Background
The organised, population-based Slovenian breast cancer screening programme began providing biennial mammography for women aged 50-69 in 2008, roll-out was completed in 2019. The programme has taken a comprehensive approach to quality assurance as recommended by the European guidelines, including national breast cancer screening policy, centralized management, assessment, training and supervision, regular quality assurance and monitoring of performance indicators.
 
Objectives
The strategic objective of the screening programme is to reduce breast cancer mortality in the target population by 25–30%, which can only be achieved with high participation and by ensuring high quality at every stage of the screening pathway. This publication aims to present the results of the programme, focusing on key performance and surrogate indicators, together with an European comparative context.
Methods
The programme strictly adheres to the European Guidelines for Quality Assurance in Breast Cancer Screening and Diagnosis and European Commision Initiative on Breast Cancer. All screening centres are required to perform the programme uniformly in accordance with the professional standards of the programme, defined in the National Programme Guidelines. The results presented for the period 2008-2025 are retrieved from the national breast cancer screening registry and Slovenian cancer registry.

Results
Over the first 17 years of the programme, 420,000 women were invited to mammography screening, 1,067,620 mammographies were performed, and 6,300 women have been diagnosed with breast cancer. The average participation rate was 76%. In 2024, invitation and screening coverage were 98% and 77%, respectively. Mammography sensitivity and specificity exceeded 80% and 95% each year.
In the screening, 70% of detected breast cancers are non-invasive or stage I, and 40% of detected invasive cancers measure 10 mm or less. Breast cancers detected through screening are clinically and statistically significantly more often diagnosed at lower stages compared to cancers diagnosed in women of the same age outside the screening. Since the introduction of the programme, there has been a population-level increase in localized-stage breast cancer diagnoses and a decrease in advanced-stage cases. With a 78% participation rate in 2022, Slovenia ranks fourth in the Europe; EU – 24 countries average in 2022 was 56%. In 2024, European Cancer Screening Policy Index ranked Slovenia’s screening policy (including breast, cervical, and colorectal cancer screening) first among all European countries. Also, Slovenia serves as an example of good practice and a training hub for countries that are still establishing screening programmes.

Conclusions
Slovenian breast cancer screening programme is one of the most successful in the Europe, ensuring equitable access to timely, high-quality screening and treatment for all women in the target population. It is a highly professional and women-centered programme that maintains high public trust and participation. Consistent adherence to European quality indicators, verified through annual monitoring and rigorous quality assurance, ensures population-level effectiveness and a long-term reduction in the breast cancer mortality. Programme’s future activities will focus on maintaining high quality throughout the screening pathway, following new evidence-based recommendations, and preparing for the age expansion to 45–74 years.