Dermatology Online Journal

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 a LMM after LM. Data on newly diagnosed LM and LMM were obtained from the Netherlands Cancer Registry and PALGA (Dutch Pathology Database). Age-standardized incidence rates (European standardized rate [ESR]), estimated annual percentage changes (EAPC), and the cumulative incidence of LMM after LM were calculated. Between 1989-2013, 10,545 patients were diagnosed with a primary LM and 2,898 with a primary LMM in the Netherlands. The ESR for LM increased from 0.72 to 3.84 per 100,000 person-years, and for LMM from 0.24 to 1.19 between 1989-2013. LM incidence increased from 2002-2013 with 6.8% annually, prior to the – even steeper – rise in LMM incidence from 2007-2013 (EAPC: 12.4%). The cumulative incidence of LMM after a primary LM after 25 years 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, increased histological confirmation, diagnostic drift and changed market forces, to reflect a true increase. The absolute risk of a LMM (at any location) after a histologically confirmed LM was low (2.0 – 2.6%).