Background: Population-based screening might be associated with a higher likelihood of a (ultra)low risk tumor assessed by the 70-gene signature (MammaPrint) (ultralow defined as indexscore >0.6, no distant metastasis observed at 5 years in the original 78 patients). The aim of this study is to determine the proportion of biologically (ultra)low risk tumors among the screen-detected tumors and to evaluate the impact of the analog versus digital screening technique. Methods: All Dutch breast cancer patients enrolled in the MINDACT trial (EORTC-10041), who were invited for the Dutch screening program (biennial, age 50-75), were included (n=1409). The proportions of 70-gene signature high, low and ultralow risk were calculated for patients with screen-detected (n=775), interval (n=390), and symptomatic, non-screening (n=244) carcinomas, taking into account analog vs. digital technology. Co-variants such as age, tumor size, grade, histological type, ER, HER2 and nodal status were included in the analyses. Results: Among the screen-detected tumors, 31.5% had a high risk, 31.2% a low risk and 37.3% an ultralow risk 70-gene signature result, compared to 47.4%, 28.5% and 24.1% among the interval carcinomas, respectively (p=0.001). Among the screen-detected carcinomas, 40.6% were detected using analog (n=315) and 59.4% using digital mammography (n=459). When using digital imaging a shift was seen among the screen-detected tumors in the proportions of high risk tumors from 27% to 35% and ultralow risk from 42% to 34%, low risk proportions remained the same (31%)(p=0.011). No such difference was seen for other tumor characteristics. Conclusions: Screen-detection was found to be associated with a higher likelihood of a biologically low risk tumor. The transition from analog to digital mammography resulted in a smaller proportion of ultralow risk and a larger proportion of high risk tumors among the screen-detected carcinomas.