Validation Of MSKCC Nomogram In Predicting Non-SLN Metastasis Of Breast Cancer And Retrospective Study Of The Applicative Indicatio Of ACOSOG Z0011 Trial Towards Chinese Patients

Background and Purpose:This study retrospectively analyzed the clinicopathological characteristics of patients with positive sentinel lymph node(SLN), and explored the risk factors for non-sentinel lymph node(NSLN) metastasis, then we validated the value of the Memorial Sloan Kettering Cancer Center(MSKCC) nomogram for the prediction of NSLN metastasis in Chinese patients with breast cancer; Additionally, we analyzed the relativity between tumor burden and non-SLN metastasis in a Chinese patient population, then assess Z0011 trial result application to Chinese women patients.Methods:Data on 2431 patients who received sentinel lymph node biopsy(SLNB) at the Shandong Cancer Hospital from December 2001 to January 2015 were collected in this study, and data on 766 patients with positive SLN were analyzed to evaluate the risk factors for non-SLN metastasis. The MSKCC nomogram was used to calculate the probability of non-SLN metasta?sis and was compared with actual probability after grouping into deciles. A receiver-operating characteristic(ROC) curve was drawn and predictive accuracy was assessed by calculating the area under the ROC curve. Furthermore, we screened the patients met the criterion of Z0011 in addition to the operational manner to analyze the effect of tumor burden to the NSLN positive rate, and compared the non-SLN positive rate of different tumor size subgroup with its of Z0011 ALND group in order to get the Indicatio of ACOSOG Z0011 Trial towards Chinese Women Patients.Results:Tumor size, histological grade, lymphovascular invasion, multifocality, number of positive SLNs, and number of negative SLNs were correlated with non-SLN metastasis(P<0.05) by univariate analysis. And multivariate analysis showed that tumor size, histological grade,lymphovascular invasion, number of posi?tive SLNs, and number of negative SLNs were identified as independent predictors for non-SLN metastasis. The trend of actual probability in various decile groups was comparable to the predicted probability. The area under the ROC curve was 0.752. The tumor burden of ALND group in Z0011 trial was obviously lower than this study. The tumor burden( tumor size and positive-SLNs number)had significant differences between Non-SLN(+) group and Non-SLN(-) group, and the positive rate of Non-SLN and ≥3 Non-SLNs(+) rate can increase along with the tumor size. The NSLN positive rate of patients whose tumor size was 0-2cm was the most similar with ALND group in Z0011 trial(26.94% vs 27.3%).Conclusion:The MSKCC nomogram can provide an accurate prediction of the probability of non-SLN metastasis, and offers a reference basis about axillary lymph node dissection. Tumor size or SLNs status did affect the rate of Non-SLN(+), and the Non-SLN(+) burden would rise significantly with the increase of tumor size. Moreover, Z0011 trial had lower tumor burden than our data. According to the statistical results of our study, the applicative indications of Z0011 trial in Chinese women patients should be limited to T1 tumor by comparing the Non-SLN(+) rates of our study with the ACOSOG Z0011 trial.