Omission of axillary dissection after a positive sentinel node dissection may influence adjuvant chemotherapy indications in operable breast cancer patients.

BACKGROUND: This study was designed to evaluate how the omission of axillary dissection would have altered the indication for adjuvant chemotherapy (ACT) in patients with early breast cancer submitted to conservative surgery with one or two positive sentinel lymph nodes (SLNs).

METHODS: We identified 321 women in our institutional database who fulfilled the characteristics. All underwent completion axillary lymph node dissection (AD). Each case was blindly reviewed by our breast team in two rounds, and the total number of positive lymph nodes was disclosed only in the second. At each round, the panel chose between: (1) recommend, (2) discuss, (3) do not recommend ACT. Changes between round 1 and 2 were studied by the marginal homogeneity test. Exploratory logistic regression analyses were performed to study predictors of non-SLN involvement and of changes in the indication for ACT.

RESULTS: AD revealed non-SLNs metastases in 96 patients (30 %). Fifty-two patients (16 %) had their initial indication changed at round 2 (p < 0.001). Most of the changes were toward ACT (83 %), and all except two occurred in patients with immunohistochemically defined luminal A and luminal B/HER2-negative tumors. In these two subgroups, a Ki67 above the median value (21 %) was the only independent predictor of no change in the indication to ACT at round 2.

CONCLUSIONS: Omission of AD in patients with one or two positive SLNs may change the indication to ACT in a significant proportion of patients with hormone receptor-positive/HER2-negative tumors. All implications should be taken into account before abandoning AD, including a possible biologically tailored surgical approach.