Breast Cancer Subtypes Can Be Determinant in The Decision Making Process to Avoid Surgical Axillary Staging: A retrospective cohort study

Purpose: The need for performing axillary lymph-node dissection in earlybreast cancer when the sentinel lymph node (SLN) is positive has beenquestioned in recent years. The purpose of this study was to identify a lowrisksubgroup of early breast cancer patients in whom surgical axillarystaging could be avoided, and to assess the probability of having a positivelymph-node (LN).Methods: We retrospectively evaluated 612 consecutive women affected byearly breast cancer. We considered age, tumour size, histological grade,vascular invasion, lymphatic invasion and cancer subtype (Luminal A,Luminal B HER-2+, Luminal B HER-2-, HER-2+, and Triple Negative) asvariables for univariate and multivariate analyses to assess probability ofthere being a positive SLN o non-sentinel lymph node (NSLN). Chi-square,Fisher’s Exact test and Student’s t tests were used to investigate therelationship between variables; whereas logit models were used to estimateand quantify the strength of the relationship among some covariates andSLN or the number of metastases.Results: A significant positive effect of vascular invasion and lymphaticinvasion, and a negative effect of TN were noted. With respect to positiveNSLN, size alone has a significant (positive) effect on tumour presence, butfocusing on the number of metastases, also age has a (negative) significanteffect.Conclusion: This work shows correlation between subtypes and theprobability of having positive SLN. Patients not expressing vascular invasion,lymphatic invasion and, moreover, a triple-negative tumor subtype may begood candidates for breast conservative surgery without axillary sur