Immunohistochemical determination and grading of CerbB-2 expression in breast cancer: correlation with interpectoral, apical nodal involvement and other prognostic factors

We aimed to investigate the correlation between quantitative CerbB-2 expressions with conventional prognostic factors, and distinct nodal involvement in patients with invasive breast carcinoma. One hundred fifty seven consecutive breast carcinoma patients were retrospectively analysed. Level I–II, Level III, and Rotter (Interpectoral) group lymph nodes were separately examined and recorded. For each patient estrogen receptor (ER), progesteron receptor (PR), CerbB-2, P53 status were defined using immunohistochemistry. Age, tumor localisation, menopausal status, grade and the presence of intraductal component were also recorded. CerbB-2 expression did not correlate with age, localisation and menopausal status. There was a reverse, but weak correlation with tumor size and CerbB-2 expression (p=0.034). In subgroup analysis of CerbB-2 positive cases, the magnitude of CerbB-2 positivity did not correlate with tumor size (p=0.551). In univariate analysis CerbB-2 expression did not correlate with nodal involvement in Level I-II, and Rotter. In subgroup analysis of patients with positive CerbB-2, positivity of CerbB-2 linearly increased with the number of positive lymph nodes in Level I-II, and this difference was significant (p=0,039). There was a significant correlation between CerbB-2 expression and Level III nodal metastases (p=0.005). But this correlation was not significant among CerbB-2 positive patients (p=0.82). P53, PR positivity and the presence of intraductal component did not differ according to oncogene expression. We detected a reverse correlation with ER positivity and CerbB-2 positivity (p=0.011). It is concluded that quantitative expression of CerbB2 positivity increases with nodal involvement in Level I–II axillary lymph nodes, and ER. Also, CerbB-2 positivity is more common among patients with Level III lymph node metastases.