Epidemiology of Lentigo Maligna and Lentigo Maligna Melanoma in the Netherlands, 1989-2013.

Lentigo maligna (LM) is considered a precursor to LM melanoma (LMM). We assessed trends in LM and LMM incidence rates between 1989 and 2013 in the Netherlands, and estimated the risk of an LMM after LM. Data on newly diagnosed LM and LMM were obtained from the Netherlands Cancer Registry and PALGA: Dutch Pathology Registry. Age-standardized incidence rates (European standardized rate), estimated annual percentage changes, and the cumulative incidence of LMM after LM were calculated. Between 1989 and 2013, 10,545 patients were diagnosed with a primary LM and 2,898 with a primary LMM in the Netherlands. The age-standardized incidence rate for LM increased from 0.72 to 3.84 per 100,000 person-years, and for LMM from 0.24 to 1.19 between 1989 and 2013. LM incidence increased from 2002 to 2013 with 6.8% annually, before an even steeper rise in LMM incidence from 2007 to 2013 (estimated annual percentage change: 12.4%). The cumulative incidence of LMM after a primary LM after 25-year follow-up was 2.0% for males and 2.6% for females. The increased incidence of LM and LMM in the Netherlands seems, besides increased awareness and increased histological confirmation of LM, to reflect a true increase. The absolute risk of an LMM (at any location) after a histologically confirmed LM was low (2.0-2.6%).