Abstract A138: Association of HER2/neu with extracapsular extension of axillary lymph node metastasis in T1 to T3 breast cancer

Background: Amplification of the protein product of the HER2/neu oncogene in primary breast cancer specimens is associated with an adverse prognosis. Studies on the association of HER‐2/neu with the axillary lymph node metastasis are controversial.

Methods: From January 2000 to January 2009, 504 breast cancer patients operated in General hospital “Sveti Vracevi” in Bijeljina. We selected 253 (50,2%) patients with breast cancer who had metastases to axillary lymph nodes.

Results: Extracapsular extension (ECM) was found in 103 (40,7%). The patients were identified and divided into two groups: patients in the HER‐2 positive group (38 patients) and HER‐2 negative group (65 patients). In the HER‐2 positive group ECM was seen in 62.5% patients compared with 37.4% in the HER‐2 negative group (P = 0,059). 41 patients (39,8%) were identified with three or less lymph nodes involved, 30 patients (29,1%) patients four to six, 20 patients (19,4%) seven to nine, and 11 patients (10,6%) ten or more nodes, respectively. Total number of lymph nodes showing ECM were also significantly more in the HER‐2 positive group (48 of 81, 59.25%) vs. (13 of 60, 21.66%) in the HER‐2 negative group (P < 0,001). With a median follow‐up of 96 months factors with independent prognostic value for disease‐free survival by multivariate analysis included HER‐2/neu overexpression with extracapsular extension (P < 0.005), pN category (P < 0.01), presence of lymphovascular invasion (LVI; P < 0.005), and ECM (P < 0.001). An independent negative prognostic effect on overall survival was observed for HER‐2/neu overexpression with extracapsular extension (P < 0.05), pN category (P < 0.05), and presence of LVI (P < 0.005) and ECM (P < 0.001).

Conclusions: In patients whose tumors expressed HER‐2/neu who had positive lymph nodes and extracapsular extension prognosis was significantly worse compared with those who were HER‐2/neu negative and lymph node positive with extracapsular extension. These findings have led to the conclusion that HER‐2/neu overexpression is associated with a more aggressive subtype of cancer.

Citation Information: Cancer Prev Res 2010;3(1 Suppl):A138.