Extranodal Extension in Metastatic Axillary Lymph Nodes among Breast Cancer Patients
Y Li, B Sanchez, AS Godambe, K Albequerque, P Rajan, CH Ersahin. Loyola University Medical Center, Maywood, IL; Radiation Oncology, Maywood, IL
Background: The number of positive lymph nodes (LN) is the only node-related prognostic factor for breast cancers recognized by the AJCC. Additional node-related factors have been evaluated by many groups. Our current pilot study aimed at characterizing extranodal extension with the associated tumor features, while our future studies will focus on the clinicopathologic correlation of extranodal extension to serve as a surrogate for survival.
Design: We analyzed data from patients diagnosed with invasive breast cancer between years 1998-2000. 292 patients were divided into 3 groups: 1) Patients with negative LNs (NoMet) group (56%), 2) Patients with positive LNs but without extranodal extension (MetNoExtraN) group (14%), 3) Patients with positive LNs and extranodal extension (MetExtraN) group (30%).
Results: A large percentage (68%) of patients with metastatic breast cancer to the LNs showed extranodal extension. Our studies found the number of positive LNs to be significantly higher in MetExtraN than in MetNoExtraN (Table 1), while the total number of LNs examined are not different between these 2 groups. Also, the maximum dimension of the positive LNs is larger in MetExtraN.
Table 1: Mean numbers and size of axillary lymph nodes***p<0.0001, **p=0.006, Mann-Whitney
|# Positive LNs||# Total LNs||Max Dimension (cm)|
The mean tumor size of NoMet group was 1.9 cm, smaller than that of MetNoExtraN (3.1) and MetExtraN (3.3), but there was no significant difference between the latter two groups (Mann-Whitney). Comparison of Nottingham grades showed statistical difference only between NoMet and MetExtraN group (Table 2).
Table 2: Age and percentage of Nottingham grades***p= 0.0009, Chi-square
|Mean Age||Grade 1||Grade 2||Grade 3||Total|
Conclusions: Our data suggest that although the total number of examined LNs, the Nottingham grades, and the tumor size were the same in breast cancers with and without extranodal extension, the MetExtraN group distinguishes itself with more positive LNs and larger tumor volume in the metastatic lymph node. The finding of extranodal extension may play an important role in patient's treatment and prognosis, which will be further investigated in our studies.
Tuesday, March 10, 2009 9:30 AM
Poster Session III # 71, Tuesday Morning