Abstract
Elevated levels of resistin and epidermal growth factor receptor (EGFR) facilitate the development of breast cancer, although there are no reports of any correlation between these proteins. This study analyzed 392 human breast cancer tissue specimens and 42 samples of adjacent normal tissue. Rates of positive and strongly positive resistin expression were significantly higher in breast cancer tissue than in the adjacent nontumor tissue (83.2% vs. 23.8% and 20.9% vs. 0.0%, respectively; P < 0.001 for both comparisons). Positive resistin expression was significantly associated with tumor size, grade, stage, estrogen receptor (ER), progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2) status, and molecular classification; strongly positive resistin expression was associated with tumor grade, ER, PR, HER2 status, and molecular classification. Significantly positive correlations were observed between positive and strongly positive resistin expression and corresponding levels of EGFR expression. Relapse-free and overall survival was worse for patients with high levels of both proteins than for those with high levels of only one protein or normal levels of both proteins. Our evidence suggests that combined high levels of resistin and EGFR expression correlate with survival in patients with breast cancer.