Trends Of Oral Cavity, Oropharyngeal, And Laryngeal Cancer Incidence In Scotland (1975 - 2012) A Socioeconomic Perspective

Mitana PURKAYASTHA, University of Glasgow Dental School, United Kingdom

1 Department of Community Oral Health, University of Glasgow Dental School, Glasgow, Scotland

Aim: To examine incidence trends of oral cavity (OCC), oropharyngeal (OPC), and laryngeal cancer in Scotland between 1975 and 2012 by socioeconomic status.

Methods:  Our study included all diagnosed cases of OCC (C00.3-C00.9, C02-C06 excluding C2.4), OPC (C01, C2.4, C09-C10, C14), and laryngeal cancer (C32) in the Scottish Cancer Registry (1975-2012). We collated cancer data and corresponding annual midterm population estimates by age, sex, geographic region, and area-based socioeconomic indices (Carstairs91 for 1975-2012 and Scottish Index of Multiple Deprivation SIMD09 for 2001-2012). Age-standardized incidence rates and adjusted Poisson regression rate-ratios (RR) compared subsites by age, sex, region, socioeconomic status, and year of diagnosis.

Results: The fully adjusted Poisson regression model for the whole period (1975-2012) showed that, relative to the least deprived, those living in the most socioeconomically deprived areas had the highest rate-ratios of OCC (RR 2.40; 95% CI 2.18-2.65), OPC (RR 2.49, 95% CI 2.18-2.86), and laryngeal cancer (RR 3.34, 95% CI 3.02-3.69), and an almost dose-like response was observed with increasing deprivation increasing cancer risk. In the most recent decade (2001-2012), incidence rates increased markedly for OPC, decreased for laryngeal cancer and were relatively stable for OCC. Over this period, socioeconomic inequality tended to increase for OPC (RR 3.33; 95% CI 2.72-4.07) and laryngeal cancer (RR 4.98; 95% CI 4.15-5.97) but remained relatively unchanged for OCC (RR 2.69; 95% CI 2.31-3.13). Males exhibited significantly higher rate-ratios across all subsites compared to females. The peak age of incidence of OPC was slightly lower (61-65 years) than the other subsites (71 -75 years).

Conclusion: Contrary to reports that OPC exhibits an inverse socioeconomic profile, our data shows that those from the most relative to the least socioeconomically deprived areas have consistently shown relatively higher rates of head and neck cancer across all subsites.    

Funding Source: NHS Education for Scotland