High tumor-infiltrating FoxP3+ T cells predict poor survival in estrogen receptor-positive breast cancer: A meta-analysis

Abstract

Aims: Tumor-infiltrating FoxP3⁺ T cells and FoxP3⁺ tumor cells have been reported in breast cancer (BC), which impaired immunity and promoted tumors progression. However, their prognostic value for survival in patients with breast BC remains controversial.

Methods: A meta-analysis was performed. Original data included the hazard ratios (HR) of overall survival (OS), relapse-free survival and odds ratio (OR) in BC patients. We pooled HR/OR with 95% confidence intervals (CI) to estimate the hazard.

Results: The overall survival of high tumor-infiltrating FoxP3⁺ T cells patients was lower than low tumor-infiltrating FoxP3⁺ T cells patients with estrogen receptor (ER)-positive (HR 0.86, 95% CI 0.77-0.96; P = 0.009) but not ER-negative (HR 1.09, 95% CI 0.82-1.45; P = 0.569) BC. And FoxP3⁺ tumor cells were not associated with the overall survival and recurrences of BC patients (P > 0.05). In addition, a significant association was revealed between high tumor-infiltrating FoxP3⁺ T cells and grade (I + II/III: OR 0.31, 95% CI 0.17-0.56; P < 0.001), ER status (present: OR 2.39, 95% CI 1.51-3.76; P < 0.001), HER2 status (present: OR 0.53, 95% CI 0.36-0.78; P = 0.001), PR status (present: OR 1.88, 95% CI 1.31-2.71; P < 0.001). And a significant association was revealed between positive FoxP3⁺ tumor cells and Nodal status (present: OR 0.48, 95% CI 0.23-0.97; P = 0.04), grade (I + II/III: OR 0.44, 95% CI 0.22-0.85; P = 0.01), PR status (present: OR 2.37, 95% CI 1.54-3.36; P < 0.001).

Conclusions: High tumor-infiltrating FoxP3⁺ T cells were associated with a poorer prognosis for ER-positive BC, but not for ER-negative BC.

Keywords: Breast cancer; Estrogen receptor; FoxP3; Prognostic.