The impact of socio-economic circumstances on overall and grade-specific prostate cancer incidence: a population-based study

BACKGROUND: If the observed increasing incidence of prostate cancer and higher incidence in more affluent men are due to differences in diagnostic sensitivity, an excess of asymptomatic low-grade tumours might be expected. METHODS: We conducted a descriptive population-based study of incident cases of prostate cancer (International Classification of Diseases version 10 codes for prostate cancer) in the West of Scotland, using the Scottish Cancer Registry data from 1991 to 2007. Socio-economic circumstances were measured using the Carstairs score, and disease grade measured using the Gleason score. Deprivation-specific European age-standardised incidence rates were calculated, and joinpoint regression analysis were used to identify significant changes in trends over time. RESULTS: A total of 15 519 incident cases of prostate cancer were diagnosed. Incidence increased by 70% from 44 to 75 per 100 000 cases between 1991 and 2007, an average annual growth of 3.6%. Men aged <65 years experienced the largest increase in incidence. A widening socio-economic deprivation gap in incidence appeared from 1998 onwards in low-grade disease only. From 2003 to 2007, the deprivation gap (affluent to deprived) was 40.3 per 100 000 cases (P<0.001; trend), with rates 37% lower among the most deprived compared with the most affluent. This deprivation gap represents an estimated 1764 cases of prostate cancer over a 5-year period. CONCLUSION: Prostate cancer incidence continues to increase; an increase in low-grade disease in affluent men may suggest that prostate-specific antigen testing is responsible, but it does not explain the overall increases in all grades of disease.