High expression of maspin is associated with early tumor relapse in breast cancer

Maspin is a serine protease inhibitor with tumor suppressor activity. Maspin can suppress tumor growth and metastasis in vivo and tumor cell motility and invasion in vitro. Maspin also modulates apoptosis of tumor cells, possibly by modulating the expression of the B-cell lymphoma-2 family member. p53 regulates the expression of the tumor suppressor gene maspin. Breast cancer is known for its propensity to recur even after decades. The biology behind this phenomenon of tumor dormancy is poorly understood. This study was conducted to clarify the role of maspin and B-cell lymphoma-2 in early and late recurring breast cancer. The expression of maspin, B-cell lymphoma-2, p53, and estrogen receptor was studied by immunohistochemistry in 73 primary breast cancers and in their metastatic relapses detected within 2 years, or 5 or 10 years after primary surgery. The cytoplasmic expression of maspin was significantly higher in the primary tumors of the early metastasizing breast cancers (first tumor relapse within 2 years) and also in their metastases compared to late metastasizing cancers. An opposite activity was observed in the expression of B-cell lymphoma-2. The level of B-cell lymphoma-2 staining was lower in the early relapsing cancers and significantly lower in their metastases, compared to tumors which metastasized 5 or 10 years after primary surgery. High cytoplasmic expression of maspin and low expression of B-cell lymphoma-2 in primary breast cancer predict early tumor relapse.