Effectiveness of a small breast screening programme: 25 year evaluation (25 year breast screening evaluation)

Area of Science:

• Public Health
• Oncology
• Radiology

Background:

• Mammography screening programs aim to reduce breast cancer mortality.
• Quality control is crucial for effective screening, especially in smaller populations.
• Jersey's breast screening program operated over 25 years (1990-2015) for women aged 50-75 with biennial screening.

Purpose of the Study:

• To evaluate the quality and effectiveness of mammography screening on the Island of Jersey over a 25-year period.
• To assess key performance indicators and their impact on breast cancer mortality reduction.
• To determine if a small screening program can achieve national standards.

Main Methods:

• Analysis of routinely collected data on screening uptake, recall rates, screen-detected cancers, and interval cancers.
• Assessment of cancer grade, stage, and comparative mortality rates.
• Calculation of standardized detection ratio (SDR) and estimated mortality reduction.

Main Results:

• Screening uptake was 85.2% (16,866 of 19,768 invited).
• 501 screen-detected cancers (400 invasive, 101 DCIS) and 125 interval cancers were recorded.
• Annual recall rates were consistently below 6% (prevalent) and 4% (incident).
• Estimated breast cancer mortality reduction was 40.2% based on SDR and uptake.

Conclusions:

• Despite its small population, Jersey's program achieved detection rates comparable to the UK NHS Breast Screening Programme.
• Rigorous quality control and continuous monitoring of key metrics are vital for small screening units.
• High survival rates (>90% 10-year survival for screen-detected invasive cancers) and the need for vigilance with interval cancers were noted.
• Lapsed attenders' mortality suggests potential benefits from extending the screening age range.