Clinicopathological and prognostic significance of FOXP3+ tumor infiltrating lymphocytes in patients with breast cancer: a meta-analysis.

Background: The prognostic significance of FOXP3+ tumor-infiltrating lymphocytes (TILs) in patients with breast cancer remains controversial. The aims of our meta-analysis are to evaluate its association with clinicopathological characteristics and prognostic significance in patients with breast cancer.

Methods: PubMed, Embase, Cochrane Database and the Ovid Database were systematically searched (up to April 2015). The meta-analysis was performed using hazard ratio (HR), odds ratio (OR) and 95 % confidence intervals (CI) as effect measures. Using the random-effects model, statistical analysis was performed using Stata software, version 12.0.

Results: Seventeen studies including 8277 patients with breast cancer were analyzed. The meta-analysis indicated that the incidence difference of FOXP3+ TILs was significant when comparing the lymph node positive group to negative group (OR = 1.305, 95 % CI [1.071, 1.590]), the histological grade III group to the I-II group (OR = 3.067, 95 % CI [2.288, 4.111]), the ER positive group to the negative group (OR = 0.435, 95 % CI [0.287, 0.660]), the PR positive group to the negative group (OR = 0.493, 95 % CI [0.296, 0.822]), the HER2 positive group to the negative group (OR = 1.896, 95 % CI [1.335, 2.692]), the TNBC group to the non TNBC group (OR = 2.456, 95 % CI [1.801, 3.348]). The detection of FOXP3+ TILs was significantly correlated with the recurrence-free survival (RFS) of patients (HR = 1.752, 95 % CI [1.188-2.584]) and the overall survival (OS) of patients (HR =1.447, 95 % CI [1.037-2.019]).

Conclusions: Our meta-analysis demonstrates that the presence of high levels of FOXP3+ TILs is associated with prognosis for breast cancer patients and predicts lymph node metastasis, hormone receptor and HER-2 status.