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.