Oral cancer in the North-East of England: incidence, mortality trends and the link with material deprivation.

This study set out to determine the incidence of, and mortality from, oral cancer in the North-East of England between the mid-1970s and the early 1990s; to investigate its relation to material deprivation; and to test the completeness of cancer registry data. The Northern Region Cancer Registry provided details of registrations, deaths and population estimates. For analyses by deprivation, Small Area Statistics were obtained from the 1981 and 1991 censuses. In a selected sample district, 100% completeness and 89% accuracy of cancer registration of these conditions were found. For both tongue and mouth cancer, age- and sex-specific incidence and mortality rates rose with age and there was little change with time. When age-standardised registration and mortality ratios were compared between the Northern Region and England & Wales, only those for mouth cancer in males were significantly different. Crude survival from cancer of the tongue in males improved in the Northern Region from 1971-74 to 1983-86 but there was no improvement in females nor for cancer of the mouth in both sexes. In males for both tongue and mouth cancer, there was a graded increase in the standardised registration and mortality ratios from the most affluent to the most deprived areas but these differences were less marked in females. These differences in mouth cancer incidence found between England & Wales and the Northern Region probably reflect differences in lifestyles. The North ranks worst among the regions of England & Wales on a number of criteria of material deprivation, and long-term unemployment is one of the highest in the country. The analysis by deprivation has shown a clear relation to material deprivation. Whether socio-economic deprivation per se or a different risk factor behaviour associated with deprivation (smoking, alcohol consumption, poor diet) is the cause of these differences is not known. However, it is very likely that different risk factor behaviour plays a major part.