1133 Background: Completion axillary lymph node dissection (ALND) is currently the standard of care in the event of a positive sentinel lymph node biopsy (SLNB). However, result from Z0011 indicate that women with a one or two involved axillary nodes and clinical T1-T2 tumors undergoing lumpectomy with radiation therapy followed by systemic therapy do not benefit from completion of ALND in terms of survival. The purpose of this study was to define possible predictors of having three or more involved axillary node to provide information for surgeons making decision about sparing intraoperative frozen section analysis of sentinel lymph node and completion ALND. Methods: We reviewed the records of 1215 patients with clinical T1-T2 invasive breast cancer. None of these patients were in situ cancer on initial gun biopsy nor received neoadjuvant chemotherapy. Factors associated with having three or more involved axillary nodes were evaluated by univariate and multivariate logistic regression analysis. Results: Among 1215 patients, 321 patients had three or more positive nodes. On a multivariate analysis, having three or more positive nodes was associated with primary tumor size by breast US, axillary LN grade according to cortical thickness by US, presence of axillary LN enlargement on chest CT and age. A scoring system to predict the probability of having three or more nodes based on patients’ data and preoperative image findings was developed from the multivariate logistic regression model. The area under the ROC curve was 0.827 (95% CI: 0.793-0.860), and negative predictive value was 90.2% for a score ≤2.7. Similar findings were observed for a validation dataset of 505 patients. Conclusions: Patients with a low probability of having three or more positive nodes can be identified from preoperative image finding. The scoring system developed will be helpful to surgeons making decision about sparing intraoperative frozen section analysis of sentinel lymph node and completion ALND.
Frozen section analysis and sentinel lymph node biopsy in well differentiated thyroid cancer
