T-stage and positive sentinel nodes ratio are the useful factors to predict non-sentinel node metastasis in breast cancer patients with macro-metastasis in the sentinel node

• The size of sentinel lymph node metastasis has been reported to be predictive factor of non-sentinel node metastasis.
• We analyzed the predictive factor of non-sentinel node metastasis with macrometastasis of sentinel node.
• Using T-stage and SN ratio we might find it possible to omit axillary dissection in cases with of sentinel node.

IntroductionCurrent guidelines recommend completion axillary lymph node dissection (cALND) in case of a sentinel lymph node (SN) metastasis larger than 2 mm (macrometastasis). However in many patients of those, the non-sentinel lymph nodes (NSN) contain no further metastasis, indicating that axillary lymph node dissection provides no benefit. To identify cases who could have undergone omission of the ALND with confidence, we have retrospectively evaluated the predictive factors of NSN metastasis with positive macrometastasis in the SN.MethodsThis study was based on a retrospective database of 420 patients who underwent sentinel lymph node biopsy (SNB) for breast cancer, of whom 61 patients had SN macrometastasis intra- and postoperatively. We examined predictive factors of NSN involvement in 51 cases of these 61 patients who underwent cALND. All clinical and histological variables were analyzed according to NSN status, by using Mann–Whitney U test, univariate and multivariate logistic regression model.ResultsT stage and the proportion of involved SNs among all identified SNs (SN ratio) were correlated with NSN metastasis. Univariate and multivariate analysis showed that T stage and SN ratio were the independent predictive factor of NSN metastasis. The area under ROC curve for SN ratio was 0.71. The best cut off value of SN ratio was 0.667. Negative predictive value to NSN metastasis in cases with both T2 and more than 0.667 of SN ratio was 85.7%.ConclusionIn patients with invasive breast cancer and macrometastasis of SN, T stage and SN ratio were useful for prediction of NSN metastasis.