Abstract. Mucinous breast carcinoma (MBC) is a rare type of breast cancer, but it has been infrequently studied due to its associated good prognosis. Vascular endothelial growth factor (VEGF) and caspase-3 have been identified to be prognostic factors of infiltrating ductal carcinoma-not otherwise specified (IDC-NOS), but their expression in MBC has not been reported. In the present study, the expression of caspase-3 and VEGF in MBC and IDC-NOS were assessed by immunohistochemistry. Scoring was conducted based on staining intensity and percentage of positive cells. Based on the scores of caspase-3 and VEGF expression, all patient samples were divided into two groups: Low expression (score of 0-5) or high expression (score of 6-12). In total, 42.59% of MBC patients exhibited a high VEGF score compared with 61.67% of the IDC-NOS group (P<0.05). Furthermore, 57.41% of MBC patients exhibited high caspase-3 expression compared with only 33.33% of IDC-NOS patients (P<0.05). VEGF expression in MBC was associated with age, nodal status and tumor-node-metastasis (TNM) stage. Cox univariate analysis showed that higher VEGF expression, positive nodal status and higher TNM stage were associated with shorter disease-free survival (DFS). The Kaplan-Meier method showed that higher VEGF expression in MBC was associated with worse DFS times, while Cox multivariate analysis showed that only TNM stage was significantly associated with DFS. VEGF and caspase-3 expression varied in the MBC and IDC-NOS samples, but neither was directly correlated with DFS in the MBC patients.
IntroductionMucinous breast carcinoma (MBC), also known as colloid carcinoma, is a rare subtype of breast tumors that accounts for 1-7% of all breast cancer cases. MBC is characterized by the presence of extracellular mucin (MUC) (1). MBC includes mixed MBC, consisting of other cancer types such as invasive ductal carcinoma, and pure MBC (PMBC), in which the entire mass is almost occupied by mucinous cancer cells and is without conventional invasive ductal carcinoma cells (2). PMBC is represented by a mass with a >90% mucinous component (3). MBC is linked with a more favorable prognosis, a longer disease-free interval and a lower incidence of axillary node metastasis compared with infiltrating ductal carcinoma-not otherwise specified (IDC-NOS) (1,2,4). However, recurrence and metastasis of MBC are frequently present in clinical practice.Angiogenesis is a prerequisite for tumor development; there is a close association between the formation of blood vessels in the vicinity of tumor cells and the potential for tumor formation, invasion and metastasis. Angiogenesis is induced and developed in response to two sets of extracellular signals: soluble angiogenic factors and the extracellular matrix (5). Breast carcinoma has been shown to be an angiogenesisdependent tumor through experimental and clinical data. Vascular endothelial growth factor (VEGF) is the most potent endothelial cell mitogen (6) and a regulator of vascular permeability, therefore, VEGF has been consid...