Invasive ductal carcinoma of the breast with the "triple-negative" phenotype: prognostic implications of EGFR immunoreactivity

Invasive ductal carcinomas (IDC) of the breast with the triple negative phenotype (steroid hormone receptor absent, negative HER2 status) are characterized by poor clinical outcome. Additional tumor markers might allow identification of patients at higher risk. We evaluated clinical and biological features of 284 consecutive patients with pT1-3, pN1-3 M0 triple-negative IDC. Median follow-up was 70 months (interquartile range 59-94 months). Statistically significant worse disease-free and overall survival were observed in multivariate analysis, for patients with EGFR immunoreactivity in ≥50% invasive tumor cells (HR 2.39, 95% CI, 1.32-4.34, P = 0.004 for DFS; HR 2.34, 95% CI, 1.20-4.59 P = 0.01 for OS). Age ≥70 years and PVI were additional independent predictors of reduced overall survival. EGFR immunoreactivity significantly correlates with worse prognosis in patients with triple-negative IDC, supporting further studies on the correlation between the degree of EGFR expression and outcome of triple negative breast cancer.