Life course social mobility and risk of upper aerodigestive tract cancer in men.

The aim of this study was to explore associations between social mobility and tumours of the upper aero-digestive tract (UADT), focussing on life-course transitions in social prestige (SP) based on occupational history. 1,796 cases diagnosed between 1993 and 2005 in ten European countries were compared with 1585 controls. SP was classified by the Standard International Occupational Prestige Scale (SIOPS) based on job histories. SIOPS was categorised in high (H), medium (M) and low (L). Time weighted average achieved and transitions between SP with nine trajectories: H --> H, H --> M, H --> L, M --> H, M --> M, M --> L, L --> H, L --> M and L --> L were analysed. Odds ratios (ORs) and 95%-confidence intervals [95%-CIs] were estimated with logistic regression models including age, consumption of fruits/vegetables, study centre, smoking and alcohol consumption. The adjusted OR for the lowest versus the highest of three categories (time weighted average of SP) was 1.28 [1.04-1.56]. The distance of SP widened between cases and controls during working life. The downward trajectory H --> L gave an OR of 1.71 [0.75-3.87] as compared to H --> H. Subjects with M --> M and L --> L trajectories ORs were also elevated relative to subjects with H --> H trajectories. The association between SP and UADT is not fully explained by confounding factors. Downward social trajectory during the life course may be an independent risk factor for UADT cancers.