Melanoma Risk Factors
The most critical melanoma risk factors, in order of importance, are: UV radiation exposure (especially intermittent intense exposure and sunburns), fair skin phenotype, multiple or atypical moles, personal or family history of melanoma, older age, male sex, immunosuppression, and specific genetic mutations. 1
Environmental Risk Factors
UV Radiation Exposure
- UV radiation from sun exposure, indoor tanning beds, and other UV-emitting devices is the major environmental risk factor for melanoma 1
- Intermittent intense sun exposure (rather than chronic exposure) greatly increases melanoma risk 2, 3
- History of frequent sunburns is a major independent risk factor 1, 4
- Indoor tanning bed use is particularly important in adolescents 1
Host/Phenotypic Risk Factors
Skin Characteristics
- Fair skin that is more susceptible to sunburning represents a major risk factor 1
- Light-colored eyes (blue or green) increase risk 1
- Red or blond hair color elevates risk 1
- These phenotypic traits explain why melanoma incidence is substantially higher among White persons compared to other races and ethnicities 1
Moles and Pigmented Lesions
- Higher numbers of moles on the skin (especially >50 moles) constitute substantially increased risk 1
- Atypical (dysplastic) moles significantly elevate risk 1, 5
- Giant congenital pigmented hairy naevi require long-term monitoring due to greatly increased risk (>10 times general population) 1
- Congenital moles in general increase risk 5
Personal and Family History
Previous Melanoma
- Patients with a previous primary melanoma have an 8-10 times increased risk and face a 4-8% lifetime risk of developing a second primary melanoma 1
- This warrants lifetime dermatologic surveillance 1
Family History
- Family history of three or more melanoma cases, or melanoma plus pancreatic cancer, indicates greatly increased risk (>10 times general population) requiring referral to clinical genetics 1
- Two family members with melanoma may also warrant genetic counseling, especially if one had multiple primaries or atypical mole phenotype 1
- Familial atypical mole and melanoma syndrome represents high-penetrant genetic risk 1, 3
Demographic Factors
- Older age increases risk, with average diagnosis at age 65 6
- Male sex is associated with higher risk and mortality 1
- Melanoma is most common in white, older men 6
Immunosuppression
- Organ transplant recipients have moderately increased risk (8-10 times general population) 1
- General immunosuppression elevates risk 5
Special Considerations by Race/Ethnicity
While melanoma is more common in White populations, acral lentiginous melanoma—occurring on palms, soles, or under nails—is the most common type among Black populations 1. This subtype occurs on skin not frequently exposed to direct sunlight, representing a different pathophysiology.
Risk Stratification for Clinical Practice
Moderately Increased Risk (8-10x general population):
- Previous primary melanoma 1
- Large numbers of moles with some clinically atypical 1
- Organ transplant recipients 1
Greatly Increased Risk (>10x general population):
- Giant congenital pigmented hairy naevus 1
- Family history of ≥3 melanomas or melanoma plus pancreatic cancer 1
- Familial atypical mole and melanoma syndrome 1
Critical Pitfalls to Avoid
- Do not dismiss changing moles in adults or new moles appearing after puberty—these warrant urgent specialist referral 1
- Do not overlook acral sites (palms, soles, nails) in patients with darker skin, as acral lentiginous melanoma is the predominant type in these populations 1
- Do not remove suspicious lesions in primary care—specialist excision with proper margins and pathologic correlation is essential for accurate staging and prognosis 1