Background and AimTest‐sets are standardized assessments used to evaluate reader performance in breast screening. Understanding how test‐set results affect real‐world performance can help refine their use as a quality improvement tool. The aim of this study is to explore if mammographic test‐set results could identify breast‐screening readers who improved their cancer detection in association with test‐set training.MethodsTest‐set results of 41 participants were linked to their annual cancer detection rate change in two periods oriented around their first test‐set participation year. Correlation tests and a multiple linear regression model investigated the relationship between each metric in the test‐set results and the change in detection rates. Additionally, participants were divided based on their improvement status between the two periods, and Mann–Whitney U test was used to determine if the subgroups differed in their test‐set metrics.ResultsTest‐set records indicated multiple significant correlations with the change in breast cancer detection rate: a moderate positive correlation with sensitivity (0.688, p < 0.001), a moderate negative correlation with specificity (−0.528, p < 0.001), and a low to moderate positive correlation with lesion sensitivity (0.469, p = 0.002), and the number of years screen‐reading mammograms (0.365, p = 0.02). In addition, the overall regression was statistically significant (F (2,38) = 18.456 p < 0.001), with an R² of 0.493 (adjusted R² = 0.466) based on sensitivity (F = 27.132, p < 0.001) and specificity (F = 9.78, p = 0.003). Subgrouping the cohort based on the change in cancer detection indicated that the improved group is significantly higher in sensitivity (p < 0.001) and lesion sensitivity (p = 0.02) but lower in specificity (p = 0.003).ConclusionSensitivity and specificity are the strongest test‐set performance measures to predict the change in breast cancer detection in real‐world breast screening settings following test‐set participation.