Intraoperative Molecular Analysis of Total Tumor Load in Sentinel Lymph Node: A Predictor of Axillary Status in Early Breast Cancer

Background: Axillary lymph node dissection (ALND) remains the standard of care in breast cancer patients with positive sentinel lymph node (SLN). However, approximately 40–60% of patients with positive SLNs have not developed to non-SLN metastasis and ALND seems to be an overtreatment. The purpose of this study was to analyze predictors and define a specific cut-off of total tumor load (TTL) of CK19 that can be used as a predictive factor of non-SLN metastasis in early breast cancer patients. Materials and Methods: The records of 238 patients with cT1-3N0 breast cancer who had an intraoperative SLN evaluation performed through One-Step nucleic acid (OSNA) assay at Songklanagarind Hospital between 1 January 2015 and 31 December 2019 were examined. Univariate and Multivariate analysis was used to identify clinicopathologic features in SLN-positive patients that predict metastasis to non-SLNs. Finally, receiver operative characteristics (ROC) curves were used to choose an optimal TTL cut-off value. Results: Of a total of 110 patients who had a positive SLN, only 48 (43.64%) were found to have positive nodes in non-SLN. Multivariate analysis revealed that lymphovascular invasion, type of SLN metastasis and SLN TTL (copies/μL) were independent predictors of positive non-SLNs.  TTL cut-off value was 19,000 copies/μL, with an AUC of 0.838 with 72.7% sensitivity and 84.7% specificity to predict non-SLN metastasis. Conclusions: The likelihood of positive non-SLNs in patients who showed a positive SLN correlates with lymphovascular invasion, type of SLN metastasis and SLN TTL (copies/μL). Our result revealed that the patients with a SLN TTL ≥19,000 copies/µl continue to attract the recommendation to proceed with ALND. This cut-off value can then help clinicians to assess which patients would benefit from ALND.     

The Pre-Treatment Neutrophil-Lymphocyte Ratio: a Useful Tool in Predicting Non-Sentinel Lymph Node Metastasis in Breast Cancer Cases

Background: The sentinel lymph node (SLN) biopsy is a highly accurate predictor of overall axillary nodal status in early breast cancer patients. There is however, still a debate on which patients with a positive SLN can benefit from axillary lymph node dissection (ALND). Numerous studies have been designed to identify variables that are predictive of non-SLN metastasis to avoid a complete ALND. The aim of this study was to determine whether the pre-treatment neutrophil-lymphocyte ratio (NLR) can be a predictive factor of non-SLN metastasis in early breast cancer patients. Materials and Methods: The records of 214 consecutive patients with cT1-3N0 invasive breast cancer who had undergone intraoperative SLN evaluation at Songklanagarind Hospital between the 1stof March 2011 and the 30thof May 2016 were examined. Data on patient demographics, tumor variables and NLR were collected and factors for non-SLN metastasis were analyzed using multivariate logistic regression. The power of the NLR was quantified with receiver operating characteristics (ROC) curves as measured by the areas under curves (AUC). Results: Multivariate analysis established presence of lymphovascular invasion (OR 8.4, 95%CI 2.3-31.3, p=0.002), macrometastasis (OR 6.6, 95%CI 1.8-24.7, p=0.005), and NLR (OR 2.3, 95%CI 1.1-4.8, p=0.033) as predictive factors of non-SLN metastasis with statistical significance. The AUC for NLR was 0.7 (95%CI 0.6-0.8) with an optimal cut-off of 2.6 giving a sensitivity of 62%, a specificity of 83.8%, a positive predictive value of 77.3% and a negative predictive value of 70.5%. Conclusion: Pre-treatment NLR is a useful diagnostic aid for predicting additional non-SLN metastasis.