BACKGROUND: The effectiveness of the Dutch breast cancer screening programme depends on the quality of the full trajectory, from the first screening to the final treatment of a screen-detected breast cancer. Interhospital variation in breast cancer treatment has been explored by several studies, however, not specifically in a screen-detected breast cancer population. The current study compares the treatment strategies of women with screen-detected breast cancer between hospitals in the South of the Netherlands. METHODS: A total of 1450 women with screen-detected breast cancer, who participated in the Dutch screening programme between January 2009 and July 2019, were included in this retrospective analysis of a prospectively obtained database. Breast cancer treatment (i.e. preoperative MRI, neoadjuvant systemic therapy and type and outcomes of surgery) was compared between hospitals using multivariate analysis. RESULTS: Statistically significant interhospital variation was observed in the use of preoperative MRI (range 20.8-35.8 %, p <
0.001), neoadjuvant systemic therapy (range 4.0-13.3 %, p <
0.001) and breast conserving surgery (range 70.0-87.1 %, p <
0.001). These differences persisted after adjustment for case-mix. In patients with invasive breast cancer treated by breast conserving surgery, the mean volume of the resection specimen ranged from 381 to 541 ml between hospitals (p <
0.001). However, this was not accompanied by significant differences in the percentage of patients with positive resection margins (range 2.9-5.7 %, p = 0.34). CONCLUSIONS: We observed significant interhospital variation in the management of women with screen-detected breast cancer. Quality assurance in screen-detected breast cancer may reduce these differences, but evolving breast cancer care and more personalised approaches should be accounted for.