Systematic review and meta-analysis of prognostic characteristics for breast cancers in populations with digital vs film mammography indicate the transition may have increased both early detection and overdiagnosis

Rachel Farber; Michael L Marinovich; Audrey Pinna; Nehmat Houssami; Kevin McGeechan; Alexandra Barratt; Katy J L Bell

doi:10.1016/j.jclinepi.2024.111339

Systematic review and meta-analysis of prognostic characteristics for breast cancers in populations with digital vs film mammography indicate the transition may have increased both early detection and overdiagnosis

J Clin Epidemiol. 2024 Apr 2:171:111339. doi: 10.1016/j.jclinepi.2024.111339. Online ahead of print.

Authors

Rachel Farber¹, Michael L Marinovich², Audrey Pinna³, Nehmat Houssami⁴, Kevin McGeechan¹, Alexandra Barratt¹, Katy J L Bell⁵

Affiliations

¹ Faculty of Medicine and Health, Sydney School of Public Health, The University of Sydney, Sydney 2006, Australia.
² The Daffodil Centre, The University of Sydney, A Joint Venture with Cancer Council NSW, Sydney 2006, Australia.
³ Faculty of Medicine and Health, Sydney School of Public Health, The University of Sydney, Sydney 2006, Australia; Department of medical imaging, Flinders Medical Centre, Adelaide, South Australia, Australia.
⁴ Faculty of Medicine and Health, Sydney School of Public Health, The University of Sydney, Sydney 2006, Australia; The Daffodil Centre, The University of Sydney, A Joint Venture with Cancer Council NSW, Sydney 2006, Australia.
⁵ Faculty of Medicine and Health, Sydney School of Public Health, The University of Sydney, Sydney 2006, Australia. Electronic address: katy.bell@sydney.edu.au.

PMID: 38570078
DOI: 10.1016/j.jclinepi.2024.111339

Abstract

Objectives: Film mammography has been replaced by digital mammography in breast screening programs globally. This led to a small increase in the rate of detection, but whether the detection of clinically important cancers increased is uncertain. We aimed to assess the impact on tumor characteristics of screen-detected and interval breast cancers.

Study design and setting: We searched seven databases from inception to October 08, 2023, for publications comparing film and digital mammography within the same population of asymptomatic women at population (average) risk of breast cancer. We recorded reported tumor characteristics and assessed risk of bias using the Risk Of Bias In Non-randomised Studies - of Interventions tool. We synthesized results using meta-analyses of random effects.

Results: Eighteen studies were included in the analysis from 8 countries, including 11,592,225 screening examinations (8,117,781 film; 3,474,444 digital). There were no differences in tumor size, morphology, grade, node status, receptor status, or stage in the pooled differences for screen-detected and interval invasive cancer tumor characteristics. There were statistically significant increases in screen-detected ductal carcinoma in situ (DCIS) across all grades: 0.05 (0.00-0.11), 0.14 (0.05-0.22), and 0.19 (0.05-0.33) per 1000 screens for low, intermediate, and high-grade DCIS, respectively. There were similar (non-statistically significant) increases in screen-detected invasive cancer across all grades.

Conclusion: The increased detection of all grades of DCIS and invasive cancer may indicate both increased early detection of more aggressive disease and increased overdiagnosis.

Keywords: Cancer; Digital; Ductal carcinoma in situ; Film screen; Health outcomes; Interval cancer; Mammography; Recall; Tumor characteristics.