Predictors of Sentinel Node Involvement in Breast Cancer

Sentinel lymph node biopsy has shown to be a good alternative procedure for axillary lymph node dissection and to lead to lower frequency of morbidity, though this technique has its own side effects. It needs especial equipment and may not be available in some medical centers, especially in developing countries. This study aimed to identify a subgroup of patients with higher probability of metastasis to sentinel lymph node that can be excluded from indications of this procedure. In this cross-sectional study, the clinical data of 195 patients with breast cancer who underwent sentinel lymph node biopsy in Tehran, Iran, between 2009 and 2011 were reviewed. Whenever tumor features showed significant association with sentinel node metastasis in univariate analyses, logistic regression was used to identify independent predictors. Univariate analyses revealed that tumor size and lymphovascular invasion have significant association with sentinel lymph node metastasis (P = 0.009 and P < 0.001, respectively). Moreover, age had an significant association with positive sentinel lymph node biopsy (SLNB) (P = 0.004). Other factors, including tumor grade, estrogen receptor, progesterone receptor, and human epidermal growth factor receptor-2, were not associated with positive sentinel lymph node biopsy in univariate analysis. All factors that showed significant association in univariate analysis remained statistically significant predictors of positive SLB in multivariate analysis. It seems that young breast cancer patients, those who have tumors larger than 5 cm and those with lymphovascular invasion, are at an increased risk of sentinel lymph node metastasis.