New breast cancer screening programme in Switzerland may save lives

Breast cancer is the most frequently diagnosed cancer in women in Switzerland. Every year, 6,500 women are diagnosed with the disease, 550 of them in the cantons of St.Gallen and Graubünden.

In most cases, women over the age of 50 are affected. With the "donna" breast cancer early detection programme, cantons want to help ensure that breast cancer is detected earlier and can therefore be treated more effectively. Women aged between 50 and 69 are therefore invited by "donna" in writing every two years to undergo a voluntary X-ray examination of the breast, known as a mammogram.

As part of a research collaboration, the School of Medicine and the Cancer League of Eastern Switzerland have analysed data from the "donna" breast cancer screening programme from 2010 to 2019 in St.Gallen and Graubünden. A total of 2,900 cases of breast cancer were evaluated. The five-year survival rate for women who took part in the programme was over ten percentage points higher than for those who did not undergo screening.

One quality criterion of effective screening programmes is the minimisation of so-called interval cancers. These occur between two screening examinations. This means that if an initial examination is declared normal but breast cancer is diagnosed within 24 months of the screening, this is an interval carcinoma.

Women diagnosed with breast cancer who took part in the "donna" programme had a significantly better five-year survival rate (96.5 percent) than women outside the programme (86.1 percent). The significantly higher survival rates can be attributed in part to the fact that the breast cancer was detected at an earlier stage.

Only half as many breast cancer removals, so-called mastectomies, and significantly fewer chemotherapies had to be carried out in women who took part in the "donna" programme. Women within the "donna" programme who developed an interval carcinoma within two years of screening still had a significantly higher survival rate than women who did not take part in the screening.

Minimise risk factors and test AI software

"Early detection of cancer is not only beneficial for the individual woman, but also prevents the treatment of severe disease progression and thus also saves resources in our healthcare system," says Prof Dr Alexander Geissler, Professor of Management in Healthcare at the School of Medicine. The results mentioned are just the beginning, as the cooperation project is continuing. The research team at the School of Medicine will continue to work with experts from the "donna" programme and the cancer registry and, among other things, use artificial intelligence (AI) in breast cancer diagnostics. AI software is already being tested. In the event of positive study results, it will support radiologists within the "donna" programme in the evaluation of mammograms in future. Initial international publications indicate the potential of such software applications in terms of improved sensitivity and efficiency.