The clinical and pathological differences in prevalent round screen-detected and symptomatic invasive breast cancer.

The potential benefits of breast cancer screening include the detection of cancers at a more favourable stage, however, cancers detected during the prevalent round of screening may differ from true screen-detected cancers. These differences are poorly defined. This study prospectively assessed all women between 50 and 64 years of age undergoing curative surgery for breast cancer, both screen-detected and symptomatic, in one screening centre during the prevalent round of the national breast cancer-screening programme. Four hundred and thirty seven patients (364 screen-detected and 73 symptomatic patients) underwent surgery for breast cancer. Symptomatic breast cancers were of a higher grade (p < 0.0001; Chi2) and less likely to be oestrogen receptor positive (49% versus 88%; p < 0.0001; Fisher's exact test); however there was no difference in size of tumour or axillary nodal positivity. This study suggests that tumours detected by screening during the prevalent round of a screening programme are of a more prognostically favourable type than symptomatic breast cancers in the same age group.