Expression of S100A4 and Met: potential predictors for metastasis and survival in early-stage breast cancer.

BACKGROUND: To formulate individually tailored therapy for patients with early-stage breast cancer, it is necessary to identify biomarkers for predicting metastasis and survival.

METHODS: A homogeneous cohort of 92 T1-2N0M0 breast carcinoma patients with a long-term follow-up were divided into two groups: the metastasis group (n = 41) and the disease-free group (n = 51). We evaluated the ability of risk discrimination of six biomarkers, including S100A4, Met, bcl-2, p53, survivin, and HER-2/neu, in early-stage breast cancer.

RESULTS: In multiple logistic regression analysis, only S100A4 expression (odds ratio = 5.37, p = 0.008) and Met expression (odds ratio = 6.91, p = 0.002) were independent predictors of distant relapse. Multivariate Cox models showed S100A4 and Met expressions were associated with 10-year disease-free survival (DFS) (risk ratio 3.2 and 4.0, respectively); however, tumor size and histological grade were not significant predictors. The 10-year DFS of T1-2N0M0 patients was 55.4%. T1-2N0M0 patients with S100A4-positive tumors had a significantly worse 10-year DFS than those with S100A4-negative tumors (29.0 vs. 68.9 %, p = 0.001). The 10-year DFS in T1-2N0M0 patients with Met-negative tumors was 82.4 vs. 39.7% if Met expression was positive (p = 0.0002). S100A4, but not Met, was still a significant predictor of 10-year DFS in T1N0M0 breast carcinoma patients (p = 0.02). For the T2N0M0 subgroup, both S100A4 and Met were significantly correlated with survival. The 10-year DFS of T2N0M0 patients with S100A4-negative and Met-negative tumors was 92.3%; in those with S100A4-positive and Met-positive tumors, however, it was only 11.8%.

CONCLUSIONS: S100A4 expression is an indicator of a poor prognosis for T1N0M0 breast cancer. In addition, the combination of S100A4 and Met expression gives the best risk group discrimination in the T2N0M0 subgroup. S100A4 expression appears to be an earlier step in the metastatic progression compared to Met expression in early-stage breast carcinoma.