RF03 Lentigo maligna 2013–2019 in England: incidence and survival of 18,377 cases

Abstract

Abstract Lentigo maligna (LM) is a common melanoma in situ with limited national epidemiological data. National data on LM incidence, age groups and 5-year survival in England from 2013 to 2019 were explored using report-level data published openly on the ‘Get Data Out’ National Disease Registration Service (NDRS) programme. In total, 18 377 new cases (49% male, 51% female) of LM were registered in England, with a mean of 2625 new diagnoses per year. The crude incidence rate of LM increased from 4.33/100 000 [95% confidence interval (CI) 4.16–4.51] in 2013 to 4.69/100 000 (95% CI 4.52–4.87) in 2019. The average crude incidence rate of LM per year was 23.4/100 000 [95% CI 22.7–24.9; 35.2 male (95% CI 33.2–37.4), 15.4 female (95% CI 15.2–17.5)] in those aged > 80 years vs. 0.59/100 000 [95% CI 0.55–0.62; 0.65 male (95% CI 0.59–0.71), 0.53 female (95% CI 0.47–0.59)] in those aged < 60 years. Overall, 5-year Kaplan–Meier survival was 83.1% (95% CI 81.5–84.6) for LM diagnosed in 2013, while 5-year overall net survival was 103.7% (95% CI 101.2–106.2) in 2014. By comparison, for invasive melanoma, 5-year overall Kaplan–Meier survival was 79.1% (95% CI 78.3–79.8) and 5-year overall net survival was 88.6% (95% CI 87.6–89.6) for 2013 diagnoses. Important limitations are that registered LM is based on histopathological data or multidisciplinary team discussions; hence, LM treated topically without biopsy or untreated LM were not included. Privately treated patients were also under-represented, as there was no requirement for private laboratory data to be submitted to NDRS, unlike data from National Health Service laboratories. The apparent 5-year LM-specific survival advantage is likely due to fewer frail patients seeking medical attention, being referred or undergoing histological confirmation. We report the largest series of data on LM in Europe to date. The observed increase in the incidence of LM and its excellent 5-year net survival supports further discussion on current clinical practice and treatment options.