超声判断乳腺癌患者腋淋巴结转移的多因素分析

目的 观察乳腺癌患者原发灶及腋下淋巴结（LN）的超声诊断图像和彩色Doppler特点,分析淋巴结转移（LNM）的相关因素,以获得超声诊断乳腺癌患者腋下LNM的较佳组合指标。方法 超声观察113例乳腺癌患者的原发灶和腋LN。观察原发灶的位置、最大径、数量、内部钙化灶边带回声、边界、肿瘤内部的血流丰富程度分级（0-Ⅲ级）、最高流速和阻力指数;观察患侧腋LN目最大径、纵横比、纵切面皮质厚度与淋巴门厚度比值（皮／门比）、皮质局部最大厚径、淋巴结的血流分布类型、最高流速和阻力指数。全部患者均进行乳房改良根治术,以腋LN清扫的病理结果作为金标准,对与LNM相关的影像及临床因素进行单因素及多因素分析（Logistic回归）,并利用受试者工作率性（ROC）曲线评价诊断指标。结果 113例乳腺癌患者的超声观察指标单因素分析结果显示,原发灶的最大径、多发或弥漫、血流丰富度,对腋LNM有影响,差异有统计学意义（P=0．029-0．005）腋LN的纵横比、皮／门比、皮质局部最大厚径、血流分布类型与腋LNM有关,差异有统计学意义（P=0．000）。将单因素分析有意义的指标进行多因素分析,与腋LNM有关的影响因素为：LN的皮／门比LN的纵横比以及原发灶的最大径,利用ROC曲线评价各单项指标及其不同组合指标的诊断价值结果显示,LN皮／门比＋LN纵横比＋原发灶最大径这一组合指标最优,其ROC曲线的线下面积最大,即灵敏度和特异度之和最大。结论 对乳腺癌患者进行腋LN超声扫查,综合考虑原发灶大小LN的纵横比、皮质厚度及其与淋巴门厚度的比例关系,将有助于提高超声诊断腋LNM的正确率,较为准确地判断腋LN的状态。

Evaluation of the ultrasonographic features of axillary lymph node metastasis in breast cancer

Objective To analyze the ultrasonographic features of axillary lymph node metastasis in breast cancer patients, and to evaluate the accuracy of these features by Receiver Operating Characteristic (ROC)curve. Methods Ultrasonography was carried out in 113 patients (mean age 56.5 yr, range 29-77 yr). The ultrasonogrphic features of the primary tumor and the axillary lymph node were observed. Univariate analysis was performed by Chi-squared test and Fisher exact test, and multivariate analysis to determine independent significant individual variables by multiple logistic regression analysis. ROC curve analysis was done to determine the sensitivity and specificity of individual and combined ultrasonographic features in distinguishing metastatic lymph node from the normal one. Results The primary tumor size, abundance of blood supply in the primary tumor, longitudinal-transverse diameter ratio, cortex-hilum thickness ratio (on the longitudinal section), abnormal cortex thickness, distribution of intra-nodal vascularity of axillary lymph nodes were found to be statistically significant factors by univariate analysis. The primary tumor size, longitudinal-transverse ratio and cortex -hilum thickness ratio of lymph node were proved to be significant independent predictors of axillary lymph node metastasis by logistic regression analysis. Through ROC analysis, the combination of these independent ultrosonographic feature predictors was found to contribute significantly in differentiating metastatic lymph node from the normal with a sensitivity of 88.6% and specificity of 84.5%. Conclusion Axillary ultrasonography is helpful in staging the axillary lymph node in breast cancer patient. The primary tumor size, longitudinal-transverse diameter ratio and cortex-hilum thickness ratio of lymph node are the main features to determine whether metastatic involvement is present or not.