Objective:The indication of adjuvant chemotherapy recommendation (ACR) in breast cancer patients with intermediate recurrence score (RS) is controversial.This study investigated the relationship between routine clinicopathological indicators and ACR,and established a nomogram for predicting the probability of ACR in this subset of patents.Methods:Data for a total of 504 consecutive patients with intermediate RS from January 2014 to December 2016 were retrospectively reviewed.A nomogram was constructed using a multivariate logistic regression model based on data from a training set (378 cases) and validated in an independent validation set (126 cases).A Youden-derived cut-off value was assigned to the nomogram for accuracy evaluation.Results:The multivariate logistic regression analysis identified that age,histological grade,tumor size,lymph node (LN) status,molecular subtype,and RS were independent predictors of ACR.A nomogram based on these predictors performed well.The P value of the Hosmer-Lemeshow test for the prediction model was 0.286.The area under the curve (AUC) values were 0.905 [95％ confidence interval (95％ CI):0.876-0.934] and 0.883 (95％ CI:0.824-0.942) in the training and validation sets,respectively.The accuracies of the nomogram for ACR were 84.4％ in the training set and 82.1％ in the validation set.Conclusions:We developed a nomogram to predict the probability of ACR in breast cancer patents with intermediate RS.This model may aid the individual risk assessment and guide treatment decisions in clinical practice.