Is sentinel lymph node biopsy more accurate than axillary dissection on staging the nodal involvement in breast cancer patients?

Today evaluation of axillary involvement can be routinely performed with the technique of sentinel lymph node biopsy (SLNB). One of the greatest advantages of SLNB is the nearly total absence of local postoperative complications. It is important to understand whether SLNB is better than axillary lymph-node dissection (ALND) for staging axillary nodal involvement. The aim of the study was to evaluate the axillary staging accuracy comparing three different methods: axillary dissection, sentinel node biopsy with the traditional 4-6 sections and sentinel node biopsy with complete analysis of the lymph node. 527 consecutive patients (525 females and 2 males) with invasive breast cancer < or = 3 cm and clinically negative axillary nodes were divided into 3 different groups: group A treated with axillary dissection, group B treated with sentinel nodal biopsy analysed with 4-6 sections, and group C treated with sentinel node biopsy with analysis of the entire node. All patients underwent a quadrantectomy to treat the tumor. Group differences and statistical significance were assessed by ANOVA. The percentages of N+ in group A and group B were 25.80% and 28% respectively, while in the third group it rose to 45%, or almost half the patients. The differences among the three groups were statistically significant (p = 0.02). From our analysis of the data it emerges that axillary dissection and sentinel node biopsy with analysis of 4-6 sections have the same accuracy in staging the nodal status of the axilla; analysis of the entire sentinel lymph node revealed an increased number of patients with axillary nodal involvement, proving more powerful in predicting nodal stage. SLNB with complete examination of the SLN removed can be considered the best method for axillary staging in breast cancer patients with clinical negative nodes. In our study, the percentage of metastases encountered after complete examination of SLN was 45% compared to the accuracy of axillary dissection that was only 25.8%. Moreover, this approach avoids the useless axillary cleaning in about 55-60% of cases, decreasing postoperative morbidity and mortality.