Original researchBreast cancer subtypes can be determinant in the decision making process to avoid surgical axillary staging: A retrospective cohort study

•Axillary dissection is actually not indicated for positive sentinel lymph node (SLN) in selected breast cancer patients.•This study is to assess probability to have a positive lymph-node in a low risk subgroup of early breast cancer patients.•Results suggest that SLN biopsy could be avoided in triple negative subtypes and in absence of vascular/lymphatic invasions.

IntroductionThe need for performing axillary lymph-node dissection in early breast cancer when the sentinel lymph node (SLN) is positive has been questioned in recent years. The purpose of this study was to identify a low-risk subgroup of early breast cancer patients in whom surgical axillary staging could be avoided, and to assess the probability of having a positive lymph-node (LN).MethodsWe evaluated the cohort of 612 consecutive women affected by early breast cancer. We considered age, tumor 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) as variables for univariate and multivariate analyses to assess probability of there being a positive SLN o nonsentinel lymph node (NSLN). Chi-square, Fisher's Exact test and Student's t tests were used to investigate the relationship between variables; whereas logit models were used to estimate and quantify the strength of the relationship among some covariates and SLN or the number of metastases.ResultsA significant positive effect of vascular invasion and lymphatic invasion (odds ratios are 4 and 6), and a negative effect of TN (odds ratios is 10) were noted. With respect to positive NSLN, size alone has a significant (positive) effect on tumor presence, but focusing on the number of metastases, also age has a (negative) significant effect.ConclusionThis work shows correlation between subtypes and the probability of having positive SLN. Patients not expressing vascular invasion, lymphatic invasion and, moreover, a triple-negative tumor subtype may be good candidates for breast conservative surgery without axillary surgical staging.