BackgroundThe main purpose of the study reported here was to validate the clinical value of the Memorial Sloan Kettering Cancer Center (MSKCC) nomogram that predicts non-sentinel lymph node (SLN) metastasis in SLN-positive patients with breast cancer.MethodsData on 1,576 patients who received sentinel lymph node biopsy (SLNB) at the Shandong Cancer Hospital from December 2001 to March 2014 were collected in this study, and data on 509 patients with positive SLN were analyzed to evaluate the risk factors for non-SLN metastasis. The MSKCC nomogram was used to estimate the probability of non-SLN metastasis 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.ResultsTumor 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. However, multivariate analysis showed that tumor size (P=0.039), histological grade (P=0.043), lymphovascular invasion (P=0.001), number of positive SLNs (P=0.001), and number of negative SLNs (P=0.000) 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 0.722. Patients with predictive values lower than 10% (97/492, 19.7%) had a frequency of non-SLN metastasis of 17.5% (17/97).ConclusionThe MSKCC nomogram can provide an accurate prediction of the probability of non-SLN metastasis, and offers a reference basis about axillary lymph node dissection. Axillary lymph node dissection could be avoided in patients with predictive values lower than 10%.

99 Background: Even though the 2009 AJCC incorporated the internal mammary sentinel lymph node biopsy (IM-SLNB) concept, there has been limited change in surgeons practice patterns due to the low visualization rate of the internal mammary sentinel lymph nodes (IM-SLNs) with the conventional injection technique (average 13%, 0~37%). In this prospective study, different radiotracer injection techniques were evaluated to achieve a relative high visualization and detection rate of IM-SLNs (NCT01642511). Methods: The 190 patients enrolled in this study were divided into three groups according to the study period and radiotracer (99mTc-labeled sulfur colloid) injection technique. Group A: conventional technique (radiotracer injection only into the tumor quadrant) for the initial 58 cases; Group B: two-quadrant injection at the 6 and 12 o’clock positions, 2.0~3.0 cm from nipple in the latter 132 cases. Group B was then separated into two groups according to the radiotracer injection volume: Group B1, low volume (<0.5ml/point, n=41); Group B2, high volume (≥0.5ml/point, n=91). Radiotracer was injected into the parenchyma under the ultrasonographic guidance for all patients. IM-SLNB was performed for patients with IM-SLNs visualized on preoperative lymphoscintigraphy and/or detected by intraoperative gamma probe. Results: Group B was associated with a significantly higher IM-SLNs visualization rate (76.5%, 101/132) compared to Group A (15.5%, 9/58, P=0.000), and Group B2 with the highest visualization rate (86.8% vs. 53.7% Group B1, P=0.000). All techniques had the same visualization rate of the axillary SLNs (P=0.915). The visualization rate of IM-SLNs was related to the patient’s age (P=0.037) and injection volume (P=0.000). The successful rate of IM-SLNB was 92.3%, and arrived 100% after 20 cases learning curve. The postoperative IM-SLNB complications were 0. Conclusions: Modified technique of radiotracer injection (Qiu's injection technique: two-quadrant, high volume and ultrasonographic guidance) significantly improved the visualization rate of IM-SLNs, provided an effective technique to evaluate the status of internal mammary, and would promote research on the IM-SLNB.