The Comparison of Different Methods of Axillary Lymph Node Analysis in Metastatic Breast Carcinomas.
Yanxia Li, Prabha Rajan, Salhadar Alia, Cagatay Ersahin. Loyola University Medical Center, Maywood, IL
Background: Status of the axillary lymph nodes (LNs) is one of the main prognostic factors in breast cancer staging. Counting the number of positive axillary LNs is the only node-related factor for evaluation of breast cancer recognized by American Joint Committee on Cancer (AJCC). However, the number of positive LNs may not completely reflect the degree of tumor involvement due to inaccurate counting in cases of matted LNs, and different tumor load in positive LNs. Therefore, to provide a more quantitative and objective estimate of LN involvement, we compared different methods of axillary LN assessment.
Design: The surgical reports and medical records of 292 breast cancer patients between 1998 to 2000 in our institution were retrospectively analyzed. We evaluated the axillary LN status by 1) counting positive LNs for N stage; 2) measuring the cross-sectional metastatic cancer area in positive LNs using computer software (Olympus MicroSuite 5); 3) calculating the percent positive LNs (# of positive LNs/# of total LNs, +LN%). Patient survival and prognosis were compared among these 3 groups by using Kaplan-Meier analysis.
Results: N stages are divided into N0, N1, N2 and N3 groups according to AJCC, cross-sectional LN cancer areas divided into <50, 50-500, >500 mm2 groups, and +LN% into <10%, 10-50%, and >50% groups. Our analysis have shown that all 3 methods can predict patient survival, in that patients with less LN involvement including N1 tumors, LN cancer area <50 mm2, and +LN% <10% have better prognosis than the ones with more LN tumor involvement (p<0.001, Fig. 1-3). However, in the groups with more LN cancer involvement, survival difference is demonstrated more apparently by the +LN% and LN cancer area methods.
Conclusions: In our study, calculating the cross-sectional LN cancer area by computer aided analysis and percentage of positive lymph nodes have shown better predictive values compared to conventional N staging system. The advance of computer technology makes the cancer area measurement quick and easy for tumor load assessment in positive LNs. Future studies with more patients are needed to clarify the role of these methods in breast cancer staging.
Monday, February 28, 2011 9:30 AM
Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 13, Monday Morning