OBJECTIVETo investigate the expressions of FOXC1 and matrix metalloproteinase 7 (MMP-7) in different molecular subtypes of breast cancer and their association with clinicopathological characteristics of the disease.

METHODSBased on immunohistochemical results of ER, PR, HER2, CK5/6, CK14 and EGFR, 105 breast cancer patients were classified as 4 subtypes: luminal, HER2 positive, basal-like subtype (BLs) and normal breast-like subtype (NBLs). The association of FOXC1 and MMP-7 expressions with clinicopathological parameters in different molecular subtypes was analyzed.

RESULTSOut of 105 patients with breast cancer, the subtypes of luminal, HER2 positive, BLs and NBLs accounted for 52.4% (55/105), 16.2% (17/105), 17.1%(18/105) and 14.3% (15/105), respectively. Patients with luminal and/or NBLs subtypes had significantly higher 5-year survival rate than those with HER2 positive and/or BLs did (log-rank=22.161, P<0.01). The overall positive expression rate of FOXC1 was 26.7% (28/105) and the expression was higher in BLs patients than that in other subgroups (χ²=30.108, P<0.01). The expression of FOXC1 was correlated with histological grade, tumor size, distant metastasis and 5-year survival rate of breast cancer. The overall positive expression rate of MMP-7 was 67.6% (71/105) and the expression of MMP-7 was also higher in BLs patients than that in other molecular subtypes (χ²=11.328, P<0.05). The positive expression of MMP-7 was correlated with metastasis in ipsilateral axillary lymph nodes, distant metastasis and 5-year survival rate of the patients. FOXC1 was correlated with MMP-7 (r=0.325, P<0.01).

CONCLUSIONPatients with luminal and/or NBLs breast cancer have more favorable prognosis than those with HER2 positive and/or BLs subtypes. The expressions of FOXC1 and MMP-7 are closely correlated with the clinicopathological features of breast cancer patients.