Objective To study the factors influencing the non-sentinel lymph node(NSLN) status and to assess Memorial Sloan-Kettering Cancer Center (MSKCC) nomogram performance in predicting SLN metastases in a sentinel lymph node(SLN) positive Chinese breast cancer population. Methods Data were collected from breast cancer patients who were diagnosed with pathological positive sentinel lymph node and received further axillary lymph node dissection(ALND) in Shanghai Ruijin Hospital from January 2011 to August 2014. Use MSKCC nomogram to calculate each patient's NSLN metastasis risk score. The receiver operator characteristic curve(ROC curve)and the area under the ROC curve(AUC)was used to assess the predictive accuracy of the model. Results Among the 1147 patients who received sentinel biopsy in our center, 150 SLN positive patients who received ALND were enrolled in this study. By univariate analysis, multifocal breast cancer (P = 0.017), SLN+/SLN ratio (P = 0.010) and axillary lymphadenopathy displayed by ultrasound(P = 0.005) are the influencing factors of NSLN metastases. By multivariate analysis, multifocal breast cancer (OR 7.25, 95% CI 1.73∼30.43, P = 0.007), SLN+/SLN ratio≥0.5 (OR 2.564, 95% CI 1.22∼5.39, P = 0.013) and axillary lymphadenopathy displayed by ultrasound (OR 2.471, 95% CI 1.18∼5.19, P = 0.017) are the independent influencing factors of NSLN metastases. The AUC of MSKCC nomogram in this population is 0.677. Conclusion For breast cancer patients with positive sentinel lymph node, multifocality, SLN+/SLN ratio and axillary lymphadenopathy displayed by ultrasound is related to NSLN metastasis. MSKCC has low accuracy in predicting NSLN status of this population.

Citation Format: Huang J, Chen X, Shen K, Li Y, Chen W, He J, Zhu L, Huang O, Zong Y, Fei X, Jin X. Risk factors of non-sentinel lymph node metastasis in breast cancer patients with metastatic sentinel lymph node. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P3-01-13.