A LARGE population-based study from England suggests that lentigo maligna (LM) carries a very low long-term risk of progressing to invasive lentigo maligna melanoma (LMM), supporting more individualised treatment discussions in older and frailer patients.
The study analysed national cancer registration data from England between 2013 and 2023 to investigate incidence trends, survival outcomes, and progression rates for LM and LMM. Researchers examined pseudonymised records provided by the National Disease Registration Service, making this one of the largest contemporary studies of these melanoma subtypes.
LM is a melanoma in situ that typically develops on chronically sun-exposed skin, particularly in older adults. Although surgical excision is commonly recommended, evidence regarding the natural history of untreated disease has remained limited.
The investigators found that age-standardised incidence rates for both LM and LMM remained broadly stable between 2013 and 2019. However, diagnoses fell during 2020, likely reflecting disruption to healthcare access during the COVID-19 pandemic, before rising again by 2023 to levels exceeding those seen before the pandemic.
Only 1% of Lentigo Maligna Cases Progressed Over 10 Years
Importantly, the risk of progression from LM to invasive LMM was low. Using matched tumour sites and defined latency periods, the researchers estimated a cumulative progression risk of 1.0% at 10 years. Progression risk increased with advancing age and was higher for lesions located on the head and neck.
Survival outcomes were generally favourable. Patients with LM and LMM were more likely to die from cardiovascular disease or other cancers than from melanoma itself. Female sex was associated with a significantly lower melanoma-specific mortality risk, while increasing age was linked to poorer outcomes.
Researchers Call for Further Evidence on Untreated LM Progression
The authors suggest these findings may have important implications for clinical decision-making, particularly in elderly patients with significant comorbidity. Given the excellent overall and melanoma-specific survival observed in LM, alongside the low risk of progression, the study supports patient-centred management discussions that carefully balance treatment burden against likely benefit.
However, the researchers caution that further evidence is needed to better understand the true risk of progression in untreated LM. They also note that ongoing surveillance of incidence trends will be important to determine whether the post-pandemic rise in diagnoses reflects delayed presentation or a genuine increase in disease burden.
Reference
Karponis D et al. Epidemiology of lentigo maligna and lentigo maligna melanoma in England between 2013–2023. Br J Dermatol. 2026;DOI: 10.1093/bjd/ljag177.
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