LeMasters 2006: Meta-analysis of 28 cohort and case-control studies. IARC 2010: Updated meta-analyse, two new large studies, focus on four candidate cancers identified by LeMasters. NOCCA (Pukkala) 2014: Chort study, 16 000 professional firefighters followed for cancer incidence 1960-2005: 2 536 cancers. Daniels 2014: Cohort study, 30 000 professional firefighters in two North American cities, followed 1985-2009: 4 461 cancers. Glass 2015: Cohort study, 17 000 Australian full-time professional firefighters, followed 1990-2011: 1 208 cancers. Daniels 2015: Case-control study with 1 333 deaths from cancer in three major US cities.