Socioeconomic status and head and neck cancer.
METHODS
This was a population-based case-control study. CASE-CONTROL SELECTION: Eligible patients were aged between 18 and 80 years and had a primary histopathological diagnosis made between April 2002 and December 2004. Diagnosis included malignant cancers of the oral cavity, oropharynx, hypopharynx or larynx. Incident cases were identified through weekly monitoring of head and neck cancer clinics in hospital departments and were confirmed by pathology department records. Controls matched by age (5-year age band) and sex were randomly selected from the lists of general practitioners.


METHODS
Information about occupation, education, smoking and alcohol consumption was collected at personal interview. Socioeconomic circumstances were measured at an individual level (education, occupational social class, unemployment), and by area-based measures of deprivation. Odds ratios (OR) and corresponding 95% confidence intervals (CI) were computed by unconditional logistic regression and were adjusted for age and sex. This model was repeated to assess for potential independent effects of the range of socioeconomic components after adjusting for smoking and alcohol consumption. Interactions between smoking and consumption of alcohol, and between individual and area-based measures for socioeconomic factors were tested by the likelihood ratio test. In addition, the most important behavioural risk factors and socioeconomic variables were entered into a stepwise multivariate logistic regression model. All statistical analyses were carried out using Statistical Analysis System (SAS; Cary, North Carolina, USA) software.


RESULTS
The study population included 103 cancer patients (38 women and 65 men), and 91 controls (39 women and 52 men). Individuals living in the most deprived areas (OR, 4.66; 95% CI, 1.79- 12.18) and those who were unemployed (OR, 2.27; 95% CI, 1.21- 4.26) had a significantly higher risk of cancer than people who had high levels of educational attainment (OR, 0.17; 95% CI, 0.05-0.58). Significance was lost for all measures of social class when adjustments were made for smoking and consumption of alcohol. When the most important behavioural and socioeconomic factors were combined in a fully adjusted multivariate analysis, smoking was the only significant risk factor (OR, 15.53; 95% CI, 5.36-44.99) found to be independently associated with head and neck cancers.


CONCLUSIONS
A high risk of head and neck cancer was consistently associated with poor socioeconomic circumstances. There were strong links for specific components but smoking dominated the overall profile of risk. More detailed research into the nature of such associations is needed in the future.
Al-Dakkak
Imad
I
Centre for Evidence-based Dentistry, Oxford, UK.