Background: Cancer incidence varies by socioeconomic group and these variations have been linked with environmental and lifestyle factors, differences in access to health care and health seeking behaviour. Socioeconomic variations in cancer incidence by region and age are less clearly understood but they are crucial for targeting prevention measures and health care commissioning.
Methods: Data were obtained from all eight English cancer registries for patients diagnosed between 1998 and 2003, for all invasive cases of female breast cancer (ICD-10 code C50), lung cancer (ICD-10 codes C33-C34), cervical cancer (ICD-10 code C53), and malignant melanoma of the skin (ICD-10 code C43). Socioeconomic status was assigned to each patient based on their postcode of residence at diagnosis, using the income domain of the Index of Multiple Deprivation 2004. We analysed the socioeconomic variations in the incidence of breast, lung and cervical cancer and malignant melanoma of the skin for England, and regionally and by age.
Results: Incidence was highest for the most deprived patients for lung cancer and cervical cancer, whilst the opposite was observed for malignant melanoma and breast cancer. The difference in incidence between the most and the least deprived groups was higher for lung cancer patients aged under 65 at diagnosis than those over 65 at diagnosis, which may indicate a cohort effect. There were regional differences in the socioeconomic gradients with the gap being widest for lung and cervical cancer in the North (North East, North West and Yorkshire and Humberside) and for malignant melanoma in the East and South West. There were only modest variations in breast cancer incidence by region. If the incidence of lung and cervical cancer were decreased to that of the least deprived group it would prevent 36% of lung cancer cases in men, 38% of lung cancer cases in women and 28% of cervical cancer cases. Incidence of breast cancer and melanoma was highest in the least deprived group, therefore if all socioeconomic groups had incidence rates similar to the least deprived group it is estimated that the number of cases would increase by 7% for breast cancer, 27% for melanoma in men and 29% for melanoma in women.
Conclusion: National comparison of socioeconomic variations in cancer incidence by region and age can provide an unbiased basis for public health prevention and health commissioning. Decreasing inequalities in incidence requires the integration of information on risk factors, incidence and projected incidence but targeted public health interventions could help to reduce regional inequalities in incidence and reduce the future cancer burden.