Ultrasound Diagnosis of Sentinel Lymph Nodes in Breast Cancer Based on the P Value Method

It is essential to determine the location and evaluate the status of the sentinel lymph node (SLN) in breast cancer patients before surgery. However, the diagnostic performance of the conventional ultrasound (US) examination and lymphatic contrast-enhanced US (LCEUS) was not satisfied. This study aimed to explore the US diagnostic value of the relative p value method for SLN in breast cancer, to provide reference for precise clinical diagnosis.

A retrospective collection of 157 breast cancer patients who were admitted to the Affiliated Hospital of Nanjing University of Chinese Medicine from July 2018 to December 2022 was conducted. All patients underwent US and LCEUS examinations before surgery and confirmed by pathology. Because pathology was considered the gold standard, the diagnostic efficacies of US, LCEUS, US + LCEUS, the p value method and the p value method + LCEUS were analyzed.

Using pathology as the gold standard, there were 68 cases (43.31%) in the SLN metastasis-positive group including macro-metastasis and micro-metastasis, whereas the SLN metastasis-negative group included 89 cases (56.69%), including no metastasis and isolated tumor cell clusters. Among 157 SLNs of breast cancer patients, five methods (ie, US, LCEUS, US + LCEUS, p value and p value + LCEUS) in diagnosing SLNs achieved, respectively, an accuracy of 80.25%, 81.53%, 79.62%, 84.08% and 83.44%; sensitivity of 76.47%, 77.94%, 88.24%, 85.39% and 92.65%; specificity of 83.14%, 86.52%, 73.03%, 82.35% and 76.40%; positive predictive value (of 77.61%, 81.54%, 71.43%, 86.36% and 75.00%; and negative predictive value of 82.22%, 83.70%, 89.04%, 81.16% and 93.15%. Additionally, the sensitivity of the p value + LCEUS method showed statistically significant differences when compared with that of the US and the LCEUS method, respectively (p < 0.05). A statistically significant difference in negative predictive value was observed between the US and the p value + LCEUS method (p < 0.05). Receiver operating characteristic curves were plotted for the diagnostic sensitivity of five groups (i.e., US, LCEUS, US + LCEUS p value and p value + LCEUS) in diagnosing SLNs of the breast. The areas under the curve (AUC) were 0.798, 0.822, 0.806, 0.839 and 0.845, respectively. No statistically significant differences were found in the pairwise comparisons.

The method of predicting the metastasis status of SLN based on pre-operative LCEUS and the p value method can assist clinicians in assessing the risk of SLN metastasis before surgery. It is possible to decrease unnecessary SLN biopsies in low-risk patients and lower the incidence of complications.