Previous epidemiology reviews of exposure to
styrene and the risk of
cancer considered studies published through 13 November 2013. Since then, additional relevant research has been published. No review has included meta-analyses. The current systematic review considered research published through June 2017; included meta-analyses of the relationship between any exposure to
styrene and
cancers identified as being of concern, including
non-Hodgkin lymphoma (NHL),
leukemia and
cancers of the esophagus, pancreas, lung and kidney; and evaluated several other forms of
cancer. Meta-relative risks for all studies were 1.14 (95% confidence interval (CI), 0.91-1.43) for NHL, 1.00 (95% CI, 0.80-1.26) for
multiple myeloma, 0.98 (95% CI, 0.87-1.09) for all
leukemia, 1.03 (95% CI, 0.92-1.15) for
esophageal cancer, 1.02 (95% CI, 0.93-1.12) for
pancreatic cancer, 1.09 (95% CI, 0.95-1.24) for
lung cancer and 1.10 (95% CI, 0.99-1.22) for
kidney cancer. Individual studies provided little evidence of exposure-response or induction time trends. Limitations of the available research and of the meta-analyses included reliance in most studies on mortality data rather than on incidence data, lack of quantitative estimates of
styrene exposure for individual subjects and lack of information on lifestyle factors. Consideration of all pertinent data, including substantial recent research, indicates that the epidemiologic evidence on the potential carcinogenicity of
styrene is inconclusive and does not establish that
styrene causes any form of
cancer in humans.