Benefit of independent double reading in a population-based mammography screening program.

Abstract

To evaluate independent double reading in mammography screening and, specifically, the effect on breast cancer detection. Mammographic studies of 11,343 women, aged 41-75 years, who participated in a population-based screening program were independently screened by two experienced radiologists. A retrospective analysis also was performed from notations made for patient recalls. Including follow-up of recalled women, 131 surgical biopsies were performed, which resulted in 76 histologically proved breast cancers. Fifty-six cancerous lesions were detected by both screeners. One screener detected 14 cancerous lesions alone, and the other detected six alone. Of the cancerous lesions detected by only one screener, 85% were stage 0 or 1, compared with 59% of those detected by both screeners. Double reading detected 15% (95% confidence interval, +/- 7%) more cancer cases with an almost unchanged positive predictive value of 0.6. Independent double reading does significantly increase sensitivity of mammography screening.