Breast Cancer Screening Program Fails to Increase Participation as Expected

In 2014, Austria introduced a quality-assured breast cancer screening program aimed at inviting women to participate in early detection efforts. The intention was to facilitate the discovery of mammary carcinomas at earlier stages. However, a recent study conducted in Salzburg raises serious doubts about the program's effectiveness.

The findings suggest that there has been no significant improvement in breast cancer detection compared to the period before the program's implementation. Researchers, including Simon Gampenrieder from the University Clinic for Internal Medicine III in Salzburg, alongside prominent oncologist Richard Greil, reported that their results do not support the assumption that the introduction of the national breast cancer screening program in Austria has significantly reduced the incidence of advanced breast cancer stages in Salzburg.

These conclusions apply at the population level, indicating that while it is crucial for women--ideally between the ages of 45 and 74--to undergo regular screenings to mitigate their personal risk for advanced mammary carcinoma, the broader implications of the study are alarming. Annually, approximately 5,600 women are diagnosed with breast cancer in Austria, and around 1,600 succumb to the disease each year, despite advancements in treatment.

Historically, mammography-based screening programs have been deemed vital for reducing breast cancer mortality. The earlier a cancer is detected, the more effective and less invasive the treatment can be, leading to higher survival rates. However, the Salzburg study sought to determine whether the breast cancer screening program had any impact on the incidence of advanced cancer stages.

Commencing in January 2014, Austria implemented a nationwide breast cancer screening program. The study analyzed data from the Salzburg tumor registry, which compiles all cancer cases diagnosed within the region. It included women residing in Salzburg who received an initial breast cancer diagnosis between 2010 and 2022, focusing on patients aged 45 to 69 with known tumor stages.

The researchers compared the frequency of mammary carcinomas detected during mammography screenings before and after the program's establishment. They examined data from 2010 to 2013 (prior to the program) and from 2016 to 2019 (post-implementation). Unfortunately, the analysis revealed little positive change. The distribution of cancer stages from 0 (pre-cancerous) to IV (metastatic disease) showed no statistically significant differences between the two periods.

While there was a slight decrease in the percentage of stage IV breast cancers diagnosed--from 9.4% to 4.5%--this change was not statistically significant. No meaningful distinctions were found between early stages (0 to I) and advanced stages (II to IV), nor between cases with or without lymph node involvement.

Prior to the screening program, 12.2% of breast carcinomas were diagnosed as pre-cancerous lesions; this figure only marginally increased to 13.4% afterward. Diagnoses for stage I cancers were 44.1% before the program and 46.2% afterward, while stage II figures showed a similar pattern, with 28.2% before and 29% after, and stage III from 6.1% to 6.9%. The relatively minor changes indicate that the screening initiative has not achieved its intended goals.

Moreover, the program aimed to enhance participation rates across various demographics, yet the study found no significant impact from factors such as age or urban versus rural residence on tumor stage at diagnosis. Interestingly, there was a slight, statistically insignificant decrease in overall breast cancer incidence in Salzburg, from 245.7 to 229.8 cases per 100,000 residents per year across the analyzed periods.

The study also highlighted that participation rates in the screening program remained stagnant, with only 45% of invited women in Salzburg attending between 2014 and 2021. When factoring in diagnostic mammograms, the breast cancer screening coverage for women aged 45 to 69 was 51%, a figure that closely mirrors the estimated 55% rate during the previously unorganized opportunistic screening efforts prior to the national program.

Crucially, the study does not offer evidence that the establishment of the screening program in Salzburg has led to a decrease in breast cancer mortality. The researchers focused on disease stage at diagnosis, as this parameter is less influenced by treatment and provides clearer insights into screening effectiveness.

It is essential to understand that advancements in breast cancer treatment over recent years have significantly influenced disease incidence and mortality rates. A recent simulation study from the U.S. indicated that the reduction in breast cancer mortality by 58% from 1975 to 2019 can largely be attributed to improved treatments for breast cancer stages I to III, while screening contributed only modestly to this decline.

As of the end of 2022, the Austrian screening program targeted women aged 45 to 69, with the age range expanded to 45 to 74 as of January 2023. Although this demographic represents the highest risk for breast cancer, only about 41% actively participate in mammography screenings. All women in this age group are automatically eligible for preventive mammography via their health insurance and receive invitations biennially to undergo screenings. Increased participation rates are likely to yield positive outcomes under the existing program framework.