Melanoma is a type of cancer that originates in melanocytes, which are specialized cells in the skin responsible for producing melanin, the pigment that gives skin its color. This cancer is known for its ability to spread rapidly and recur frequently, making it one of the most serious forms of skin cancer[1]. Melanoma can develop anywhere on the body but is most commonly found on areas exposed to the sun, such as the trunk, legs, and upper back. It can arise from an existing mole or appear as a new lesion on the skin[2].
The primary cause of melanoma is damage to the DNA within melanocytes, most often due to ultraviolet (UV) radiation from sunlight or artificial sources like tanning beds. This DNA damage disrupts the normal control of cell growth and division, leading to uncontrolled proliferation of melanocytes and the formation of cancerous tumors[1]. People with fair skin, a tendency to freckle, a large number of moles, or a family history of melanoma are at higher risk. White individuals are about 20 times more likely to develop melanoma than Black individuals[1][3].
A significant genetic factor in melanoma development involves mutations in the BRAF gene. This gene encodes a protein called B-raf, which normally helps regulate cell growth and survival. Mutations in BRAF cause the protein to become permanently active, sending continuous signals that promote cell division and prevent programmed cell death (apoptosis). This leads to the uncontrolled growth of melanocytes and the formation of melanoma tumors. These mutations are often acquired through excessive UV exposure[1].
There are several types of melanoma, each with distinct characteristics:
1. Superficial spreading melanoma is the most common type, accounting for about 70 percent of cases. It typically starts as a flat or slightly raised patch with irregular borders and varied colors, including tan, brown, black, red, blue, or white. This type often begins in younger individuals and grows along the skin surface before invading deeper layers[2].
2. Lentigo maligna melanoma usually affects older adults and appears as a flat or mildly elevated mottled patch of tan or brown color. It remains close to the skin surface for a long time before becoming invasive[2].
3. Nodular melanoma is more aggressive and invasive from the start, often appearing as a raised bump that can be black, blue, or red.
4. Acral lentiginous melanoma occurs on less sun-exposed areas such as the soles of the feet or under the nails and is more common in people with darker skin tones[2][3].
Melanoma can be identified early by observing changes in moles or new skin lesions using the ABCD rule: Asymmetry (one half unlike the other), Border irregularity, Color variation, and Diameter larger than 6 millimeters. Other warning signs include inflammation, darkening, or spreading of a mole[4].
If melanoma is detected early, it can often be treated successfully with surgical removal. However, if it spreads beyond the skin to other parts of the body—a condition known as metastatic melanoma—it becomes more difficult to treat. Melanoma cells can spread through the bloodstream or lymphatic system to organs such as the lungs, liver, brain, bones, and lymph nodes[5]. Metastatic melanoma requires more complex treatments, including immunotherapy, targeted therapy, chemotherapy, or radiation[7].
Preventing melanoma involves protecting the skin from UV radiation by avoiding excessive sun exposure, especially during peak hours, wearing protective clothing and hats, using broad-spectrum sunscreen, and avoiding tanning beds. Regular skin examinations and awareness of changes in moles or new skin growths are crucial for early detection[3][6].
The incidence of melanoma has been increasing, particularly among fair-skinned populations in regions with high UV exposure. Early diagnosis significantly improves survival rates, making education and vigilance essential in managing this potentially deadly cancer[3].
Sources:
[1] Britannica – Melanoma
[2] Discover Plastic Surgery – Melanoma Richmond VA
[3] EBSCO – Melanomas Research Starters
[4] Marie Keating Foundation – Melanoma
[5] HealthyWomen – Metastatic Melanoma 101
[6] Vita Health Group – Mole Awareness: Non-melanoma and Melanoma Skin Cancer Explained
[7] News Medical – Melanoma News, Articles and Research
