Objective To analyze the clinical value of sound touch elastography (STE) and sound touch quantify (STQ) combined with carbohydrate antigen 153 (CA153) in the early identification of breast tumors of breast imaging reporting and data system (BI-RADS) categories 3 to 5. Methods The clinical data of 116 patients with breast tumors of BI-RADS categories 3 to 5 from January 2019 to December 2021 in the hospital were retrospectively analyzed. According to the results of surgical (or biopsy) pathological examinations

the patients were divided into malignant group (malignant tumors) and benign group (benign tumors). STE and STQ were used to measure the elasticity moduli of all patients before surgery

and serum CA153 was detected. The success rates of STE and STQ measurements and the consistency between different operators [inter-group correlation coefficient (ICC)] were compared. After excluding the cases with failed STE or STQ measurement

the elasticity moduli of STE measurement and STQ measurement and serum CA153 level were compared between the two groups. Receiver operating characteristic (ROC) curve was applied to evaluate the differential value of STE

STQ

serum CA153 and their combined detection on breast tumors of BI-RADS categories 3 to 5. Results The success rate of STE measurement was significantly higher than that of STQ (P<0.05)

and its measurement consistency ICC coefficient was also higher than that of STQ (0.932 vs 0.894). After excluding the 12 patients with failed STQ measurement

the remaining 104 patients included 39 cases in malignant group and 65 cases in benign group. The elasticity modulus of STE or STQ measurement and serum CA153 level in malignant group were significantly higher than those in benign group (P<0.05). ROC curve analysis showed that the elasticity moduli measured by STE and STQ and serum CA153 had high differential value on malignant tumors among breast tumors of BI-RADS categories 3 to 5 (P<0.05)

and the cut-off values were 4.28 m/s

4.78 m/s and 23.43 U/mL. The combined detection of elasticity modulus measured by STE or STQ and serum CA153 had higher differential value than single detection

and their AUCs were 0.946 and 0.932 respectively. Conclusion The combined detection of elasticity modulus measured by STE or STQ and serum CA153 has higher identification value on breast tumors of BI-RADS categories 3 to 5

and STE collects more data and is more stable than STQ.