Association of tumour stiffness on sonoelastography with axillary nodal status in T1 breast carcinoma patients.

OBJECTIVES: To evaluate whether tumour stiffness on sonoelastography is associated with axillary nodal metastasis in T1 breast carcinoma patients.
METHODS: Between May 2006 and December 2010, 200 consecutive women (mean age, 51.6; range, 27 - 81 years) who underwent B-mode ultrasound (US), sonoelastography, and curative surgery with axillary nodal evaluation for clinically node negative T1 breast carcinomas (mean invasive tumour size, 12.4; range, 3 - 20 mm at pathology) were identified. The association between the elasticity score of the tumour and histopathological axillary nodal status was evaluated using a logistic regression model after controlling for imaging and clinicopathological variables of the tumour.
RESULTS: The overall incidence of axillary nodal metastasis was 15.5 % (31 of 200). Axillary nodal metastasis was significantly more frequent in tumours with elasticity scores ≥4 than in tumours with elasticity scores <4 (21.7 % vs. 4.2 %; P < 0.001). At multivariate analysis, an elasticity score ≥4 [odds ratio (OR), 6.95; P = 0.004], US size >10 mm (OR, 5.98; P = 0.022), and lymphovascular invasion (OR, 10.68; P < 0.001) of tumours were independently associated with axillary nodal metastasis.
CONCLUSIONS: Tumour stiffness on sonoelastography is independently associated with axillary nodal metastasis in T1 breast carcinoma patients. KEY POINTS: • Prediction of axillary nodal status using imaging techniques is valuable. • High ultrasound elasticity scores of T1 tumours were associated with axillary metastasis • Node-positive T1 tumours frequently had elasticity scores 4 or 5. • Sonoelastography might render axillary surgery unnecessary in T1 breast carcinoma patients.