Screening outcomes by risk factor and age: evidence from BreastScreen WA for discussions of risk‐stratified population screening

• Published in: Medical journal of Australia 2021-10, Vol.215 (8), p.359-365
• Main Authors: Noguchi, Naomi, Marinovich, Michael L, Wylie, Elizabeth J, Lund, Helen G, Houssami, Nehmat
• Format: Article
• Language: English
• Subjects: Adult; Age Factors; Aged; Breast neoplasms; Breast Neoplasms - diagnostic imaging; Breast Neoplasms - epidemiology; Cohort Studies; Diagnostic Techniques and Procedures; Early Detection of Cancer; Environment and Public Health; Epidemiology; Epidemiology and Research Design; Female; Humans; Mammography; Mass screening; Middle Aged; Neoplasms; Population health; Research and Reviews; Retrospective Studies; Risk Assessment; Risk Factors; Self Report; Statistics
• ISSN: 0025-729X; 1326-5377
• DOI: 10.5694/mja2.51216

Objectives To estimate rates of screen‐detected and interval breast cancers, stratified by risk factor, to inform discussions of risk‐stratified population screening. Design Retrospective population‐based cohort study; analysis of routinely collected BreastScreen WA program clinical and administrative data. Setting, participants All BreastScreen WA mammography screening episodes for women aged 40 years or more during 1 July 2007 ‒ 30 June 2017. Main outcome measures Cancer detection rate (CDR) and interval cancer rate (ICR), by risk factor. Results A total of 323 082 women were screened in 1 026 137 screening episodes (mean age, 58.5 years; SD, 8.6 years). The overall CDR was 68 (95% CI, 67‒70) cancers per 10 000 screens, and the overall ICR was 9.7 (95% CI, 9.2‒10.1) cancers per 10 000 women‐years. Interactions between the effects on CDR of age group and five risk factors were statistically significant: personal history of breast cancer (P = 0.039), family history of breast cancer (P = 0.005), risk‐relevant benign conditions (P = 0.012), hormone‐replacement therapy (P = 0.002), and self‐reported symptoms (P