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.

A family history of melanoma greatly increases the risk of developing cutaneous melanoma, a highly aggressive skin cancer whose incidence has been steadily increasing worldwide. Familial melanomas account for about 10% of all malignant melanomas and display an inheritance pattern consistent with the presence of pathogenic germline mutations, among which those involving CDKN2A are the best characterized. In recent years, a growing number of genes, such as MC1R, MITF, CDK4, POT1, TERT, ACD, TERF2IP, and BAP1, have been implicated in familial melanoma. The fact that individuals harboring these germline mutations along with their close blood relatives have a higher risk of developing multiple primary melanomas as well as other internal organ malignancies, especially pancreatic cancer, makes cascade genetic testing and surveillance of these families of the utmost importance. Unfortunately, due to a polygenic inheritance mechanism involving multiple low-risk alleles, genetic modifiers, and environmental factors, it is still very difficult to predict the presence of these mutations. It is, however, known that germline mutation carriers can sometimes develop specific clinical traits, such as high atypical nevus counts and specific dermoscopic features, which could theoretically help clinicians predict the presence of these mutations in prone families. In this review, we provide a comprehensive overview of the high- and intermediate-penetrance genes primarily linked to familial melanoma, highlighting their most frequently associated non-cutaneous malignancies and clinical/dermoscopic phenotypes.