The Ultrasound Diagnostic Value Of Axillary Lymph Node Metastasis In Primary Breast Cancer Patients

Objective: Axillary lymph node status is one of the most important prognostic factors of breast cancer.Pre-operative ultrasound diagnosis of axillary lymph node status is the key to developing comprehensive treatment,staging and prognosis of breast cancer.However,there are few false negative data on ultrasound diagnosis of axillary lymph node metastasis in Chinese women.Therefore,in this study we aimed to investigate the value of ultrasonography in the diagnosis of axillary lymph node metastasis of primary breast cancer,and analyzed whether there was population with higher risk of false negative axillary lymph node metastasis caused by ultrasonography,and its correlation with prognosis.Methods: This study retrospectively analyzed 3,361 patients with primary breast cancer diagnosed in the Breast Center of the Fourth Hospital of Hebei Medical University from January 2010 to December 2012 and all patients underwent routine preoperative ultrasonography and intraoperative axillary lymph node dissection(ALND).According to the screening criteria of this study,2,357 patients were enrolled finally.Among them,1,732 patients with negative axillary lymph nodes were preoperatively diagnosed by ultrasound and 625 patients with positive axillary lymph nodes.False negative axillary lymph nodes were defined as those with no metastasis of axillary lymph nodes by ultrasound but confirmed by pathology after operation.True negative was defined as the axillary lymph node metastasis which was not confirmed by pre-operative ultrasound and post-operative pathology.From the date of follow-up to July 2016,all clinical data collected was established into a database and factors that may affect axillary lymph node metastasis or prognosis in breast cancer patients were selected and quantified.The data was entered into SPSS 24.0 for statistical analysis,and P < 0.05 was set as statistically significant.Chi-square test and binary logistic regression analysis were used to compare the clinicopathological features(age,size of primary lesion,ER expression,etc.)between groups.The survival of patients was analyzed by Kaplan-Meier method,and the survival rate was compared by Log-rank test.Results:1.The sensitivity,specificity and accuracy of axillary ultrasound in this cohort were 66.24%,76.62% and 73.87%.2.By comparison of clinicopathological features of patients with primary breast cancer between ultrasound diagnosis of axillary lymph node false-negative and ultrasound true-negative,we found significant different(P<0.05)in age(P=0.002),the size of the primary tumor(P = 0.008),estrogen receptor expression(P=0.005),progesterone receptor expression(P=0.007),nuclear proliferating antigen Ki-67 expression(P=0.030),vascular tumor thrombus(P<0.001),and histological grade(P<0.001).Patients with younger age(26.4% vs 20.2%),larger tumor size(27.5% vs 21.9%),ER positive(25.2% vs 18.8%),high PR expression(25.7% vs 20.1%),high Ki-67 expression(24.5% vs 18.7%),and visible vascular tumor thrombus(43.3% vs 19.6%)and higher histological grade(35.2% vs 22.9%)had a higher proportion in the ultrasound false-negative group.3.Prognostic analysis of false-negative and true-negative ultrasonographic diagnosis of axillary lymph node metastasis: When no lymph node metastasis was found by pre-operative ultrasound,there was no statistical difference in the prognosis of patients between axillary lymph node metastasis less than or equal to 3 and no axillary lymph node metastasis by post-operative pathology,among those with age(>50 years old),primary tumor size(<2 cm),Ki-67<20% and histological grade 1 or 2(overall survival,P=0.074;disease-free survival,P=0.074).In addition,only one patient(1.8%)had lymph node metastasis > 3 in this group.Conclusion:1.Preoperative ultrasound diagnosis of axillary lymph node status in primary breast cancer is a feasible method.2.Preoperative ultrasound diagnosis of axillary lymph node metastasis has a higher false-negative when the patient is younger,primary lesion is larger,ER-positive,high PR expression,high Ki-67 expression,and visible vascular tumor thrombus and histological grade is higher.3.When no axillary lymph node metastasis was found by pre-operative ultrasound,it is no statistical difference of prognosis in patients who have a advanced age,small tumor size,low expression of Ki-67 and low histological grade between those axillary lymph node metastasis less than or equal to 3 and without axillary lymph node metastasis by post-operative pathology.Therefore,patients who meet the above criteria might avoid the surgery of axillary lymph node when the pre-operative ultrasound diagnosis of axillary lymph node metastasis is negative.