Melanoma

Causes

Melanoma is the most dangerous form of skin cancer, accounting for the majority of skin cancer-related deaths. It arises in the melanocytes, the pigment-producing cells in the skin. While it is less common than basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), melanoma is far more likely to spread (metastasize) to other parts of the body if not treated early.

Early detection is critical, as melanoma is highly curable in its early stages but becomes life-threatening when advanced.

Melanoma develops when the DNA in melanocytes is damaged, often by ultraviolet (UV) radiation from sunlight or tanning beds. This damage triggers genetic mutations that cause uncontrolled growth of these cells.

Key factors contributing to melanoma include:

• Intense UV Exposure: Severe, blistering sunburns during childhood or adolescence increase risk.
• Genetics: Family history of melanoma significantly raises the likelihood of developing the disease.
• Tanning Beds: Indoor tanning devices emit concentrated UV radiation, dramatically increasing melanoma risk, especially in young people.
• Weakened Immune System: Conditions or medications that suppress immune function elevate risk.

Symptoms

Melanoma often appears as a new mole or changes to an existing mole. A helpful guide for recognizing melanoma is the ABCDE Rule:

1. A – Asymmetry: One half of the mole doesn’t match the other half.
2. B – Border: Edges are irregular, blurred, or ragged.
3. C – Color: Multiple or uneven colors, including shades of black, brown, red, white, or blue.
4. D – Diameter: Larger than 6 millimeters (about the size of a pencil eraser), though melanomas can be smaller.
5. E – Evolving: Any changes in size, shape, color, or symptoms (such as bleeding, itching, or crusting).

Melanomas may also appear as unusual lesions on less sun-exposed areas, such as the palms, soles, or under the nails, especially in individuals with darker skin tones.

Types of Melanoma

Melanoma is categorized based on its growth pattern and characteristics:

1. Superficial Spreading Melanoma: The most common type, it grows along the top layer of skin before penetrating deeper.
2. Nodular Melanoma: A more aggressive form that grows quickly and appears as a raised, often dark-colored bump.
3. Lentigo Maligna Melanoma: Common in older adults, it starts as a flat, slowly growing lesion on sun-damaged skin.
4. Acral Lentiginous Melanoma: Rare but more common in people with darker skin tones, it appears on the palms, soles, or under nails.
5. Desmoplastic Melanoma: A rare type that develops in areas of chronic sun damage and can be harder to detect.

Treatment

Treatment depends on the stage of melanoma, ranging from localized to advanced disease. Early-stage melanomas are highly curable, while advanced stages require more aggressive treatment.

1. Surgical Treatments
   • Wide Excision: Removal of the melanoma and a margin of healthy tissue to ensure complete excision.
   • Sentinel Lymph Node Biopsy: Performed if melanoma is suspected to have spread. If cancer is detected in the lymph nodes, additional surgery may be needed.
2. Advanced TreatmentsFor metastatic or high-risk melanoma, systemic therapies are used:
   • Immunotherapy: Drugs like nivolumab and pembrolizumab help boost the immune system to attack cancer cells.
   • Targeted Therapy: For melanomas with specific genetic mutations (e.g., BRAF mutations), drugs like vemurafenib and dabrafenib target cancer cell growth.
   • Chemotherapy: Less commonly used but may be an option for some advanced cases.
   • Radiation Therapy: Often used to control symptoms in advanced stages or for brain metastases.
3. Experimental TreatmentsClinical trials exploring new therapies, such as oncolytic virus therapy and personalized cancer vaccines, offer hope for advanced melanoma patients.