Understanding melanoma

Dr Rakesh Newaj explains how melanoma develops and the risk factors to look out for.

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Melanoma, a term often heard but not always fully understood, is a type of cancer that originates from melanocytes (cells responsible for producing pigment, primarily found in the skin). While melanocytes are most commonly located in the skin’s upper layer (epidermis), they can also be found in the brain and eyes. Their primary function is to safeguard the skin from the harmful effects of ultraviolet (UV) rays.

However, when these cells undergo abnormal mutations and begin to multiply uncontrollably, they give rise to melanoma. Typically, melanomas are identified by their darker pigmentation, although there exists a rare colourless variant.

Unlike more common skin cancers, such as basal cell and squamous cell carcinomas, melanoma rarely develops from moles, with only approximately 1 in 60 000 moles eventually turning into melanomas. Instead, most melanomas emerge directly from normal skin. Therefore, it’s crucial to be vigilant and seek medical attention if you notice any new, dark lesions on your skin. Melanoma can affect people of any age, making awareness and early detection essential for everyone.

Risk factors

Recognising risk factors is of paramount importance. These can be categorised into three main groups: genetic factors, environmental factors, and the phenotypic manifestations resulting from gene-environment interactions.

Genetic factors: Genetic susceptibility to melanoma may involve inheriting a sun-sensitive genotype or specific melanoma susceptibility genes.

Factors such as the ability to tan or susceptibility to sunburn, having very fair skin, red hair colour, and certain genetic conditions like xeroderma pigmentosum can increase the risk. Additionally, a family history of melanoma raises the likelihood of developing this form of cancer. 

Environmental factors: The primary environmental risk factor for melanoma is excessive exposure to ultraviolet (UV) radiation, particularly in fair-skinned individuals. This exposure often results from sunbathing, working outdoors, or residing in regions closer to the equator. The use of tanning beds, which emit UV radiation, is another source of risk.

Phenotypic expressions of gene/environmental interactions: Specific physical characteristics can also contribute to melanoma risk, such as having a high number of moles (>100), multiple atypical moles, freckles, and a history of previous melanoma.

Diagnosis

Melanoma presents in various forms, with superficial spreading melanoma being the most common. This type typically appears on the trunk and legs. Other less common variants include nodular melanoma, lentigo maligna melanoma, acral lentiginous melanoma, and amelanocytic melanoma.

If you have one or more of the mentioned risk factors, you should undergo regular check-ups with a dermatologist. Vigilant monitoring of moles and other dark lesions on the skin is essential. An easy way to remember what to look for is through the ABCDE method.

If any suspicions arise, it’s imperative to schedule an immediate appointment with a general practitioner or, preferably, a dermatologist. The healthcare provider will evaluate the concerning lesion and perform a comprehensive skin examination. In cases where melanoma is suspected, a biopsy or, if feasible, complete removal of the lesion will be conducted, followed by laboratory analysis.

Treatment

The treatment approach is determined by its stage. Treatment options may include wider excisions only, lymph node removal, and referral to an oncologist for further assessment, including the consideration of chemotherapy if necessary.

While melanoma is a potentially deadly cancer, early detection and prompt treatment often lead to a successful outcome. It can’t be stressed enough that individuals with risk factors should undergo regular check-ups, and any suspicious skin changes must be promptly reported to medical professionals.

We as dermatologists, underscore the importance of awareness, early detection, and proactive healthcare measures in combating melanoma.

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