Abstract 1875: Lung cancer risk among hairdressers in SYNERGY – pooled analysis from case-control studies in Europe and Canada with detailed smoking data

Abstract

Abstract “Occupational exposure as a hairdresser or barber” was classified as probably carcinogenic to humans by the International Agency for Research on Cancer in volume 99 (2010). Small increases in lung cancer risk (20-40%) are found in most cohort studies but without adequate adjustment for smoking. Studies in Scandinavia and the USA show a higher prevalence of smokers among hairdressers than in the general population. The SYNERGY project has pooled information on lifetime work histories (ISCO-68) and tobacco smoking from 13479 cases and 16350 controls, including 20% women, from 11 case-control studies in 12 European countries and Canada. The original studies were conducted between 1985 and 2005. Odds ratios (OR) for lung cancer and 95% confidence intervals (CI) were estimated by unconditional logistic regression, adjusted for age, sex, study, cigarette pack-years and time since quitting smoking. Less than 1% of the study population had ever worked as hairdresser or barber (0.89% of cases and 0.74% of controls). Hairdressers and barbers experienced a slight increase in lung cancer risk OR 1.16 (95%CI 0.90-1.49), which disappeared after adjusting for smoking OR 0.97 (95%CI 0.73-1.30). Results by duration of employment showed highest risks in hairdressers with short employment. Results were similar by gender, histology of lung cancer, and for women hairdressers. We observed a slight and non-significant increase in risk for male barbers, particularly in barbers with the longest employment and after adjustment for smoking. We could not detect an association between having worked as hairdresser or barber and increased lung cancer risk overall after adjusting for smoking. However, among male barbers we observed an increasing risk with increasing duration, although non-significant, after adjusting for tobacco smoking. Final results will include several more studies, and thereby increase the precision of our effect estimates. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1875. doi:10.1158/1538-7445.AM2011-1875