Analysis Of Risk Factors For Sentinel Lymph Node Metastasis In Breast Cancer And The Significance Of Ultrasound For Evaluating Sentinel Lymph Node

Objective:To analyze the clinical-pathologic factors in patients with breast cancer, and to investigate the risk factors of sentinel lymph node and non-sentinel lymph node metastases, and follow-up was conducted. To evaluate the relating factors and predictive effect of ultrasound(US) in preoperatively identifying sentinel lymph node.Methods:The records of 1262 patients with breast cancer,(the total number is 1274 including 12 patients underwent bilateral sentinel lymph node biopsy,) on whom underwent sentinel lymph node biopsy(SLNB) in The fourth hospital of Hebei Medical University between January 2010 and June 2015 were retrospectively evaluated, and follow-up was conducted. We analyzed the correlative clinical-pathologic variables of patients with SLN metastases, and the prognostic factors related to non-sentinel lymph node(NSLN) metastases. At the same time, we evaluated the effect of ultrasound(US) and its relating factors in preoperatively identifying sentinel lymph node in breast cancer patients. Chi-square test and Logistic multivariate regression analysis were carried out in this study. A probability level of <0.05 was considered statistically significant.Results:There were 1262 patients(4 male patients included) underwent SLNB, while the total number is 1274 with another 12 patients underwent bilateral SLNB included. There were 4697 SLNs in all. The mean number of SLNs was 3.69. The median number was 3. 315 of 4697 SLNs were positive. There were 223 patients(17.5%) with positive SLNs, 1051 patients(82.5%) with negative SLNs. 766 patients underwent SLNB and axillary lymph node dissection(ALND), low level axillary lymph nodes dissection or axillary lymph nodes excision followed. All the nodes of dissection or excision were called NSLN. There were 195 patients with positive SLNs received axillary surgery, 65 of them had NSLN metastases, accounting for 29.15% of patients with positive SLNs(65/223). There were 574 patients with negative SLNs received axillary surgery among which 19 patients had positive NSLN, accounting for 1.81% of patients with negative SLNs(19/1051). Univariate analysis showed the menopausal status, ER status, PR status, pathologic type, vascular invasion were associated with SLN metastases in the two groups of patients. The difference was statistically significant(P<0.05). Multivariate analysis indicated PR(+) was an independent risk factor for SLN metastases( OR=1.949,95%CI=1.004-3.784), vascular invasion was an independent risk factor for SLN metastases(OR=2.686, 95%CI=1.816-3.972). Menopause was the protective factor for SLN metastases(OR=0.697, 95%CI=0.505-0.962). Multivariate analysis in pathologic type showed that compared to ductal carcinoma and ductal carcinoma in situ with microinvasion, invasive ductal carcinoma、invasive lobular carcinoma、invasive ductal-lobular carcinoma,Ductal carcinoma in situ with invasion and other pathologic types increased the risk of SLN metastasis by 24,28,57,7 and 13 times respectively. Age, body mass index(BMI), tumor location, the number of tumor, histological grading, histological type, HER-2 status, Ki-67, the number of SLN, surgical approach and other variable factors had nothing to do with SLN metastases, without statistically significant difference(P>0.05). Univariate analysis revealed that the number of positive SLNs was related to the NSLN metastases in patients with positive SLNs, the difference was statistically significant(P<0.05=. Multivariate analysis indicated the number of positive SLNs was an independent risk factor for the NSLN metastases(OR=2.766,95%CI=1.741-4.359). The number of tumor, tumor size(pathology), number of negative SLNs and vascular invasion were not statistically associated with NSLN metastases(P>0.05). In ultrasonic test, univariate analysis showed the aspect ratio of lymph nodes were related to the NSLN metastases, the difference was statistically significant(P < 0.05 =. Multivariate analysis indicated the aspect ratio of lymph nodes was an independent risk factor for the SLN metastases(OR=0.317,95%CI=0.196-0.513). A total of 1262 patients were followed up and 179 patients of which were missed, the rate of follow up was 85.82%.The median follow-up time was 18 months, during which time 1 patient died of liver metastasis, 2 patients died of non-cancer, 16 patients suffered recurrence and metastasis, 4 of them were patients with positive SLN undergoing ALND. Another one was patient with positive SLN without undergoing ALND. Among 16 patients there were 1 lung metastasis, 4 liver metastasis, 6 bone metastasis, 6 lymph node metastasis, accounting for 6.25%, 25%, 37.5%, 37.5% respectively of recurrent cases. And one of the patients presented local recurrence, 2 patients had multiple organ metastasis.Conclusions:PR status, vascular invasion are independent risk factors for SLN metastases, Patients with PR(+)have a higher risk of SLN metastases. Menopause is the protective factor for SLN metastases, menopause women have a lower risk of SLN metastases. Multivariate analysis in pathologic type shows that compares to ductal carcinoma and ductal carcinoma in situ with microinvasion, invasive ductal carcinoma 、 invasive lobular carcinoma 、invasive ductal-lobular carcinoma,Ductal carcinoma in situ with invasion and other pathologic types increase the risk of SLN metastasis by 24,28,57,7 and 13 times respectively. The number of positive SLNs is an independent risk factor for NSLN metastases, the more number of SLN(+),the higher risk of NSLN metastases. Ultrasound report indicates the lymph node aspect ratios as an independent protective factor of SLN,while the lymph node aspect ratios ≤2,the risk of SLN metastases become higher.