Overview

Skin cancer is a broad term for malignant growths that arise from the skin's cells. Most originate in the epidermis, the outermost skin layer, and are named for the cell type involved. While many forms are highly treatable when found early, some can invade surrounding tissue or spread to other organs. Public awareness of skin changes and timely medical evaluation improves outcomes.

Major types and characteristics

The two broad categories commonly used are melanoma and non-melanoma skin cancers. Melanoma develops from pigment-producing melanocytes and is less common but more likely to metastasize. Non-melanoma cancers include basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), which arise from different layers of epidermal cells and together make up the majority of skin cancer diagnoses.

  • Melanoma: often appears as a new or changing mole; asymmetry, irregular borders, color variation, diameter growth, or evolution are warning signs.
  • Basal cell carcinoma: typically a pearly or translucent bump, often on sun-exposed areas; it grows slowly and rarely spreads but can cause local destruction.
  • Squamous cell carcinoma: may appear as a scaly patch, ulcer, or firm nodule and has a higher risk of spreading than BCC if untreated.

Causes and risk factors

The principal and most modifiable risk factor for most skin cancers is ultraviolet (UV) radiation from the sun and artificial tanning devices. Other contributors include fair skin that burns easily, a history of severe sunburns, many moles, older age, genetic predisposition, and immunosuppression. For background on UV and skin biology see UV radiation and general epidermis resources. For how skin cancer relates to overall cancer patterns, comparison links include lung, breast, colorectal, and prostate cancers.

Detection, diagnosis and staging

Many skin cancers are visible and detected by patients or clinicians during routine skin examinations. Suspicious lesions are examined and usually biopsied to confirm the diagnosis and determine the precise cell type. Staging — assessing depth, size, and whether spread has occurred — guides treatment planning. For general information about cell types and pathology, see cell origins.

Treatment and prognosis

Treatment depends on type, size, location and stage. Common approaches include surgical excision, Mohs micrographic surgery (precise removal for certain BCCs and SCCs), topical therapies for very superficial lesions, radiation for selected cases, and systemic options for advanced disease. In recent years, targeted therapies and immunotherapy have improved outcomes for advanced melanoma. Overall, early-detected skin cancers have high cure rates; melanoma outcomes are closely tied to early diagnosis.

Prevention and public health

Prevention focuses on reducing UV exposure: seeking shade, wearing protective clothing and broad-spectrum sunscreen, avoiding tanning beds, and performing regular skin self-exams. Public education and screening in high-risk groups help lower morbidity. For a concise primer, see basic skin cancer information and a focused overview on melanoma signs. For details about non-melanoma forms, consult resources on basal and squamous cell behavior.

Further notes and resources

Because skin cancers are common but often preventable and treatable, prompt attention to changing lesions is important. For more reading and patient-focused guidance, explore the linked resources above or speak with a dermatology professional. Additional reference material is available via skin anatomy, clinical summaries at cancer overview, and specialized melanoma resources at melanoma information and treatment summaries. For research updates and public guidance consult sites noted at clinical resources and sun-safety campaigns.