Skin cancer is the most commonly diagnosed cancer in the United States and many other countries with predominantly fair-skinned populations. The three main types — basal cell carcinoma (BCC), squamous cell carcinoma (SCC), and melanoma — differ fundamentally in their origin, behaviour, and prognosis. BCC and SCC are highly curable when treated early. Melanoma, while less common, is responsible for the vast majority of skin cancer deaths due to its propensity for early metastasis — making early detection critical.
The ABCDEs of Melanoma Detection
The ABCDE rule provides a systematic framework for evaluating suspicious skin lesions: A — Asymmetry: one half does not mirror the other; B — Border: irregular, ragged, notched, or blurred edges rather than smooth, well-defined margins; C — Colour: variation within the lesion — shades of brown, black, pink, red, white, or blue; D — Diameter: larger than 6 mm (about the size of a pencil eraser), though melanomas can be smaller; E — Evolving: any change in size, shape, colour, or new symptom (bleeding, itching, crusting) over weeks to months. Any lesion meeting one or more of these criteria warrants prompt dermatological evaluation. Additionally, the "ugly duckling" sign — a lesion that looks noticeably different from surrounding moles — is a clinically useful heuristic.
Sun Protection and Prevention
Ultraviolet radiation — from sunlight and artificial tanning devices — is the primary environmental cause of skin cancer. Evidence-based sun protection includes: applying broad-spectrum SPF 30+ sunscreen (SPF 50+ for prolonged sun exposure) to all exposed skin every two hours and after swimming or sweating; seeking shade between 10 a.m. and 4 p.m. when UV index is highest; wearing protective clothing (long sleeves, wide-brimmed hats, UV-blocking sunglasses); and completely avoiding tanning beds — a single session before age 35 increases melanoma risk by 59%. Cumulative UV exposure drives BCC and SCC risk; episodes of sunburn, especially in childhood, are particularly strongly associated with melanoma.
Frequently Asked Questions
How often should I have a professional skin check?
Annual full-body skin examination by a dermatologist is recommended for individuals with a personal or family history of skin cancer, multiple atypical moles, fair skin, or significant occupational or recreational sun exposure. Average-risk individuals should perform monthly self-examination and discuss screening intervals with their primary care physician.
Can dark-skinned individuals get skin cancer?
Yes. While darker skin provides greater UV protection due to higher melanin content, it does not confer immunity. Skin cancer in people with darker skin is often diagnosed at more advanced stages, partly due to lower awareness and partly because it more frequently occurs in atypical locations (palms, soles, nail beds) not typically associated with sun exposure — a presentation known as acral lentiginous melanoma.
Sources
- American Academy of Dermatology. Skin Cancer. 2023.
- Skin Cancer Foundation. Prevention guidelines. 2023.
- WHO. Skin cancers. 2023.