This study identifies clinical and pathologic factors
predictive of having ≥4 involved axillary lymph nodes in breast
cancer patients with a positive sentinel node
. These factors
may influence radiation therapy decisions.
We reviewed the records of 201 patients with positive SLN who underwent axillary dissection; 34 of these patients had ≥4 positive axillary lymph nodes. Factors
associated with ≥4 lymph nodes were evaluated by χ2
test, and multivariate logistic regression model was used to identify independent factors
On univariate analysis, presence of lymphovascular space invasion, extracapsular extension, increased number of positive SLN, increased size of tumor, macrometastases within the SLN, and decreased number of negative SLN were all significantly associated with having ≥4 involved axillary lymph nodes. On multivariate analysis, presence of extracapsular extension (odds ratio [OR] = 3.76, P
= 0.004), increased number of positive SLN (OR = 3.99, P
= 0.006), increased size of tumor (OR = 3.33, P
= 0.011 for size of 2.1 to 5 cm and OR = 8.28, P
= 0.018 for size >5 cm), and decreased number of negative SLN (OR = 2.62, P
= 0.037) were found to be significant.
We have identified primary tumor and SLN variables that predict for a greater probability of having a significant burden of residual disease in the axilla that may affect treatment recommendations.