Consensus approach to discrepancies arising from independent double reading of screening mammograms

Objective

To establish whether the consensus approach is a reliable method for review of discordant results of double-reported mammograms undertaken through the National Breast Screening Programme at the Norfolk and Norwich University Hospital.

Method

Analysis of a comprehensive database already held of all cancers detected between screening rounds enabled identification of all cancer cases that went through the consensus process and were considered normal. These cases were reviewed to ascertain whether the radiological appearance considered at consensus was actually the site of the subsequently diagnosed cancer.

Results

Over the 6 years of the study three false negative outcomes were identified from 2,264 cases returned to the normal screening round from the consensus process. Out of 1,942 cases that proceeded to assessment through the consensus process, however, 161 cancers were detected, of which 112 had an invasive component. Eighty-three of these cancers were 15 mm or less in size. This left 49 noninvasive (ductal carcinoma in situ) cases, of which 31 were high-grade ductal carcinoma in situ.

Conclusion

These findings illustrate the success of the consensus approach to discordance in screen reading. A combination of two-view mammography and independent double reading has seen an increase in cancer detection.