Skin Cancer | Causes, Symptoms, Treatment

Skin Cancer | Causes, Symptoms, Treatment

Medically reviewed by MyHSN team – last update May 2026

Skin cancer is one of the commonest cancers. It is an abnormal, uncontrolled growth of skin cells that is most frequently triggered by harmful ultraviolet radiation from sunlight or tanning beds.

Fortunately, when caught early through routine self-examinations, the vast majority of cases are highly treatable and curable.

1. 3 Main Types of Skin Cancer

• Basal Cell Carcinoma (BCC): The most common form of skin cancer, originating in the basal cells of the outer skin layer. It grows very slowly and rarely spreads, but can cause localised tissue destruction if neglected.

• Squamous Cell Carcinoma (SCC): The second most common type, arising from flat squamous cells. It is generally non-aggressive but carries a higher risk than BCC of spreading to nearby lymph nodes.

• Melanoma: The most aggressive and dangerous form of skin cancer. It develops in pigment-producing melanocytes, growing rapidly and spreading (metastasizing) to internal organs if left untreated.

2. Primary Causes and Risk Factors

• Ultraviolet (UV) Radiation: The primary trigger for skin cancer. Both intense, blistering sunburns and long-term, chronic exposure to natural sunlight or artificial tanning beds mutate skin cell DNA.

• Skin Phenotype: Individuals with fair skin, light-colored eyes, blond or red hair, and a tendency to freckle or burn easily lack protective melanin, though skin cancer can develop in all skin tones.

• Mole Abundance: Possessing a high total number of moles (especially over 50) or having atypical moles (dysplastic nevi) statistically increases the risk of developing melanoma.

• Immune Suppression: A weakened immune system—whether from chronic medical conditions, illness, or organ transplant anti-rejection medications—increases susceptibility to skin malignancies.

3. Symptoms: ABCDE Guide for Melanoma

• Asymmetry: One half of the suspicious mole or spot does not physically match the appearance of the other half.

• Border: The edges of the lesion are irregular, ragged, notched, blurred, or poorly defined against normal skin.

• Color: The pigmentation is non-uniform, featuring varying shades of brown, black, pink, red, white, or blue.

• Diameter: The spot is typically larger than 6 millimeters across (roughly the size of a standard pencil eraser), though some can be smaller.

• Evolving: The mole is actively changing in size, shape, color, or elevation over time, or begins to itch, bleed, crust, or ooze.

4. Symptoms: Non-Melanoma Skin Cancers

• Basal Cell Carcinoma Signs: Often presents as a shiny, pearly, or translucent bump that can be pink, white, or skin-colored. It may also look like a firm scar-like lesion or a sore that bleeds and fails to heal.

• Squamous Cell Carcinoma Signs: Typically appears as a firm, red nodule or a flat, rough lesion with a scaly, crusty surface that may feel tender to the touch.

• Actinic Keratosis: A precancerous skin lesion presenting as a small, rough, sandpaper-like patch. If left untreated, a small percentage can progress directly into squamous cell carcinoma.

5. Diagnosis

• Visual Skin Examination: A dermatologist inspects the skin from head to toe, using a specialized magnifying tool called a dermatoscope to analyse localized pigment patterns.

• Skin Biopsy: The definitive diagnostic tool. Under local anesthesia, the clinician removes all or part of the suspicious lesion for microscopic laboratory analysis by a pathologist.

• Staging Investigations: For advanced melanoma or aggressive SCC, additional tests—such as a sentinel lymph node biopsy, CT scans, or MRI scans—are utilized to determine if the cancer has spread.

6. Standard Surgical Treatments

• Surgical Excision: The doctor numbs the area, cuts out the visible tumor along with a surrounding safety margin of normal, healthy skin, and stitches the wound closed.

• Mohs Micrographic Surgery: A highly specialized procedure for sensitive areas like the face. The surgeon removes the cancer layer by layer, mapping and examining each under a microscope immediately until zero cancer cells remain.

• Curettage and Electrodessication: Used for small, superficial BCCs. The doctor scrapes away the soft cancer cells using a sharp instrument (a curette) and applies electrical heat to stop bleeding and destroy remaining cells.

7. Non-Surgical Treatments

• Cryotherapy: The direct application of liquid nitrogen to freeze and destroy superficial or precancerous skin cells. The area blisters, crusts over, and heals with healthy tissue.

• Topical Medications: Prescription creams or gels containing chemotherapy agents (such as 5-fluorouracil) or immune response modifiers (like imiquimod) applied directly to superficial lesions.

• Radiation Therapy: Targeted, high-energy X-ray beams used to destroy malignant cells. This serves as an alternative for patients unable to undergo surgery or for tumors in complex anatomical locations.

8. Modern Therapies for Advanced Cancer

• Immunotherapy: Advanced systemic drugs (such as pembrolizumab) that boost the body’s own immune system to recognize and aggressively destroy metastasized cancer cells, significantly improving melanoma survival rates.

• Targeted Therapy: Precision medications designed to block specific genetic pathways and mutations (such as the BRAF mutation) that tell cancer cells to grow and divide.

• Systemic Chemotherapy: Traditional cancer drugs given orally or intravenously to kill rapidly dividing cells, though rarely used as a first-line treatment today due to superior immunotherapy options.

9. Prevention

• Broad-Spectrum Sunscreen: Apply a broad-spectrum sunscreen with an SPF of 30 or higher daily, even on cloudy days, reapplying every two hours or immediately after swimming or sweating.

• Seek Shade: Limit direct exposure to sunlight during peak hours from 10:00 AM to 4:00 PM, when ultraviolet rays are at their highest intensity.

• Protective Clothing: Wear tightly woven garments, UV-blocking sunglasses, and a wide-brimmed hat that effectively shades the face, neck, and ears.

• Avoid Artificial UV: Completely avoid tanning beds and sunlamps, as their concentrated UV radiation directly damages vascular structures and spikes melanoma risk.

10. Early Detection

• Monthly Self-Examinations: Establish a habit of inspecting your entire skin surface once a month using full-length and hand mirrors to check hard-to-see areas like the back and scalp.

• Documenting Moles: Track your existing pattern of freckles and blemishes to quickly identify new spots or changes in old lesions.

• Professional Screening: Schedule an annual professional skin exam with a dermatologist if you have an elevated risk profile or a family history of skin cancer.

• Prompt Action: Schedule an immediate medical evaluation for any spot that matches the ABCDE criteria, displays the “ugly duckling” sign (looks different from all other moles), or refuses to heal.

Comparison of Skin Lesions

Clinical Note: If you find a sore that does not heal within four weeks, or a mole that starts to crust, bleed, or change colour, consult a GP or dermatologist. Early detection through AI-assisted screening makes skin cancer one of the most treatable diseases in modern medicine.