Ratio between positive lymph nodes and total excised axillary lymph nodes as an independent prognostic factor for overall survival in patients with early breast cancer

Abstract

e22084 Background: The status of the axillary lymph nodes (ALN) in early (stage I and II) breast cancer (BC) patients remains the single most important determinant of overall survival (OS). While the absolute number of positive ALN has been demonstrated to have a significant prognostic impact, new emerging data supports the role of axillary lymph node ratio (ALNR) as an independent prognostic indicator of OS. Methods: We conducted a single-center retrospective review of 1,255 BC patients and analyzed 930 patients with early BC admitted to American University of Beirut Medical Center between 1983 and 2001. Data included age at diagnosis, type of mastectomy, ALN involvement, use of chemotherapy, hormonal therapy, post-operative radiation therapy, tumor size, histological type and grade, lympho-vascular invasion status, hormonal receptor status, and Her-2/neu overexpression and the calculated ALNR (number of positive ALN / total number of excised ALN). Patients were subdivided into 3 groups according to ALNR value (< 0.25, 0.25–0.49, 0.50–1.00). The status of the axillary lymph nodes was analyzed with respect to 5- and 10-year OS. Results: On univariate analysis both the absolute number of positive ALN and the ALNR were significant predictors of OS .The 5- year OS of patients with ALNRs of < 0.25, 0.25–0.49 and 0.50–1.00 was 88%, 72% and 65 % respectively and the 10-year OS was 83%,54% and 51 % respectively . On multivariate analysis only the ALNR remained an independent predictor of overall survival, with a 2.7- and 3.16-fold risk of dying at ALNRs of 0.25 and 0.5, respectively. Conclusions: Our study demonstrated that the ALNR is a stronger factor in predicting OS than the absolute number of positive axillary lymph nodes. ALNR may aid in subdividing patients with positive ALN into low and high risk groups, with potential implications on their subsequent adjuvant management. No significant financial relationships to disclose.