A comparison of invasive breast cancer detected in a screened population with invasive breast cancers detected at rapid access diagnostic facilities.

The objective of this study was to assess the impact of rapid access breast diagnostic facilities on the benefit of mammographic breast screening. Invasive cancers were compared for maximum diameter in two groups: group A--70 patients, with screen detected breast cancer aged 50-65, mean age 55.8; group B--46 patients, with symptomatic breast cancer aged 50-65, mean age 56.7. Group A patients had all been invited for screening and included interval cancers and cancers in lapsed attenders. Group B patients were detected at rapid access diagnostic facilities. In group A (screened) the invasive cancers had a mean diameter of 17.8 mm, with a median of 15 mm. Group B (unscreened) consisted of invasive cancers with a mean diameter of 25.2 mm, and a median of 25 mm. Thirty-two (46%) of the screened cancers were found to be less than 15 mm compared to 5 (11%) of the unscreened cancers, using the Wilcoxon Rank Sum Test, P<0.001. Although rapid access modern diagnostic facilities for breast cancers offer the ability to detect early cancers (11% in this survey), screen detected invasive cancers remain significantly smaller even when interval cancers and cancers in lapsed attenders are included.