Skin cancer is the abnormal growth of skin cells, most commonly triggered by exposure to ultraviolet (UV) radiation from the sun or tanning beds. It is the most common type of cancer worldwide but is highly treatable when detected early. Skin cancer primarily affects areas exposed to the sun, such as the face, neck, hands, and arms, though it can develop anywhere on the body.
Types of Skin Cancer
Basal Cell Carcinoma (BCC):
• Most common form of skin cancer.
• Appearance: BCC usually appears as a pearly or waxy bump, a flat, flesh-colored or brown scar-like lesion, or a sore that heals and then reopens.
• Risk: Grows slowly and rarely spreads (metastasizes), but it can invade nearby tissues if not treated.
• Common locations: Often found on sun-exposed areas like the face, neck, or hands.
Squamous Cell Carcinoma (SCC):
• Second most common form of skin cancer.
• Appearance: SCC may appear as a firm, red nodule, a flat lesion with a scaly, crusted surface, or a sore that doesn’t heal.
• Risk: It can spread to deeper layers of skin and nearby lymph nodes if left untreated.
• Common locations: Sun-exposed areas like the face, ears, neck, lips, and hands.
Melanoma:
• Most dangerous form of skin cancer, as it can spread rapidly to other organs.
• Appearance: Melanoma may appear as a large, brownish spot with darker speckles, a mole that changes in size, color, or feel, or a lesion with an irregular border and multiple colors (black, brown, tan, or pink).
• Risk: Melanoma is more likely to spread (metastasize) than BCC or SCC and is potentially life-threatening if not caught early.
• Common locations: Can develop anywhere on the body, even in areas not exposed to the sun, but often appears on the back, legs, arms, and face.
Other Less Common Types of Skin Cancer
Merkel Cell Carcinoma: A rare and aggressive cancer that forms as firm, red or purple nodules on or just beneath the skin.
Kaposi Sarcoma: Associated with weakened immune systems, this cancer causes lesions that appear as red or purple patches on the skin or mucous membranes.
Sebaceous Gland Carcinoma: A rare cancer that originates in the oil glands of the skin, often appearing as a firm, painless nodule.
Causes and Risk Factors
UV Radiation: Prolonged exposure to ultraviolet rays from the sun or tanning beds is the most significant risk factor.
Fair Skin: People with lighter skin, less melanin, and those who sunburn easily are at higher risk.
Family or Personal History: A history of skin cancer increases the risk of developing it again.
Moles: Having many moles or abnormal moles (dysplastic nevi) increases the risk of melanoma.
Immune Suppression: People with weakened immune systems, such as those who have undergone organ transplants, are at higher risk.
Exposure to toxins: Certain chemicals, like arsenic, may increase skin cancer risk.
Age: The risk increases with age, though younger people can also develop skin cancer, particularly melanoma.
Symptoms of Skin Cancer
New growth: Any new growth on the skin that looks unusual or changes over time.
Non-healing sores: Sores or ulcers that do not heal within a few weeks.
Changes in moles: Moles that change in color, size, shape, or texture, or that start to bleed or itch.
The ABCDE Rule for Melanoma
The ABCDE rule can help detect early signs of melanoma:
A for Asymmetry: One half of the mole or lesion does not match the other half.
B for Border: The edges are irregular, ragged, or blurred.
C for Color: The color is uneven, with varying shades of brown, black, tan, or even red, white, or blue.
D for Diameter: The lesion is larger than 6 mm (about the size of a pencil eraser).
E for Evolving: The mole or lesion changes in size, shape, color, or elevation, or starts to show new symptoms like bleeding or itching.
Diagnosis of Skin Cancer
Skin examination: A dermatologist will visually inspect the skin and assess any suspicious lesions.
Biopsy: If the doctor suspects skin cancer, a biopsy is done by removing part or all of the lesion to be examined under a microscope.
Treatment Options
The treatment depends on the type, size, location, and stage of the cancer. Common treatment approaches include:
Surgical removal:
• Excision: Cutting out the cancerous tissue along with a margin of healthy skin.
• Mohs surgery: A precise surgical technique used primarily for BCC and SCC. It involves removing skin layers one at a time and examining them until no more cancer cells are detected.
Cryotherapy: Freezing the cancer cells with liquid nitrogen, typically used for early-stage skin cancers or precancerous lesions (actinic keratoses).
Radiation therapy: Often used for larger or more difficult-to-treat areas, especially in older patients or those with inoperable skin cancers.
Chemotherapy: Topical chemotherapy (using creams or lotions) can treat superficial cancers, while systemic chemotherapy may be used for more advanced stages.
Immunotherapy: Drugs like pembrolizumab (Keytruda) or nivolumab help boost the immune system’s ability to fight melanoma or advanced skin cancers.
Targeted therapy: For certain types of melanoma with specific gene mutations, targeted drugs like vemurafenib and dabrafenib can be effective.
Prevention of Skin Cancer
Sun protection: Wear sunscreen with broad-spectrum SPF 30 or higher daily, even on cloudy days, and reapply regularly.
Avoid tanning beds: UV radiation from tanning beds is just as harmful as sunlight.
Wear protective clothing: Long sleeves, hats, and sunglasses help shield the skin from UV radiation.
Seek shade: Especially during peak sunlight hours (10 a.m. to 4 p.m.).
Regular skin checks: Perform self-examinations and see a dermatologist for routine skin checks, especially if you have risk factors.
Early detection of skin cancer is key to successful treatment. If you notice any new or changing skin lesions, see a healthcare professional for evaluation.