OBJECTIVETo study the significance of interleukin-1beta (IL-1beta) expression and microvascular density (MVD) in invasive micropapillary carcinoma (IMPC) of breast.

METHODSImmunohistochemical study for IL-1beta and CD34 was performed on 100 cases of IMPC and 97 cases of invasive ductal carcinoma (IDC). The relationship between IL-1beta expression, MVD and various pathologic parameters (estrogen and progesterone receptor status, Ki-67 proliferative index, histologic grade and lymph node metastasis) in IMPC was analyzed.

RESULTSThere was no significant difference in expression of IL-1beta between IMPC and IDC (P = 0.924). The expression of IL-1beta positively correlated with proliferative index (P = 0.023), histologic grade (P = 0.038) and lymph node metastasis (P = 0.008), and negatively correlated with estrogen receptor expression (P = 0.035). The MVD in IMPC was significantly higher than that in IDC (66.4 versus 60.0, P = 0.003). The mean MVD in node-positive IMPC was higher than that in node-negative IMPC (68.8 versus 54.4, P = 0.001). In IMPC, the MVD in histologic grade II and III tumors was much higher than that in histologic grade I tumors (68.3 versus 59.9, P = 0.025). It had no relationship with hormonal receptor status and proliferative index.

CONCLUSIONOverexpression of IL-1beta and high microvessel density may have important roles in tumor cell proliferation and lymph node metastasis in IMPC.