Abstract
This study examined the associations between GRP78 expression and breast cancer recurrence and survival in patients treated with anthracyclines in the adjuvant setting. GRP78 expression was assessed in 106 stage II/III breast cancer patients. Tissue microarray was used to perform immunohistochemistry and to determine the GRP78 expression in endoplasmic reticulum and cell membrane of breast tumors. Four distinct scenarios (low and high thresholds) were developed. For high thresholds, 16% and 40% of our cases were GRP78-positive for endoplasmic reticulum and cell membrane, respectively. For low thresholds, 74% and 87% of our cases were GRP78-positive for endoplasmic reticulum and cell membrane, respectively. In the endoplasmic reticulum high-threshold scenario, GRP78 positive was found to be significantly frequent in T3 tumors (p=0.02), and inversely related to ERBB2 overexpression (p=0.03). There was a lower proportion of GRP78-positive cases among women between 50 and 65 years of age (p=0.02). In the endoplasmic reticulum low-threshold scenario, the proportion of GRP78-positive cases was significantly higher in women younger than 50 years and in those who were premenopausal (p=0.04). No statistically significant difference was found in survival probabilities among the scenarios examined. In our cohort, GRP78 overexpression was not a predictor of overall or disease-free survival of patients receiving anthracycline-based adjuvant chemotherapy.