Purpose: To investigate the relationships, if any, between interleukin (IL) -8/matrix metalloproteinase (MMP)-2/ MMP-9 and other prognostic variables in lymph node-negative untreated breast cancer patients, and to determine the prognostic value of these potential biomarkers.
Methods: The study included 135 patients with known clinicopathological parameters. IL-8, MMP-2 and MMP-9 levels were determined by ELISA in primary tumor tissue lysates.
Results: There were no significant relationships between IL-8/MMP-2/MMP-9 expression and available clinicopathological parameters (patient age, menopausal status, tumor size and tumor grade). Estrogen receptor (ER)- patients had higher levels of both IL-8 and MMP-9 (p=0.006 and p=0.04, respectively) compared to ER+ patients; there was a significant negative correlation between ER and IL-8 (p=0.02). MMP-9 expression was significantly higher in patients with higher levels of IL-8 (p<0.001) and there was a significant positive correlation between IL-8 and MMP-9, as well as between progesterone receptor (PR) and MMP-2 (p<0.001 and p=0.05, respectively). PR+ patients had higher levels of MMP-2 than PR- patients (p=0.03). Among the investigated biomarkers, only IL-8 had a statistically significant prognostic value in terms of relapse free survival (RFS) (p<0.001). Patients with higher levels of IL-8 had worse prognosis.
Conclusions: Expression of IL-8 and consequently expression of MMP-9 could be hormonally regulated in breast cancer. IL-8 could be a marker of more aggressive, ER- breast cancer phenotype. Different expression of MMP-2 and MMP-9 regarding differential hormonal receptor expression could indicate distinct mechanisms of their regulation. It seems that IL-8 is a strong and independent unfavorable prognostic parameter in node-negative breast cancer. Node-negative patients with higher levels of IL-8 should be treated with adjuvant, especially IL-8 targeted therapy.