The role of amplified in breast cancer 1 in breast cancer: A meta-analysis.

PURPOSE

Amplified in breast cancer 1 (AIB1) expression is known to be involved in the initiation and progression of malignant breast cancer (BC), but its prognostic role remains uncertain. This meta-analysis assessed reported studies to evaluate this relationship.

METHODS

Electronic databases were systematically reviewed to collect eligible studies using pre-established criteria. Hazard ratios (HRs) or odds ratios (ORs) and 95% confidence intervals (CIs) were pooled to estimate the impact of AIB1 protein expression on overall survival (OS) and clinicopathologic properties of BC cases.

RESULTS

Nine eligible studies, including 6774 patients, were finally assessed by the current clinical meta-analysis. AIB1 positivity correlated with reduced OS (pooled HR = 1.409, 95% CI 1.159-1.714, P = .001). AIB1 overexpression also impacted prognosis as shown by univariate (pooled HR = 1.420, 95% CI 1.154-1.747, P = .001) and multivariate (pooled HR = 1.446, 95% CI 1.099-1.956; P = .009) analyses. Notably, subgroup analyses also revealed that AIB1 overexpression was associated with poor OS in some subgroups, such as ER-positive group (pooled HR = 1.511, 95% CI 1.138-2.006, P = .004), ER-positive without tamoxifen administration group (pooled HR = 2.338, 95% CI 1.489-3.627, P < .001), and premenopausal women group (pooled HR = 1.715, 95% CI 1.231-2.390, P = .001). Additionally, high AIB1 protein levels were associated with HER2 positivity (pooled OR = 0.331, 95% CI 0.245-0.448; P < .001), poorly differentiated histological grade (pooled OR = 0.377, 95% CI 0.317-0.448; P < .001), high Ki67 (pooled OR = 0.501, 95% CI 0.410-0.612; P < .001), presence of lymph node metastases (pooled OR = 0.866, 95% CI 0.752-0.997; P = .045), and absence of progesterone receptor (pooled OR = 1.447, 95% CI 1.190-1.759; P < .001).

CONCLUSIONS

This analysis demonstrated that AIB1 overexpression is related to aggressive phenotypes and unfavorable clinical outcomes in BC, and might involve in tamoxifen resistance. AIB1 may be a new prognostic biomarker and therapeutic target in BC.