OBJECTIVETo evaluate the clinical value of HER2 overexpression in breast cancer and its prognostic implication in patients with lymph node negative breast carcinoma.

METHODSThe following electronic database were extracted using appropriate inclusive and exclusive standards: Cochrane library, PUBMED, Embase (1984 - 2003), OVID, CMCC and CNKI. Excel and RevMan 4.2 were used for statistical analysis.

RESULTSFifty-six articles were extracted to calculate the positive rate of HER2 overexpression. The pooled positive rate was 23.14% [19.54%, 26.73%], with positive immunohistochemistry (IHC) rate of 23.13% [19.49%, 26.77%] and positive FISH rate of 20.90% [15.54%, 26.25%]. Seven articles were used to evaluate prognostic predication of HER2 expression. It was concluded that in patients with lymph node negative breast carcinoma, HER2 overexpression (both IHC and FISH) independently predicted a poor prognosis based on disease-free survival (DFS) and overall survival (OS) with a P < 0.05. For DFS, the pooled RR was 1.38 [1.07, 1.80] with 1.16 [1.02, 1.31] for IHC and 1.98 [1.56, 2.52] for FISH. For OS, the pooled RR was 1.58 [1.16, 2.14] with 1.37 [1.14 to 1.64] for IHC and 2.33 [1.45 to 3.75] for FISH. HER2 overexpression effectively predicted DFS/OS of patients without adjuvant therapy and OS of patients with the therapy, but not for DFS, with the pooled RR of 1.46 [1.02, 2.09] and 1.11 [0.95, 1.31] for DFS, respectively and the pooled RR of 1.93 [1.44 to 2.58] and 1.25 [1.01, 1.56] for OS, respectively.

CONCLUSIONSIn patients with lymph node negative breast carcinoma, the positive rate of HER2 overexpression is 23.14%. HER2 overexpression indicates a poor prognosis and adjuvant therapy after surgery should be recommended.