To investigate ultrasound signs and clinicopathological characteristics of triple negative breast cancer (TNBC) and its risk factors of axillary lymph node metastasis.

The clinical data of 105 female patients diagnosed with TNBC and admitted to Changzhou Second People's Hospital from March 2016 to May 2020 were retrospectively analyzed.All cases were single-sided breast cancer with only one lump and underwent routine ultrasound examination before operation. According to pathological results,the patients were divided into anaxillary lymph node metastasis (LNM) group and a non-lymph node metastasis(NLNM) group.Ultrasound signs (such as tumor diameter, aspect ratio, shape, margin, echo, internal blood flow, and calcification) and clinicopathological characteristics (such as age, menopausal status, body mass index [BMI],histological grade and pathological type) of the two groups were compared to identify the factors that affect axillarylymph node metastasis in TNBC patients.

A total of 105 female TNBC patients were enrolled, including 38 cases in the LNM group and 67 cases in the NLNM group, aged 25 to 88 (52±12) years.There were no significant differences in ultrasound signs of the two groups,including tumor diameter, form, aspect ratio, margin, echo, blood flow, and calcification (P＞0.05 for all). The histological grade and BMI were statistically different between the two groups (P＜0.05 for both). The proportion of patients with high histological grade (grades Ⅱ-Ⅲ and Ⅲ) and a BMI＜25 kg/m² in the LNM group were significantly higher than those in the NLNM group (χ²=4.056, 5.244, P＜0.05 for both). Binary logistic regression analysis showed that BMI＜25 kg/m² was a risk factor affecting axillary lymph node metastasis of TNBC patients (OR=0.360, P=0.024). There was no statistical difference between the two groups in age, menopausal status, or pathological type (P＞0.05 for all).

There is no predictive value of TNBC ultrasound signs in axillary lymph node metastasis. BMI＜25 kg/m² are helpful for judging axillary lymph node metastasis in TNBC patients.