Are there socioeconomic gradients in stage and grade of breast cancer at diagnosis? Cross sectional analysis of UK cancer registry data

Further data on women exposed or not exposed to national screening programme

Table

Further data on women exposed or not exposed to national screening programme

If our hypothesis that socioeconomic variations in uptake of screening have led to socioeconomic variations in disease progression at diagnosis is correct, we would expect that the effect of socioeconomic position on markers of disease progression at diagnosis would be stronger in those age groups eligible for breast cancer screening. The national breast cancer screening programme invites all women aged 50-74 for triennial mammography. The programme was initiated in 1988. We can therefore assume that women aged 75 or above or less than 50 in 1998-2000 would not have been eligible for breast cancer screening. Those aged between 50 and 74 in 1998-2000 would have been eligible for breast cancer screening at some point. Although not all breast cancers in this second group will have been identified by the breast cancer screening programme, exposure to the programme may increase knowledge and awareness of breast cancer and, therefore, may have some effect beyond the time period when it is actively offered.

The odds of women being diagnosed with advanced stage or high grade of disease according to eligibility for the national breast cancer screening programme are shown in the extra table. As expected, socioeconomic position had a stronger effect on disease progression in those women potentially exposed to breast cancer screening.

Table Odds ratios with tests for trend of odds of advanced stage or high grade of breast cancer at diagnosis by fifths of Townsend deprivation score (TDS) according to eligibility for national breast cancer screening programme

*Aged <50 or ³ 75 at diagnosis.

†Aged 50-74 at diagnosis.