Iceland The Icelandic LC study has been described previously.2 The primary source of information on the Icelandic LC cases is the Icelandic Cancer Registry, which covers the entire population of Iceland (http://www.cancerregistry.is). Briefly, according to the Icelandic Cancer Registry, a total of 4560 LC patients were diagnosed from 1 January 1955 to 31 December 2012. Recruitment of both prevalent and incident cases was initiated in 1998, the recruitment is ongoing and DNA samples from LC cases were subjected to whole-genome genotyping as they are collected. The LC associations were based on 1437 chip-typed LC cases (median age 70 years, range 16–97, 48% males) and 84 086 chip-typed controls in addition to 2572 LC cases and 137 443 controls who had at least one of their first- or second-degree relatives chip-typed. To study early-onset LC we considered subjects diagnosed before reaching an age of 58 years.
