hidden signs of skin cancer and taking proactive steps can significantly impact early detection and successful treatment outcomes. By staying informed and prioritising your skin health, you can take control of your well-being and enjoy a fulfilling and sun-safe life.

“Expert knowledge means better care for cancer”

Written by:

Dr Kevin Tay

MBBS (Singapore)

ABIM Int. Med (USA)

ABIM Med Onc (USA)

FAMS (Medical Oncology)