Impact of the second reader on screening outcome at blinded double reading of digital screening mammograms

Angela M P Coolen,Vivianne C G Tjan-Heijnen,Luc J Strobbe,Adri C Voogd,Lucien E M Duijm,Marieke W J Louwman

doi:10.1038/s41416-018-0195-6

Abstract

BackgroundTo determine the impact of the second reader on screening outcome at blinded double reading of digital screening mammograms.MethodsWe included a consecutive series of 99,013 digital screening mammograms, obtained between July 2013 and January 2015 and double read in a blinded fashion. During 2-year follow-up, we collected radiology, surgery and pathology reports of recalled women.ResultsSingle reading resulted in 2928 recalls and 616 screen-detected cancers (SDCs). The second reader recalled another 612 women, resulting in 82 additional SDCs. Addition of the second reader increased the recall rate (3.0% to 3.6%, p < 0.001), cancer detection rate (6.2–7.0 per 1000 screens, p < 0.001) and false positive recall rate (24.4–28.7 per 1000 screens, p < 0.001). Positive predictive value of recall (21.0% vs. 19.7%, p = 0.20) and of biopsy (52.1% vs. 50.9%, p = 0.56) were comparable for single reading and blinded double reading. Tumour characteristics were comparable for cancers detected by the first reader and cancers additionally detected by the second reader, except of a more favourable tumour grade in the latter group.ConclusionsAt blinded double reading, the second reader significantly increases the cancer detection rate, at the expense of an increased recall rate and false positive recall rate.

Highlights

The first regional and nationwide breast cancer screening programmes were implemented in the 1980’s.1 These screening programmes aimed to reduce breast cancer mortality through detection and treatment of breast malignancies at an early stage.In the Netherlands, the nationwide biennial breast cancer screening programme was gradually implemented from 1989 through 1997.2 Years later screen-film mammography (SFM) was replaced by full-field digital mammography (FFDM), significantly enhancing the cancer detection rate (CDR).[3,4] In our screening region, the transition to FFDM was completed in 2010
Breast cancer was diagnosed in 704 women, resulting in an overall CDR of 7.1 per 1000 screens and a positive predictive value (PPV) of recall of 19.8% (Fig. 1)
Twenty-two women were recalled after reassessment of positive mammographer findings, resulting in six additional screen-detected cancers

Summary

Introduction

The first regional and nationwide breast cancer screening programmes were implemented in the 1980’s.1. In the Netherlands, the nationwide biennial breast cancer screening programme was gradually implemented from 1989 through 1997.2 Years later screen-film mammography (SFM) was replaced by full-field digital mammography (FFDM), significantly enhancing the cancer detection rate (CDR).[3,4] In our screening region, the transition to FFDM was completed in 2010. To determine the impact of the second reader on screening outcome at blinded double reading of digital screening mammograms. CONCLUSIONS: At blinded double reading, the second reader significantly increases the cancer detection rate, at the expense of an increased recall rate and false positive recall rate

Methods

Results

Conclusion