The Prognostic Value of HER2-Positive Circulating Tumor Cells in Breast Cancer Patients: A Systematic Review and Meta-Analysis

A meta-analysis was conducted to determine the prognostic value of HER2-positive circulating tumor cells (CTCs) in patients with breast cancer. MedLine, Central, and Embase databases were searched. HER2-positive CTCs were associated with worse overall survival, but not worse progression-free survival. HER2-positive CTCs have prognostic value in patients with breast cancer. Introduction A meta-analysis was conducted to determine the prognostic value of HER2-positive circulating tumor cells (CTCs) in patients with breast cancer. Materials and Methods MedLine, Central, and Embase databases were searched. Inclusion criteria were: (1) randomized controlled trials, 2-arm prospective studies, and retrospective studies; (2) patients with breast cancer; (3) HER2-positive CTCs were examined; and (4) hazard ratio (HR) of survival between patients with HER2-positive and HER2-negative CTCs was reported. Results Four studies with a total of 550 patients with stage I to IV breast cancer were included. HER2-positive CTCs were not associated with worse overall survival (OS; HR, 1.489, 95% confidence interval [CI], 0.873-2.540, P = .144) or progression-free survival (PFS; HR, 1.543; 95% CI, 0.636-3.744; P = .338). In patients without metastasis, HER2-positive CTCs were associated with worse OS (HR, 2.273; 95% CI, 1.340-3.853; P = .002) and worse PFS (HR, 2.870; 95% CI, 1.298-6.343; P = .009). There was no significant relationship between HER2-positive CTCs and survival in subgroups of patients with metastasis. Conclusion HER2-positive CTCs have prognostic value in patients with breast cancer and without distant metastasis.