The predict value of lymph node status pre-operation by ultrasound, mammography and MRI in early breast cancer.

BACKGROUND

Breast cancer is the most common cancer worldwide and ranks as the leading type among women in Taiwan. Traditionally, axillary lymph node dissection (ALND) has been the standard for early-stage breast cancer; however, for cases without lymph node involvement, particularly small tumors, this procedure may offer limited benefit and could lead to severe complications such as arm lymph-edema.

OBJECTIVE

This study aimed to assess the accuracy of ultrasound, mammography, and MRI in preoperative prediction of axillary lymph node status in early-stage breast cancer patients, with the goal of reducing unnecessary ALND.

METHODS

We prospectively analyzed data from primary breast cancer patients at a medical center in northern Taiwan, collected between 2023 and 2024. After excluding cases with incomplete pre-operative imaging or prior neo-adjuvant treatment, 247 patients remained and 51 patients had lymph node metastasis.

RESULTS

The combination of ultrasound and MRI yielded the highest diagnostic performance, with a sensitivity of 72.6 %, specificity of 85.2 %, and Youden's index of 0.43. In contrast, ultrasound alone showed 54.9 % sensitivity and 84.2 % specificity; mammography alone showed 29.4 % sensitivity and 96.4 % specificity; MRI alone showed 47.1 % sensitivity and 89.8 % specificity. A decision tree integrating imaging results with tumor histologic grade, size (≥2 cm), and HER-2 expression further improved prediction accuracy.

CONCLUSION

Combined ultrasound and MRI evaluation, when integrated with tumor grade, size, and HER-2 status, offers a reliable approach for preoperative prediction of lymph node metastasis. This method may reduce unnecessary axillary surgery and its associated complications.