Older age independently predicts a lower risk of sentinel lymph node metastasis in breast cancer

Background: The influence of patient age on the risk of sentinel lymph node (SLN) metastasis in breast cancer has not been defined. Methods: A breast cancer SLN database was analyzed. Factors associated with SLN metastasis were assessed by multiple logistic regression modeling. Age, T stage, estrogen receptor status, HER-2/neu status, grade, angiolymphatic invasion, lobular histology, tubular/mucinous histology, and the number of SLNs resected were assessed. Results: Data were available for 810 patients with invasive breast cancer. SLN metastasis was observed in 22% of the patients. The factors most strongly associated with SLN metastasis were angiolymphatic invasion, T stage, and age. Age ranged from 29 to 95 years. The median age was 66 years. Overall, SLN metastasis was more common in younger patients (<= 66 years) than in older patients (> 66 years; P < .001). Among patients without angiolymphatic invasion, SLN metastasis was nearly twice as common in the younger patients as in the older patients. The effect of angiolymphatic invasion as a risk for SLN metastasis was much greater in the older age group. Conclusions: In addition to known risk factors, age independently predicts the risk of SLN metastasis in breast cancer. Angiolymphatic invasion seems to be a more powerful predictor of SLN metastasis in older patients.