Performances Of BI-RADS In The Malignant Risk Assessment Of Breast Mass And Non-mass Lesions

Objectives: The objectives of this study were to investigate the incidence of breast non-mass cancer,summarize the ultrasonographic features of breast mass lesions,with focus on non-mass lesions,compare the performance of breast imaging report and data system(BI-RADS)for the malignant risk evaluation of breast mass lesions with that for breast non-mass lesions,increase understanding of breast non-mass lesions,in order to improve the performance of ultrasound in the breast screening and evaluation of breast mass and non-mass lesions.Methods: In this retrospective study,some data of patients in the first affiliated Hospital of Hainan Medical University were reviewed,including:(1)The patients who had undergone ultrasound examination for breast lesions and had definite histopathological results of the breast mass lesions and non-mass lesions from January 2017 to December 2021;(2)The patients who had undergone ultrasound examination for breast lesions,without histopathological results,but follow-up for breast non-mass lesions for at least 24 months up to more than 4 times from January 2016 to December 2021.The gold standards for reference were that the histopathological results of the breast lesions,and the results of at least 24 months follow-up for the breast non-mass lesions.to calculate the incidence of breast non-mass cancer.Chi-square test and Fisher’s exact test were used to analyze the malignant risk factors of breast mass and non-mass lesions,the malignant rate of breast mass and non-mass lesions based on BI-RADS category was calculated,with reference to the gold standard.The receiver operating characteristic(ROC)curve was drawn,the area under the ROC curve(AUC)was calculated,and Youden index was determined and taken as the cut-off value for the determination of malignancy risk of the sensitivity and specificity.The positive predictive value(PPV)and negative predictive value(NPV)were calculated and compared.Results: The incidence of breast malignant lesion was 4.59%(47/1024)of all pathologically confirmed breast malignant lesions.There were 89 breast non-mass lesions and 182 breast mass lesions in the final analyses,who were all females.Of the breast non-mass lesions,there were 42 benign lesions and 47 malignant lesions,and the proportions were 47.19% and52.81%,respectively.Of the breast mass lesions,the proportions of benign and malignant lesions were 47.52% and 52.75%,respectively.There was no significant difference of proportions of the benign and malignant lesions between breast mass and non-mass lesions(P =1.000).Variables of age,body mass index,microcalcification and posterior echoic attenuation were significantly associated with the malignancy of breast non-mass lesions(all P <0.05).There were significant differences between the breast benign and malignant mass lesions in the distribution of patients’ age,menopausal history,history of breast diseases,shape of lesion,orientation of mass,margin of mass,calcification of lesion,posterior features of lesion,vasculature,and abnormal lymph nodes in the axilla(all P <0.05).With BI-RADS4 B as the optimal cut-off,the sensitivity,specificity,PPV,NPV and AUC of breast non-mass lesions and mass lesions were 82.98%,83.33%,84.78%,81.40%,0.83;81.25%,94.19%,93.98%,81.82%,0.88,respectively.There were significant differences of specificity and PPV between breast non-mass lesions and mass lesions(all P < 0.05),and there were no significant differences of sensitivity,NPV and AUC between breast non-mass lesions and mass lesions(all P >0.05).Conclusions:(1)Breast malignant lesion presents dominantly as breast mass lesion,and rare in breast non-mass lesion.(2)The BI-RADS classification has advantages in the evaluation of breast mass lesions,which can reduce and spare unnecessary biopsy,but it has lower specificity and PPV in the evaluation of breast non-mass lesions.(3)The outcomes of BI-RADS category for breast mass and non-mass lesions in this study were not consistent with the likelihood that BI-RADS recommendation,which suggest that the associated physicians-in-ultrasound need to enforce theoretical study,exercise analytical ability and further improve assessment of breast lesions.