Subtype-Specific Insights into Melanoma in Iceland

A population-based analysis from the Icelandic Cancer Registry, recently published in the British Journal of Dermatology, provided valuable insights into the long-term incidence and clinical impact of melanoma subtypes from 1955 to 2023.¹ For dermatology clinicians, the findings highlight shifting patterns in disease presentation, sex differences in risk, and the urgent need for vigilance around aggressive melanoma subtypes.

The study identified 1,811 invasive melanomas during the 68-year period, with 748 in men and 1,063 in women. Cases were stratified into superficial spreading melanoma (SSM), nodular melanoma (NM), lentigo maligna melanoma (LMM), and acral lentiginous melanoma (ALM). SSM accounted for the majority of cases at 72%, followed by NM at 16%, LMM at 8.9%, and ALM at 2.5%. Gender differences were notable: researchers noted women more often presented with thinner SSM lesions located on the legs, while men more frequently developed thicker lesions involving the head, neck, and trunk.

Incidence trends varied considerably by subtype. In men, the study found SSM rates rose until 2003, with an annual percent change (APC) of 7.13%, before entering a period of modest decline at an APC of −1.34%. Among women, rates increased sharply until 2001 (APC 7.32%) and then decreased more steeply (APC −2.03%). The majority of SSM in women involved thin melanomas measuring less than 1 mm, suggesting earlier detection. In contrast, NM showed a worrisome pattern, with a notable rise in men between 2016 and 2023 (APC 12.03%). Given the aggressive vertical growth associated with NM and its frequent presentation at a late stage, this increase is of particular clinical concern. LMM and ALM, by comparison, remained relatively stable across the study period, consistent with global observations.

These subtype-specific shifts can be understood in part through environmental and behavioral influences. Rising melanoma rates in Iceland in the 1980s coincided with increased tanning bed use and greater international travel, both of which elevated UV exposure. The subsequent decline in SSM appears to reflect improved public awareness of UV risks, stricter adherence to sun-protection practices, and earlier detection.² These factors may also explain the relative rise in in situ melanoma diagnoses reported in other Icelandic studies. The lower incidence of LMM compared to global averages likely reflects Iceland’s reduced cumulative UV exposure due to its northern latitude. However, the relatively high proportion of SSM underscores that UV-seeking behavior remains an important contributor despite environmental limitations.

For clinicians, the findings carry several important implications. The rising incidence of NM in men reinforces the need for heightened awareness and a low threshold for biopsy when evaluating suspicious nodular lesions, particularly those on the trunk and head or neck. Patient education remains critical, according to researchers, not only to discourage tanning behaviors but also to promote self-examination and regular dermatologic evaluation. While thin melanomas are increasingly identified, especially in women, continued vigilance is required for subtypes such as ALM that are not strongly linked to UV exposure and may present atypically.

The study also points to potential disparities in screening behaviors. Men are less likely to attend routine skin checks, a factor that may contribute to delayed NM diagnoses. Targeted outreach and tailored education could help close this gap and reduce mortality associated with late-stage melanoma.

Ultimately, these findings emphasize that subtype, sex, and anatomical site should all be considered in clinical evaluation and public health planning. The decline in superficial spreading melanoma is encouraging and suggests that prevention strategies have had a meaningful impact. However, the recent increase in nodular melanoma in men highlights an urgent need for more focused detection and education efforts. For dermatology clinicians, the data underscore the importance of integrating subtype-specific awareness, risk-tailored counseling, and proactive screening into everyday practice in order to improve melanoma outcomes.

References

1. Alani O, Ahmed A, Haraldsdóttir EL, et al. The incidence and impact of melanoma subtypes in Iceland 1955-2023. Br J Dermatol. 2025. doi:10.1093/bjd/ljaf248
2. Ghiasvand R, Rueegg CS, Weiderpass E, Green AC, Lund E, Veierød MB. Indoor tanning and melanoma risk: Long-term evidence from a prospective population-based cohort study. Am J Epidemiol. 2017;185(3):147-156. doi:10.1093/aje/kww148