Understanding Skin Cancers: Types, Symptoms, and Treatment Options

Skin cancer, originating in the epithelial tissue, represents the most prevalent form of cancer globally. It can involve the skin's surface or internal organs like the liver or kidneys. Depending on the case, the cancer may stay localized or spread to other regions. Early detection is vital, especially since metastatic skin cancers can be life-threatening. Recognizing the different types, symptoms, and risk factors is essential for prompt diagnosis and effective treatment.

Types of skin carcinoma

Carcinomas are classified based on the specific cell type they arise from, with multiple types sometimes occurring simultaneously in the same organ.

Common subtypes include:

Basal cell carcinoma: This is primarily a skin cancer, accounting for most non-melanoma cases. It tends to grow slowly and rarely spreads. Excessive sun exposure is its main cause.

Squamous cell carcinoma: Often linked to skin cancer, this type can affect not only skin but also other organs like the lungs, esophagus, and head & neck. It accounts for approximately 25% of lung cancers.

Kidney cancer (renal cell carcinoma): Nearly 90% of kidney tumors are renal cell carcinomas, which typically form a solitary mass.

Transitional cell carcinoma: Found in the lining of the kidneys and ureters, it makes up about 10% of kidney cancers.

Glandular carcinomas (Adenocarcinomas): Originating from secretory epithelial cells, these include cancers such as colorectal, pancreatic, prostate, breast, and lung cancers.

After diagnosis, carcinomas are classified further based on their spread:

Carcinoma in situ: Confined to the original epithelial layer, not spreading further.

Invasive carcinoma: Has penetrated neighboring tissues but remains local.

Metastatic carcinoma: Has spread to distant body parts.

Signs and symptoms of skin cancer

Regular skin examinations are crucial for early detection. Changes such as new growths or sores that do not heal, which may appear as patches, rashes, or crusty areas, should prompt immediate medical review. Skin cancers can sometimes bleed or change in appearance as they progress. Notably, early-stage skin cancers are often visible and accessible for observation, aiding early diagnosis.

Symptoms vary by carcinoma type:

Basal cell carcinoma: Usually appears as a pale or translucent bump with a waxy appearance and blood vessels at the center. It may resemble a scar or flesh-colored lesion and can bleed or crust over time.

Squamous cell carcinoma: Often presents as a rough, reddened lump or scaly patch that doesn't resolve. It frequently appears on the arms, head, or neck, and can expand slowly.

Merkel cell carcinoma: Rapidly growing, flesh-colored, raised moles commonly found on sun-exposed areas like the face or neck.

Causes and risk factors

Ultraviolet (UV) radiation from sun exposure is the primary cause of many skin cancers. Excessive exposure from tanning beds and sunlamps increases risk further. UV damage causes DNA mutations in skin cells, leading to uncontrolled growth. Risk factors include fair skin, family history, presence of numerous moles or freckles, autoimmune diseases, inherited syndromes, weakened immunity, and certain viruses like HPV. Precancerous lesions such as actinic keratosis also elevate the risk. Damage from chemicals, X-ray exposure, and burns can contribute to squamous cell carcinoma.

Diagnosing skin cancer

Diagnosis involves a thorough physical exam, including assessment of skin lesions' shape, size, and texture. Photography may be used for monitoring. Medical history provides additional clues. A biopsy confirms the diagnosis if malignancy is suspected.

Treatment approaches

Management depends on the tumor’s size, type, stage, and location. A multidisciplinary team—including dermatologists, surgeons, and oncologists—collaborates for optimal results. Common treatments include:

Electrodesiccation and curettage: Scraping and cauterizing small lesions.

Surgical removal: Mohs micrographic surgery is highly effective, especially for larger or recurrent lesions.

Cryosurgery: Freezing tumors with liquid nitrogen to induce cell death.

Topical medications: Applying chemotherapeutic agents directly on skin lesions, with minimal side effects.

Radiation therapy: Targeted radiation for larger or difficult-to-remove tumors.

Laser therapy: Use of lasers to vaporize or obliterate cancerous tissue.