Effect of age on melanoma risk, prognosis and treatment response

As for all types of cancer, the incidence of melanoma increases with age. However, naevus counts (the principal risk factor for melanoma) decrease with age; hence the relationship between ageing and melanoma is complex. Subjects who maintain a high naevus count after the age of 50 years are more likely to be affected by melanoma, as their lesions do not senesce. Longer telomere length, which is strongly related to age, is linked to high naevus counts/melanoma risk; thus melanoma biology is influenced by factors that slow down ageing. Age is also an important prognostic factor in melanoma. Increasing age leads to worse survival in stages I, II and III. Sentinel lymph node (SLN) status, which is a strong predictor of melanoma survival, is also affected by age, as SLN positivity decreases with age. However, the prognostic value of SLN on survival increases with age, so, again, these relationships are complex. In patients with stage IV melanoma, age impacts on survival because it affects responses to treatment. This review examines the effects of age on melanoma risk, prognostic factors and responses to treatment.