P3-07-41: Sentinel Lymph Node Biopsy Is a Reliable Method for Lymph Node Evaluation in Neoadjuvant Chemotherapy Treated Breast Cancer Patients.

Abstract

Abstract Background: Successful sentinel lymph node mapping in breast cancer patients treated with neoadjuvant chemotherapy has been debated by practicing surgeons due to the potential compromise of the lymphatic drainage system after treatment. Furthermore, whether clinicopathologic variables associated with sentinel lymph node positivity in breast cancer patients differ from similar patients who have been treated with neoadjuvant chemotherapy has not been well-studied. Materials and Methods: Breast cancer patients who received neoadjuvant chemotherapy were identified in our files. A similar number of breast cancer patients who did not receive such therapy was also selected as a comparison group. Clinicopathologic parameters such as age, type of surgical procedure, number of sentinel lymph nodes removed and/or positive, number of non-sentinel lymph nodes removed and/or positive, tumor size, histologic type/grade, presence of lymphovascular invasion, biomarker expression (ER,PR, HER-2/neu) and multifocality were recorded for each patient in both cohorts. Statistical analysis was performed for each cohort to identify variable(s) that correlated with sentinel lymph node positivity. Additional analysis was performed by computing the odds ratio of sentinel lymph node positivity after adjusting for selected variables. Results: Ninety-seven and ninety-three patients who were and were not treated with neoadjuvant chemotherapy, respectively, were identified. In all patients, successful sentinel lymph node mapping was achieved. When these cohorts were separately analyzed, tumor size, lymphovascular invasion, and non-sentinel lymph node positivity were associated with sentinel lymph node positivity in the cohort that did not receive neoadjuvant chemotherapy. In the cohort that received therapy, lymphovascular invasion and non-sentinel lymph node positivity were associated with sentinel lymph node positivity. In addition, after adjusting for tumor size, lymphovascular invasion and histologic grade, patients treated with neoadjuvant chemotherapy were more likely to have sentinel lymph node positivity than those who did not have this treatment (odds ratio: 5.4, 95% CI 2.4, 12.1). Conclusions: Successful sentinel lymph node mapping was achieved in all ninety-seven breast cancer patients studied. Regardless of whether neoadjuvant chemotherapy was administered, the presence of lymphovascular invasion and non-sentinel lymph node positivity were found to predict sentinel lymph node positivity. By comparing two cohorts of breast cancer patients differing only in the use of neoadjuvant chemotherapy and adjusting for select variables, those in the treated cohort still remained more likely to have a positive sentinel lymph node. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P3-07-41.