Socio-economic status and head and neck cancer incidence in the Nordic countries

Background: The impact of societal factors on the occurrence of head and neck cancers (HNCs) remains understudied, especially in the Nordic countries. Methods: To quantify the association between socio-economic status (SES) and the occurrence of HNCs, this cohort study uses data from the Nordic Occupational Cancer project that combine occupational and cancer registry data from 1961 to 2005 of 14.9 million individuals aged between 30 and 64 years. Occupational categories were combined into seven socio-economic categories. Standardized incidence ratio (SIR) analyses were conducted with the cancer incidence rates for the entire national study populations used as reference rates. Results: Altogether, 83 997 HNCs - 72% in men and 28% in women - were recorded. Among men, a gradient of risk associated with SES was observed for cancers of the tongue, other oral cavity subsites, pharynx, oropharynx and larynx in groups with lower SES. Managers showed decreased SIRs of 0.50 to -0.90 also for cancers of the lip, tongue, other oral cavity subsites, oropharynx, nasopharynx, nose and larynx. In contrast, excess risks of tongue, other oral cavity subsites, pharyngeal, oropharyngeal and laryngeal cancers were observed among clerical (SIRs 1.05-1.16), skilled workers (1.04-1.14), unskilled workers (1.16-1.26) and economically inactive men (1.38-1.87). Among women, no risk gradient similar to that in men was revealed. Conclusions: The current study underscores the influence of SES on the incidence of HNCs and highlights the need for targeted interventions, including tobacco and alcohol control policies, and improved access to healthcare services, particularly for socio-economically disadvantaged populations.